UNIPROT:P56851 - FACTA Search

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Query: UNIPROT:P56851 (epididymal)
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Adult male albino rats were treated with 0.4 mg nicotine/100 g body weight either orally or intraperitoneally for 30 days. All animals were autopsied on the 31st day. Epididymis and vas deferens were dissected out, weighed and processed for biochemical estimations. Nicotine caused a reduction in the weight of epididymis and vas deferens in both drug treated groups. The total cholesterol content is increased while protein, DNA and RNA contents and the epididymal sperm count were decreased. The acid phosphatase content is also decreased, whereas alkaline phosphatase is increased. The surface epithelial cell height of these ducts is decreased and secretory activity is reduced with the disruption of epithelial cell projections. These changes may be due to non-availability of androgens in nicotine treated rats.
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PMID:Nicotine induced inhibition of the activities of accessory reproductive ducts in male rats. 961 35

Galactosyltransferase activity was measured in the luminal plasma of the cauda epididymidis of mice, rats, rabbits, rams and boars, and in the rete testis fluid of rams and boars. The activities of nucleotide pyrophosphatase and alkaline phosphatase, which compete with galactosyltransferase for substrate, were also determined. In these species, galactosyltransferase activity in the luminal plasma of the cauda epididymidis was similar when the inhibitory effect of pyrophosphatase and phosphatase was minimized by assay conditions. However, under assay conditions that did not minimize the effect of these enzymes, the galactosyltransferase activities of these species were very different and were inversely correlated with the activities of pyrophosphatase and phosphatase. The ratio of galactosyltransferase activity to pyrophosphatase and phosphatase activity was much higher in the rete testis fluid than in the luminal plasma of the cauda epididymidis in both rams and boars. In rams, galactosyltransferase in the luminal plasma of the cauda epididymidis was more heat resistant than that in serum. These results suggest that there is a species difference in the availability of galactosyltransferase activity in the luminal plasma of the cauda epididymidis and that in some species, galactosyltransferase in the luminal fluid is unlikely to have any function. The results are also discussed with respect to the possible function of galactosyltransferase, pyrophosphatase and phosphatase in epididymal luminal plasma and rete testis fluid.
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PMID:Galactosyltransferase, pyrophosphatase and phosphatase activities in luminal plasma of the cauda epididymidis and in the rete testis fluid of some mammals. 1007 Mar 58

The pathogenesis of the aberrant development of the male genital tract (epididymis, vas deferens and seminal vesicles) seen in patients with congenital bilateral absence of the vas deferens (CBAVD) is still unclear. Since men with CBAVD carry mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR), it is likely that CFTR mRNA of the translated protein plays a major role in the pathogenesis of CBAVD. The aim of this study was to compare the pattern of expression of CFTR mRNA in epididymides of men with CBAVD and other types of obstruction (post-vasectomy and post-inflammatory) with that of normal non-obstructed adult epididymis. Epididymal biopsies were obtained at the time of microsurgical epididymal sperm aspiration procedures or during vaso-epididymostomy reanastomosis. A normal epididymis was obtained from an orchiectomy specimen. After standard processing for in situ hybridization, tissue sections were hybridized with CFTR gene-probe labelled by incorporation of digoxigenin-dUTP. After hybridization the signal was detected by an alkaline phosphatase-tagged antidigoxigenin antibody. CFTR mRNA was clearly identified in the columnar epithelium of the normal adult epididymis and vas deferens and the signal intensity was greatest in the most proximal regions of the caput epididymis. In contrast, men with genital tract obstructions due to CBAVD or post-vasectomy or post-inflammatory obstructions, had sloughing of the epithelial cells lining the lumen and as a consequence CFTR mRNA expression was lacking. In one subject (post-vasectomy obstruction), some residual caput epididymal epithelium was preserved and CFTR mRNA was detected. The abundant CFTR mRNA expression in the proximal caput of the epididymis and vas deferens under normal conditions strongly favours the hypothesis of an early obstructive process in the pathogenesis of CBAVD. The absent or severely reduced activity of CFTR protein affects the ionic exchange and fluid content within the epididymal lumen and this, in turn, can lead to excessive viscosity of the epididymal fluid, sloughing of epithelial cells expressing CFTR and further reduction in the amount of CFTR activity. As a consequence, variable segments of the epididymis and the vas deferens may be blocked and progressively obliterated. The epididymal lumen obstruction could also sustain the anatomical defects by not allowing testosterone to exert a local action on the mesonephric duct.
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PMID:Expression of the cystic fibrosis transmembrane conductance regulator (CFTR) mRNA in normal and pathological adult human epididymis. 1064 85

Human immunodeficiency virus (HIV) protease inhibitors (PI) may alter lipid metabolism in patients with acquired immunodeficiency syndrome (AIDS). However, the influence of dietary fat on the metabolic effects of PI therapy remains unknown. AKR/J mice were fed high or low fat diets and treated with the PI indinavir (IDV), nelfinavir (NFV), saquinavir (SQV) or amprenavir (APV) by subcutaneous delivery for 2 wk. Serum concentrations of glucose, insulin, triglyceride, free fatty acid, glycerol, pancreatic lipase, bilirubin, alkaline phosphatase, blood urea nitrogen and PI, and interscapular and epididymal fat weights were determined. Some metabolic effects of PI were dependent on diet. IDV- and NFV-treated mice had greater serum glucose concentration and body weight; IDV-treated mice had lower serum insulin; NFV-treated mice had greater interscapular fat mass; and SQV treated mice had lower serum triglyceride concentration than control mice fed the low but not the high fat diet. In contrast, NFV- and IDV-treated mice had greater triglyceride concentration and blood urea nitrogen, and SQV treated mice had greater serum cholesterol than control mice fed the high but not the low fat diet. The serum concentration of SQV was lower in mice fed the high fat compared with the low fat diet. Other effects were not dependent on diet. IDV- and NFV-treated mice had greater fatty acids, and IDV-treated mice had greater pancreatic lipase, bilirubin and alkaline phosphatase than control mice fed either diet. APV treatment had little effect on these serum measurements. Thus, changes in dietary fat can influence some but not all of the effects of PI on metabolism. Furthermore, each PI produces different effects in vivo, indicating that various PI affect distinct metabolic pathways.
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PMID:Dietary fat alters HIV protease inhibitor-induced metabolic changes in mice. 1095 36

In the present work the effects of fasting and refeeding on fat pad weight and alkaline phosphatase activity in the brush border of individual duodenal enterocytes have been evaluated in male Wistar rats with obesity induced by monosodium glutamate (MSG) treatment during the early postnatal period. Neonatal rats were treated subcutaneously with MSG (2 mg/g b.w.) or saline (controls) for 4 days after birth. At 4 months of age, two types of experiments were performed. In the first experiment rats, were submitted to 3 or 6 days lasting food deprivation. In the second experiment the rats were refed for 3 or 6 days ad libitum or restrictedly (60% of pre-fasting intake) after a 6 day-fasting period. Fasting and refeeding influenced the body fat and function of the duodenum in MSG-treated rats differently as compared to the controls. However, alkaline phosphatase activity and the weight of epididymal and retroperitoneal fat depots were significantly increased in MSG obese rats (P<0.001) during all the periods examined. While 3 days of food deprivation resulted in both groups in a similar loss of adipose tissue weight and alkaline phosphatase activity, the decrements of these parameters after 6 days of fasting were lower in obese rats suggesting that their capacity to spare body fat stores was enhanced. After 3 days of ad libitum refeeding, a more marked adaptational increase of food consumption and also a significantly increased alkaline phosphatase activity above the pre-fasting level (P<0.01) was observed in the MSG-treated rats. Consequently, a more rapid body fat restoration was demonstrated in these animals. Refeeding of rats at 60% of the pre-fasting intake level resulted in a significant increase of alkaline phosphatase activity in both the MSG and control group; moreover, as food restriction continued, MSG-treated rats tended to further increase the enzyme activity. Our results revealed that MSG treatment of neonatal rats may significantly change the intestinal functions. Permanently increased alkaline phosphatase activity observed in MSG obese rats during all investigated periods suggests that this functional alteration is probably not a consequence of actual nutritional variation but could be a component of regulatory mechanisms maintaining their obesity at critical values.
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PMID:Effect of fasting and refeeding on duodenal alkaline phosphatase activity in monosodium glutamate obese rats. 1155 Nov 42

beta-Bromo-beta-nitrostyrene is a wide-spectrum biocide most frequently used as a fungicide to combat the formation of slime in paper and pulp mill operations. Toxicity studies were conducted by administering beta-bromo-beta-nitrostyrene (99% pure, trans isomer) to groups of 10 male and 10 female F344/N rats and B6C3F1 mice by gavage, 5 days per week for 4 weeks. Doses of 0, 37, 75, 150, 300, or 600 mg/kg were administered in a corn oil vehicle. The parameters evaluated included hematology, clinical chemistry (rats only), and histopathology. The genetic toxicity of b-bromo-b- nitrostyrene was evaluated in Salmonella typhimurium and in peripheral blood erythrocytes of mice. In addition, the absorption, distribution, metabolism, and excretion of b-bromo-b- nitrostyrene were studied in male F344 rats following intravenous, dermal, or oral administration. In the 4-week study in rats, two males in the 150 mg/kg group, one male and one female in the 300 mg/kg groups, and all rats in the 600 mg/kg groups died or were killed moribund before the end of the study. The mean body weight gains and absolute and relative thymus weights of male and female rats in the 300 mg/kg groups were lower than those of the controls. Hematology evaluations in rats indicated the development of a mild anemia and monocytosis consistent with and likely related to inflammatory and ulcerative lesions that occurred in the gastrointestinal tract. Clinical chemistry evaluations indicated lower alkaline phosphatase activities and serum total protein and albumin concentrations in treated rats than in the controls. Treatment-related lesions in rats were observed in the forestomach, glandular stomach, cecum, nasal passages, and testis. Males were generally affected at lower doses than females. The most prominent lesions were in the forestomach and were characterized by inflammation, hemorrhage, and necrosis in rats dying early. In rats surviving to the end of the study, forestomach lesions included necrosis, ulceration, and regenerative epithelial hyperplasia and hyperkeratosis. Inflammation of the glandular stomach and cecum also occurred in rats dying early. Inflammation and degeneration of the nasal passage in treated rats were attributed to reflux of the irritant chemical in the gavage fluid. Testicular degeneration was seen in rats dying early and was characterized by necrotic germ cells and a decreased number of spermatozoa in the epididymal tubules and by multinucleated syncytial cells in the seminiferous tubules. In the 4-week study in mice, one male in the 300 mg/kg group and all mice in the 600 mg/kg groups died or were killed moribund before the end of the study. No significant changes in final mean body weights or mean body weight gains were observed in males or females. Hematologic changes consistent with inflammatory lesions occurred in male and female mice in the 300 mg/kg groups. Treatment-related lesions in mice occurred in the forestomach, gallbladder, and testis. Forestomach lesions were similar to those described in rats and were only present in male and female mice given doses of 300 mg/kg or greater. At these dose levels, inflammation and degeneration/necrosis of the gallbladder mucosa also occurred in male and female mice, but these lesions were absent in the bile ducts or liver. Testicular degeneration occurred in mice dying early and was similar to that observed in rats. In comparative disposition and metabolism studies in male F344 rats, clear differences were found between the fate of b-bromo- b-nitrostyrene following oral administration and the fate of radiolabeled beta-bromo-beta-nitrostyrene following intravenous or dermal administration. Oral exposure resulted in significant absorption of nonhydrolyzed beta-bromo-beta-nitrostyrene and the formation of parent compound metabolites, primarily 1-phenyl-2-nitroethyl-1-sulfonic acid (PNSA), a product of a sulfation reaction at the alpha carbon. Following dermal exposure, a limited amount of beta-bromo-beta-nitrostyrene entered the systemic circulation (approximately 10% per 24 hours from a 10 mg/cm2 dose) although lower doses were more completely absorbed. Once beta-bromo-beta-nitrostyrene entered the circulation, significant amounts of the dose were hydrolyzed or bound to macromolecules. PNSA was not a major metabolite in dermal or intravenous studies. Regardless of the route of administration, only low levels of radioactive label from beta-bromo-beta-nitrostyrene were retained in tissues following exposure, and most beta-bromo-beta-nitrostyrene metabolites were excreted in the urine and feces within 24 to 48 hours. beta-bromo-beta-nitrostyrene was mutagenic in S. typhimurium strains TA98 and TA100 in the absence of exogenous metabolic activation (S9). No mutagenic activity was observed with S9 in either of these strains, and no mutagenic activity was observed in strains TA97 or TA1535, with or without S9. The frequency of micronucleated normochromatic erythrocytes was significantly increased in the peripheral blood of male mice, but not female mice, following 4 weeks of exposure to beta-bromo-beta-nitrostyrene by corn oil gavage. In summary, under the conditions of these 4-week gavage studies, rats were more sensitive to the toxic and irritant effects of beta-bromo-beta-nitrostyrene than mice, and males were more affected by beta-bromo-beta-nitrostyrene than females. Although the specific cause of the early deaths could not be determined, significant inflammation and necrosis developed in the forestomach of rats and mice, in the glandular stomach and cecum of rats, and in the gallbladder of mice. Similar lesions in the nasal passages of rats were attributed to reflux of gavage materials. The no-observed- adverse-effect level (NOAEL) for histopathologic lesions was 37 mg/kg per day for rats and 150 mg/kg per day for mice.
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PMID:NTP Toxicity Studies of beta-Bromo-beta-Nitrostyrene (CAS No. 7166-19-0) Administered by Gavage to F344/N Rats and B6C3F1 Mice. 1196 39

Serum and seminal biologic substances that are produced either by normal or abnormal tissues of the organism and that can be used to diagnose pathological conditions are usually referred as markers. The aim of this article is to briefly review the most relevant clinical features of the main genital markers in the male dog: alkaline phosphatase (AP), carnitine and canine prostate-specific arginine esterase (CPSE). Carnitine and AP are markers for the presence of epididymal fluid in the ejaculate and their measurement in azoospermic dogs has been used as an indicator of tubular patency of the ductal network. Although AP is not present in high concentrations in the testis, this does not preclude the possibility that testicular cells might secrete some AP. If this were true, AP could also reflect, at least in some degree, germ cell function in this species. Prostate-specific arginine esterase, the major secretory product of the canine prostate, is a known marker of gland secretion in the dog. Tumor markers frequently used in human medicine, such as prostatic acid phosphatase and prostate-specific antigen, are is still controversial in the diagnosis of prostatic carcinoma of the dog. Although further research is necessary to define the exact role of CPSE, it seems to be a promising diagnostic tool in nonneoplasic canine prostatic disorders. Future studies should also address the quantitative relationship among serum and prostatic androgen levels, prostatic androgen-dependent problems and how these are affected by anti-androgen treatment. The aim of this article is to briefly review the most relevant clinical features of three main genital markers of the male dog.
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PMID:Serum and seminal markers in the diagnosis of disorders of the genital tract of the dog: a mini-review. 1201 48

Groups of five male and female Wistar rats were treated by gavage with 0, 0.01, 0.05 or 0.2 mg/kg body weight of the known synthetic estrogen ethinylestradiol for 28-32 days according to a modified enhanced OECD Test Guideline no. 407 in order to investigate which of the current and/or additional parameters would detect effects on the endocrine system reliably and sensitively and to provide data on intra-laboratory variability. Two identical studies (A and B) were run concurrently. The modified enhanced protocol requests the additional determination of triiodothyronine, thyroxine and thyroid-stimulating hormone (TSH), of the stage of the estrous cycle to ensure necropsy of all females in diestrus, of the number and morphology of cauda epididymal spermatozoa, and of additional organ weights (ovaries, uterus, thyroid, and male accessory reproductive organs), and histopathology of additional organs (pituitary, epididymides, coagulation glands, pancreas, and vagina). There were no treatment-related mortalities, clinical signs or changes in behavioral parameters. In male rats, 0.2 mg/kg was the maximum tolerated dose (MTD) resulting in reduced body weight gain. The only treatment-related alteration in hematological parameter was prolonged blood clotting time in high-dose females of both studies. Changes in clinical chemistry observed in study A were elevated alkaline phosphatase activity (high-dose females) and triglyceride levels (mid- and high-dose females and high-dose males). Changes in thyroid hormones and TSH of treated animals showed high variability with no clear dose-dependency, and could not be clearly related to estrogenic activity. In accordance to a suppression of the hypothalamic-pituitary-gonadal axis, decreased relative organ weights of the male accessory reproductive organs were obtained in both studies at the high dose. Corresponding histological changes were degeneration of the testicular germinal epithelium and atrophy of Leydig cells and of all accessory sex glands. Atrophy of the coagulating gland (study A) and seminal vesicles (study B) was also seen at 0.05 mg/kg. A marked increase in relative adrenal weight in male rats, accompanied by decreased vacuolization of zona fasciculata cells observed in both studies at the high dose seems to reflect an activation of the hypothalamic-pituitary-adrenal axis. The male mammary gland was sensitively affected. Increased numbers of small basophilic over large acidophilic cells indicated an estrogen-mediated feminisation and were detected at the low (study A) or mid dose (study B). Co-mitogenic properties of estrogens in rat liver were reflected by increased relative liver weights in females at the mid and high dose of study A and also at the high dose in study B. No treatment-related changes in endocrine organ weights were observed in treated females. Histological changes in the ovaries were increased numbers of apoptotic corpora lutea (from mid dose, study B) and of early stage follicles at the high dose in both studies. Classical direct estrogenic effects on the uterus, i.e. an increased height of luminal and glandular epithelium and increased granulocytic infiltration of the endometrium, were observed even at the low dose in both studies. Uterine findings occurring with a greater variability were dilation, squamous metaplasia of glands and thickened walls. Although females were necropsied in diestrus, as diagnosed by vaginal cytology, typical signs of estrogenic action in the vagina such as keratinization (indicative of estrus in normally cycling rats), mucification (indicative of proestrus), or thickened epithelia were observed in both studies even at the lowest dose. This unexpected discrepancy between vaginal cytology and vaginal and uterine morphology of treated females was considered to be treatment-related as it was not observed in the controls. Studies on liver enzymes that were performed outside the scope of the enhanced protocol showed that ethinylestradiol at 0.2 mg/kg decreased the activity of the sex-specific testosterone-dependent liver enzyme CYP2C11 in male rats. A simulation of doubling group size (to ten animals) by combining both studies did not increase the sensitivity of detection of endocrine-mediated effects above the level already obtained by histopathological examination of groups containing five animals. Only some of the enhancements to the current OECD Test Guideline no. 407 evaluated in this study (additional organs weights and additional histopathological investigations) were helpful in detecting the endocrine-mediated effects of ethinylestradiol, while other enhancements did not contribute towards this aim. Spermatology was completely insensitive at the MTD and measurement of thyroid hormones and TSH did not contribute to increased sensitivity. Vaginal cytology appeared to be an unreliable procedure for estrous cycle staging in estrogen-treated animals. Ongoing investigations, according to the modified version of the enhanced OECD Test Guideline no. 407 protocol, into the interference of ten compounds with the endocrine system by different mechanisms will result in the identification of the most appropriate enhancements.
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PMID:Sensitive detection of the endocrine effects of the estrogen analogue ethinylestradiol using a modified enhanced subacute rat study protocol (OECD Test Guideline no. 407). 1202 82

Testosterone secretion in response to GnRH stimulation and enzymatic activity of semen plasma was evaluated comparatively in rams with or without genital abnormality. Scrota, testes and epididymides of 128 rams between 1.5 and 6 years old from various breeds were examined clinically and ultrasonographically. Bilaterally cryptorchid rams (n = 2), and rams with focal testicular degeneration (n = 3) or unilateral sperm granuloma localized in the caput (n = 3) epididymis or the cauda epididymis (n = 3), diagnosed by either clinical or ultrasonographic examination, were selected for the further investigation of spermatologic parameters, testosterone secretion in response to GnRH stimulation, and enzymatic activity of semen plasma before histopathologic confirmation of lesions. Except for the cryptorchid rams, sperm parameters determined in ejaculates were similar to intact controls (n = 3). GnRH administration increased plasma testosterone levels significantly irrespective of the type of genital pathology (P < 0.01). The testosterone response calculated based on area under the curve following GnRH administration in rams having genital abnormality was not significantly different from the controls. Aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activity in the semen plasma varied between rams, with the lowest mean values in the bilaterally cryptorchid group (P < 0.05). Spermatic granuloma localized either in the caput or cauda of the epididymis was associated with a significant reduction in the semen plasma AST activity compared to controls (P < 0.01). In conclusion, our results indicated that the ability of testicular tissue to secrete testosterone in response to GnRH stimulation in rams with bilateral cryptorchidism, focal testicular degeneration and unilateral sperm granuloma was similar to that of intact controls, and that reduced semen plasma AST activity may have a diagnostic value in the diagnosis of the epididymal obstruction in rams. Focal testicular degeneration did not influence AST, alkaline phosphatase (ALP) and LDH activity in semen plasma.
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PMID:Testosterone secretion and semen plasma enzyme activity in rams with genital pathology stimulated with GnRH. 1204 94

Dibutyl phthalate is a phthalate ester with extensive use in industry in such products as plastic (PVC) piping, various varnishes and lacquers, safety glass, nail polishes, paper coatings, dental materials, pharmaceuticals, and plastic food wrap. Concomitant with this extensive worldwide use is the high potential for human exposure to dibutyl phthalate in the workplace and the home environment through direct sources as well as indirectly, through contamination of water, air, and foodstuffs. Because existing toxicity information was considered inadequate, the effects of exposure to dibutyl phthalate were examined in male and female F344/N rats and B6C3F1 mice in 13-week feed studies. Furthermore, due to concern over the potential for pervasive exposure of humans to dibutyl phthalate, additional perinatal studies examined rats and mice exposed as pups in utero, for the 4 weeks of lactation, and for an additional 4 weeks postweaning. Additional studies examined the effects on rats of combining perinatal and adult subchronic exposure. Due to the recognized biologic activity of this and other phthalates, hepatic peroxisome proliferation during the in utero and lactational phases and testicular toxicity during the perinatal period were also examined. Finally, reproductive assessment by continuous breeding (including crossover mating trials and offspring assessment) and genetic toxicity studies were also conducted. In the maximum perinatal exposure (MPE) determination study in rats, dibutyl phthalate was administered in the diet to dams during gestation and lactation, and to the pups postweaning for four additional weeks, at concentrations of 0, 1,250, 2,500, 5,000, 7,500, 10,000, and 20,000 ppm. Decreased weight gains were noted in dams exposed to 20,000 ppm during gestation and to dams exposed to 10,000 ppm during lactation. The gestation index (number of live pups per breeding female) was significantly lower in the 20,000 ppm group than in the controls, and pup mortality in this group was marked (100% by Day 1 of lactation); however, survival was 89% or greater in all other treatment groups. The mean body weight of pups in the 10,000 ppm group at Day 28 of lactation was approximately 90% of the mean weight of control pups. Pups were weaned onto diets containing dibutyl phthalate at the same concentrations fed to dams. After an additional 4 weeks of dietary administration, final mean body weights of pups in the 10,000 ppm groups were 92% of the control value for males and 95% of the control value for females. Hepatomegaly (increased relative liver weight) was observed in males in all exposed groups and in females receiving 2,500 ppm or greater. No gross lesions were observed at necropsy. Moderate hypospermia of the epididymis was diagnosed in all male rats in the 7,500 and 10,000 ppm groups; mild hypospermia of the epididymis was diagnosed in 2 of 10 males in the 5,000 ppm group. No degeneration of the germinal epithelium was detected in the testis of these rats. Thus, although toxicologically important, the epididymal hypospermia was not considered to be life threatening, and 10,000 ppm was recommended as the MPE concentration for male and female rats. In the subsequent subchronic toxicity study of dibutyl phthalate with perinatal exposure, dams were administered diets containing 0 or the MPE concentration (10,000 ppm) during gestation and lactation, and weaned pups were administered the same diets as their dams received for an additional 4 weeks, until the beginning of the 13-week exposure phase. Male and female rats then received diets containing dibutyl phthalate at concentrations of 0, 2,500, 5,000, 10,000, 20,000, and 40,000 ppm for 13 weeks. No mortality or toxicity was observed in dams during the perinatal phase of the study; however, before pups were culled at 4 days postpartum, the percentage of live pups per litter was 86% to 93% that of the controls. Through weaning, litter weights of exposed pups ranged from 89% to 92% of the control values. Ten control and ten exposed pups per sex were examined at the time of trol and ten exposed pups per sex were examined at the time of weaning; hepatomegaly and markedly increased peroxisomal enzyme activities (approximately 9-fold greater than the control values) were observed in exposed pups. Body weights of the perinatally exposed pups remained lower than those of the controls throughout the 4-week period before the 13-week adult exposures began. During the 13-week adult exposure phase, the final mean body weight of males in the MPE: 0 ppm control group (MPE rats, returned to the base diet for 13 weeks), was 95&percnt; that of the controls. The body weight gain of females in the MPE:0 ppm group was greater than that of the unexposed controls, and the final body weights of these two groups were similar. Body weight gains of rats treated with dibutyl phthalate as adults decreased with increasing exposure concentration; for rats that received the MPE concentration followed by 40,000 ppm for 13 weeks, final body weights were 51&percnt; of the control value for males and 74&percnt; of the control value for females. Hepatomegaly apparently regressed in rats in the MPE:0 ppm groups but was observed in male rats receiving 5,000 ppm or greater and in females receiving 2,500 ppm or greater. In males that received 20,000 ppm as adults, testis and epididymal weights were less than in the controls; males in the 40,000 ppm group also had a lower testis weight than the controls. Results of hematologic analyses conducted at the end of the 13-week exposure period suggested a mild anemia in male rats administered 10,000 ppm or greater as adults and female rats administered 40,000 ppm as adults. Hypocholesterolemia and hypotriglyceridemia were observed in male and female rats at the higher exposure concentrations. Hypotriglyceridemia was detected in females receiving 20,000 or 40,000 ppm and in males receiving 10,000 ppm or greater. Elevations in alkaline phosphatase activities and bile acid concentrations in male and female rats receiving 20,000 or 40,000 ppm as adults were indicative of cholestasis. Microscopic examination revealed hepatocellular cytoplasmic alteration, consistent with glycogen depletion, in male and female rats receiving a concentration of 10,000 ppm or greater. In the liver of rats receiving 40,000 ppm, small, fine, eosinophilic granules were also observed in the cytoplasm of hepatocytes. Ultrastructural examination suggested the presence of increased numbers of peroxisomes. Lipofuscin accumulation was detected in rats that received 10,000 ppm or greater. Consistent with the regression of the hepatomegaly in rats in the MPE:0 and MPE:2,500 ppm groups, peroxisomal enzyme activity was not elevated in these groups. Marked elevations of peroxisomal enzyme activity were detected, however, in males receiving 5,000 ppm or greater and in females receiving 10,000 ppm or greater; at the 40,000 ppm concentration, the highest concentration tested, enzyme activities were approximately 20 fold greater than the control values. Histopathologic examination of the testes revealed degeneration of the germinal epithelium, a mild to moderate focal lesion in rats in the 10,000 and 20,000 ppm groups and a marked, diffuse lesion in all males receiving 40,000 ppm; at 40,000 ppm, an almost complete loss of the germinal epithelium resulted. Testicular zinc concentrations were lower in the 40,000 ppm group than in the controls, a finding consistent with the marked loss of germinal epithelium at this exposure concentration. Spermatogenesis was evaluated in rats in the 0, 2,500, 10,000, and 20,000 ppm groups; rats administered 20,000 ppm had fewer spermatid heads per testis than the unexposed controls, and epididymal spermatozoal concentration was less than that in the MPE:0 ppm group. For comparison with the perinatal subchronic study, a standard 13-week evaluation of the toxicity of dibutyl phthalate in male and female rats was also conducted. In this study, rats received dibutyl phthalate at the same dietary concentrations used in the 13-week exposure phase of the study with perinatal exposure: 0, 2,500, 5,000, 10,000, 20,000, and 40,000 ppm. No deaths occurred in the standard study. Markedly reduced final mean body weights were observed in males and females in the 40,000 ppm groups (45&percnt; and 73&percnt; of control body weights, respectively); final mean body weights of males receiving 10,000 ppm or greater and females receiving 20,000 ppm or greater were lower than those of the controls. Hepatomegaly was observed in males that received 5,000 ppm or greater and in females that received 10,000 ppm or greater. Testis and epididymal weights of males in the 20,000 and 40,000 ppm groups were lower than those of the controls. A minimal anemia was detected in male rats receiving 5,000 ppm or greater. Hypocholesterolemia was observed in male and female rats receiving 20,000 or 40,000 ppm, and hypotriglyceridemia was detected in males in all exposed groups and in females receiving 10,000 ppm or greater. Elevations in alkaline phosphatase activity and bile acid concentration in male and female rats were considered indicative of cholestasis. Morphologic evaluation again confirmed the toxicity of dibutyl phthalate to the liver and testes of rats. Microscopic examination of the liver revealed hepatocellular cytoplasmic alterations, consistent with glycogen depletion, in male and female rats receiving 10,000 ppm or greater. In the liver of rats in the 40,000 ppm groups, small, fine, eosinophilic granules were also observed in the cytoplasm of hepatocytes. Ultrastructural examination suggested the presence of increased numbers of peroxisomes, and peroxisomal enzyme activity was elevated in the livers of male and female rats administered 5,000 ppm or greater; the enzyme activities in the 40,000 ppm groups were approximately 13-fold greater than the control value for males and 32-fold greater than the control value for females. Lipofuscin accumulation was detected in rats receiving 10,000 ppm or greater. Histopathologic examination of the testes revealed degeneration of the germinal epithelium, a mild to marked focal lesion in the 10,000 and 20,000 ppm groups and a marked, diffuse lesion in all males in the 40,000 ppm group; at 40,000 ppm, an almost complete loss of the germinal epithelium resulted. Testicular zinc concentrations were lower in the 20,000 and 40,000 ppm groups than in the controls. Serum testosterone values were also lower at these concentrations than in the controls. Spermatogenesis was evaluated in males in the 0, 2,500, 10,000, and 20,000 ppm groups; at 20,000 ppm, spermatid heads per testis and per gram testis, epididymal spermatozoal motility, and the number of epididymal spermatozoa per gram epididymis were lower than in the controls. All of these findings are consistent with the marked loss of germinal epithelium at these exposure concentrations. In the continuous breeding study, Sprague-Dawley rats received 0, 1,000, 5,000, or 10,000 ppm dibutyl phthalate in feed. Mean body weights of exposed dams at delivery and during lactation generally decreased with increasing exposure concentration. The mean pup weight at birth in the 10,000 ppm group was significantly lower than the control pup weight. The average number of live pups per litter in all exposed groups was lower than in the controls. Crossover mating trials in the F(0) generation revealed no effects on the fertility of male or female rats receiving 10,000 ppm. In contrast to the F(0) rats, mating, pregnancy, and fertility indices of F(1) rats were lower in the 10,000 ppm group than in the controls. Germinal epithelial degeneration of the testes and absence or under development of the epididymides were noted in F(1) males in the 10,000 ppm group. Interstitial cell hyperplasia was noted in 7 of 10 males in the 10,000 ppm group. These effects document the male and female reproductive toxicity of dibutyl phthalate in F(1) rats receiving 10,000 ppm and do not exclude the possibility of developmental toxicity to F2 offspring. In the MPE determination study in mice, dams received 0, 1,250, 2,500, 5,000, 7,500, 10,000, or 20,000 ppm dibutyl phthalate in feed during gestation and lactation; pups were weaned onto the same diets as the dams received and were exposed for an additional 4 weeks. The gestation period was longer in dams that received 2,500 ppm or greater than in the controls, and gestational body weight gain depressions were noted in dams receiving 7,500 ppm or greater. Only 5 of 20 females in the 10,000 ppm group delivered live pups, and none of the 20 females receiving 20,000 ppm delivered live pups. Only one pup in the 10,000 ppm group survived past Lactation Day 1; the number of live pups per litter in the 7,500 ppm group also remained low throughout lactation. No deaths of either male or female pups occurred after weaning. Initial (postweaning) and final body weights of male pups receiving 2,500 ppm or greater were significantly less than those of the control group. The mean body weights of exposed female pups were similar to the control body weight at weaning and remained similar throughout the 4 weeks postweaning. Hepatomegaly was present in male mice in all exposed groups, and the absolute liver weight of males administered 7,500 ppm was greater than that of the controls; although a similar change was apparent in females, no statistical differences between the liver weights of exposed and control females were detected. No treatment-related gross lesions were identified at necropsy, and no histopathologic lesions definitively associated with treatment were observed in male or female mice in the 7,500 ppm groups. The one surviving male pup in the 10,000 ppm group had cytoplasmic alteration in the liver, consistent with peroxisome proliferation. Developmental toxicity and fetal and pup mortality were suggested at concentrations as low as 7,500 ppm. No subchronic toxicity study with prior MPE exposure was conducted with mice, although an MPE concentration of 5,000 ppm was suggested by the data. In a standard 13-week toxicity study, mice received 0, 1,250, 2,500, 5,000, 10,000, or 20,000 ppm dibutyl phthalate in feed. No deaths occurred during this study. Mean body weights and weight gains of male and female mice decreased with increasing exposure concentration, and the decreases were significant for males and females that received 5,000 ppm or greater. Relative liver weights were greater in males and females receiving 5,000 ppm or greater than in the controls. A minimal anemia was suggested in female mice in the 20,000 ppm group. Although no gross lesions were observed at necropsy, microscopic examination revealed hepatocellular cytoplasmic alterations, consistent with glycogen depletion, in male mice receiving 10,000 or 20,000 ppm and female mice receiving 20,000 ppm. Small, fine, eosinophilic granules, consistent with peroxisome proliferation, were also observed in the cytoplasm of hepatocytes in males and females in the 20,000 ppm groups. Lipofuscin accumulation in the liver was detected in mice receiving 10,000 ppm or greater. In a continuous breeding study using Swiss (CD-1®) mice, animals received 0, 300, 3,000, or 10,000 ppm dibutyl phthalate in feed. The fertility index, average number of litters per breeding pair, and average number of live pups per litter in the 10,000 ppm group were lower than in the controls. Crossover mating trials of mice receiving 10,000 ppm revealed effects on dams in the F(0) generation, with a lower fertility index, number of live pups per litter, and pup weight than in the controls. Liver weights were greater in males and females, and the uterine weight was less in exposed dams than in the controls. No other changes were observed at necropsy or on histopathologic examination. These data document the female reproductive toxicity of dibutyl phthalate in F(0) mice. Dibutyl phthalate was not mutagenic in Salmonella typhimurium strain TA98, TA100, TA1535, or TA1537 with or without exogenous metabolic activation but did induce mutations in L5178Y mouse lymphoma cells treated without metabolic activation. In peripheral blood samples obtained from male and female mice at the end of the 13-week study, frequencies of micronucleated normochromatic erythrocytes were similar between exposed and control mice. Together, the studies in rodents suggest that young rodents (in utero and perinatal) respond in a manner qualitatively similar to that of adult rats and mice. Dibutyl phthalate induced toxic effects in rodents as pups in utero and during the lactational phases of development and also affected young adults, as evidenced by fetotoxicity and lethality, body weight gain decrements, increased liver weights, hepatic peroxisome proliferation, testicular toxicity, and female reproductive toxicity. Dibutyl phthalate was lethal to rat fetuses and rat and mouse neonates at dietary concentrations that were not toxic to dams. Otherwise, there was no teratogenic or morphologic evidence that rodent young were uniquely sensitive to the effects of short-term dibutyl phthalate treatment. Synonyms: 1,2-Benzenedicarboxylic acid dibutyl ester; benzene-o-dicarboxylic acid di-n-butyl ester; o-benzenedicarboxylic acid dibutyl ester; butyl phthalate; n-butyl phthalate; DBP; dibutyl 1,2-benzene dicarboxylate; dibutylphthalate; di-n-butylphthalate; di(n-butyl) phthalate; dibutyl-o-phthalate; phthalic acid dibutyl ester. Trade Names: Celluflex DBP; Elaol; Ergoplast FDB; Ersoplast FDA; Genoplast B; Hexaplas M/B; Palatinol C; Polycizer DBP; PX 104; RC Plasticizer DBP; Staflex DBP; Uniflex DBP; Unimoll DB; Witcizer 300; Witicizer 300. (NOTE: These studies were supported in part by funds from the Comprehensive Environmental Response, Compensation, and Liability Act trust fund (Superfund) by an interagency agreement with the Agency for Toxic Substances and Disease Registry, U.S. Public Health Service.)
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PMID:NTP technical report on the toxicity studies of Dibutyl Phthalate (CAS No. 84-74-2) Administered in Feed to F344/N Rats and B6C3F1 Mice. 1220 94

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