Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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% 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% of the control value for males and 74% 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% and 73% 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

Butyl benzyl phthalate is a plasticizer added to polymers to give flexibility and softness. It is used extensively in polyvinyl chloride and in cellulose plastics, polyvinyl acetate, polysulfides, and polyurethane. Butyl benzyl phthalate was nominated as part of a class study of phthalates. Previous studies of butyl benzyl phthalate by the NTP (1982a) resulted in chemical-related mortality in male rats beginning at about 14 weeks of exposure and, thus, were inadequate for evaluating carcinogenicity in male rats. The companion studies revealed a marginal increase in leukemia in female rats and no evidence of carcinogenicity in B6C3F1 mice. Consequently, the present evaluations were conducted only in F344/N rats. Male and female F344/N rats were given butyl benzyl phthalate (at least 97% pure) in feed for 10 weeks, 26 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, L5178Y mouse lymphoma cells, cultured Chinese hamster ovary cells, mouse bone marrow cells, and Drosophila melanogaster. 10-WEEK MODIFIED MATING STUDY IN RATS: Groups of 15 male F344/N rats were given 0, 300, 2,800, or 25,000 ppm butyl benzyl phthalate (equivalent to average daily doses of approximately 20, 200, or 2,200 mg butyl benzyl phthalate/kg body weight) in feed for 10 weeks. All rats survived to the end of the study. The final mean body weight and body weight gain of the 25,000 ppm group were significantly less than those of the controls. Feed consumption by the 25,000 ppm group was less than that by the controls at the end of the study. A few minimal hematology changes occurred in the 25,000 ppm male rats. There was some evidence of a minimal anemia characterized by a decreased erythrocyte count and increases in mean cell hemoglobin and platelet count. The absolute and relative prostate gland weights of the 25,000 ppm males were significantly less than those of the controls. Degeneration of the seminiferous tubule germinal epithelium was observed in all males from the 25,000 ppm group. The absolute right cauda, right epididymis, and right testis weights of the 25,000 ppm males were significantly less than those of the controls. The epididymal spermatozoal concentrations in 2,800 and 25,000 ppm males were significantly less than that in the controls. Although 10 females mated to 25,000 ppm males were initially found to be sperm positive, none of these females were pregnant at necropsy. The fertility indices of males and females in the 25,000 ppm group were significantly lower than those of the controls. The maternal body weights of females mated to 300 and 2,800 ppm males were similar to those of females mated to control males. There were no significant differences in litter data between the controls and the 300 and 2,800 ppm groups. 26-WEEK STUDY IN RATS: Groups of 15 male F344/N rats were given 0, 300, 900, 2,800, 8,300, or 25,000 ppm butyl benzyl phthalate in feed for 26 weeks. Dietary levels of 300, 900, 2,800, and 8,300 ppm delivered average daily doses of approximately 30, 60, 180, and 550 mg butyl benzyl phthalate/kg body weight. The final mean body weight and body weight gain of the 25,000 ppm males were significantly less than those of the controls. Except for the 25,000 ppm males, feed consumption by all exposed groups was similar to that by the controls. An exposure-related macrocytic responsive anemia was present in the 25,000 ppm group at all time points. Additionally, minimal erythrocyte count decreases occurred sporadically in the 2,800 and 8,300 ppm groups at various time points. Reticulocyte counts were increased on days 60 and 90. Increases in mean cell hemoglobin and mean cell hemoglobin concentrations occurred in the 8,300 and 25,000 ppm rats. The absolute right cauda, right epididymis, and right testis weights and the sperm concentration of 25,000 ppm males were significantly less than those of the controls. The incidences of hypospermia and of atrophy of the seminiferous tubule in the testis and of hypospermia in the epididymis in 25,000 ppm males were significantly greater than those in the in the controls. Degenerative changes of the testis and epididymis in the 25,000 ppm males were qualitatively and quantitatively similar to those observed in males in the 10-week modified mating study. 2-YEAR STUDY IN RATS: Groups of 60 male F344/N rats were given 0, 3,000, 6,000, or 12,000 ppm butyl benzyl phthalate (equivalent to average daily doses of approximately 120, 240, or 500 mg butyl benzyl phthalate/kg body weight), and groups of 60 female F344/N rats were given 0, 6,000, 12,000, or 24,000 ppm butyl benzyl phthalate (equivalent to average daily doses of approximately 300, 600, or 1,200 mg/kg) in feed for 2 years. Survival, Body Weights, and Feed Consumption: Survival of all exposed groups of male and female rats was similar to that of the controls. Mean body weights of the 12,000 ppm males and 24,000 ppm females were less than those of the controls throughout most of the study. Feed consumption by the females exposed to 24,000 ppm was less than that by the controls at the beginning of the study, but was similar to that by the controls by week 6. Hematology and Hormone Assays: In general, hematology changes were sporadic and minor. At 6 months, a minimal decrease in erythrocyte count and an increase in mean cell hemoglobin, similar to that which occurred in the 26-week study, occurred in male rats in the 12,000 ppm group. In female rats, a decreased hematocrit value occurred at 15 months in the 24,000 ppm group. There was also a mild decrease in triiodothyronine concentrations in the 24,000 ppm females at 6 and 15 months and at the end of the study. Pathology Findings: of pancreatic acinar cell adenoma and adenoma or carcinoma (combined) in 12,000 ppm males were significantly greater than those in the controls. The incidences of adenoma and of adenoma or carcinoma (combined) in 12,000 ppm males exceeded the ranges of historical controls from NTP 2-year feed studies. One carcinoma was observed in one 12,000 ppm male, and two adenomas were observed in 24,000 ppm females. At 2 years, the incidence of focal hyperplasia of the pancreatic acinar cell in 12,000 ppm males was significantly greater than that in the controls. At 2 years, transitional epithelial papillomas in the urinary bladder were observed in one control female and in two 24,000 ppm females. The incidence of this neoplasm exceeded the range of historical controls from NTP 2-year feed studies. The incidence of transitional epithelial hyperplasia in 24,000 ppm females was significantly greater than that in the controls. The absolute right kidney weight of 12,000 ppm females and the relative right kidney weights of all exposed groups of males and of 24,000 ppm females were significantly greater than those of the controls at the 15-month interim evaluation. The severities of renal tubule pigmentation in 12,000 ppm males and in 24,000 ppm females were greater than those in the controls at 15 months and 2 years. At 2 years, the incidences of kidney mineralization in 6,000 and 24,000 ppm females were significantly less than that in the controls, and the severity was decreased in exposed females. The incidence of preputial gland adenoma or carcinoma (combined) in 12,000 ppm male rats was significantly less than in the controls, and the incidences occurred with a negative trend. GENETIC TOXICOLOGY: Results from in vitro mutagenicity tests with butyl benzyl phthalate were uniformly negative. No mutagenic response was obtained in any of several strains of Salmonella typhimurium treated with up to 11,550 mg/plate butyl benzyl phthalate, with or without S9 metabolic activation enzymes. Negative results were also obtained in in vitro studies of mammalian cell systems with and without S9. No induction of trifluorothymidine resistance in L5178Y mouse lymphoma cells or sister chromatid exchanges and chromosomal aberrations in cultured Chinese hamster ovary cells were observed. These assays also were conducted with and without S9. No significant increase in sex-linked recessive lethal mutations was observed in germ cells of male Drosophila melanogaster after administration of butyl benzyl phthalate either in feed or by injection. In contrast to the negative results obtained in vitro and in Drosophila, butyl benzyl phthalate gave positive responses in two in vivo studies with mice. Results of a mouse bone marrow sister chromatid exchange test were positive at sample times of 23 and 42 hours, but no confirmatory test was conducted. Chromosomal aberrations were induced in bone marrow cells of male mice sampled 17 hours after intraperitoneal injection of 5,000 mg/kg butyl benzyl phthalate. CONCLUSIONS: Under the conditions of this 2-year feed study, there was some evidence of carcinogenic activity of butyl benzyl phthalate in male F344/N rats based on the increased incidences of pancreatic acinar cell adenoma and of acinar cell adenoma or carcinoma (combined). There was equivocal evidence of carcinogenic activity of butyl benzyl phthalate in female 344/N rats based on the marginally increased incidences of pancreatic acinar cell adenoma and of transitional epithelial papilloma of the urinary bladder. Exposure of rats to butyl benzyl phthalate in feed for 2 years resulted in focal hyperplasia in the pancreas in male rats and in transitional epithelial hyperplasia in the urinary bladder of female rats. Synonyms: A13-14777; BBP; 1,2-benzenedicarboxylic acid butyl phenylmethyl ester (9CI); benzyl n-butyl phthalate; n-butyl benzyl phthalate; butyl phenylmethyl 1,2-benzenedicarboxylate; NCI-C54375; phthalic acid benzyl butyl ester (8CI) Trade names: Palatinol BB; Santicizer 160; Sicol 160; Unimoll BB
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PMID:NTP Toxicology and Carcinogenesis Studies of Butyl Benzyl Phthalate (CAS No. 85-68-7) in F344/N Rats (Feed Studies). 1258 18

In order to comparatively assess the systemic toxicity and sperm parameters, nine phthalate diesters, including di(2-ethylhexyl) phthalate (DEHP), di(n-butyl) phthalate (DBP), di-n-octyl phthalate (DnOP), diethyl phthalate (DEP), butylbenzyl phthalate (BBP), dimethyl phthalate (DMP), di-isodecyl phthalate (DIDP), diundecyl phthalate (DUP), and di-isononyl phthalate (DINP), and five phthalate monoesters, including mono(2-ethylhexyl) phthalate (MEHP), monobutyl phthalate (MBuP), monobenzyl phthalate (MBeP), monoethyl phthalate (MEP), monomethyl phthalate (MMP), and phthalic acid (PA) were administered orally to Sprague-Dawley male rats at 250 (phthalate monoesters and PA) or 500 mg/kg body weight (bw)/d (phthalate diesters) for 4 wk. Liver weights were significantly increased in g roups treated with DEHP, DBP, BBP, DIDP, DINP, MEHP, and MBuP compared to the control. Testes weights were significantly reduced only in DEHP, DBP, and MEHP-treated groups compared to the control. Significant decreases in red blood cell (RBC) and hematocrit (Ht) levels were observed in DEHP-treated rats, whereas significant increases in mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and platelet (PLT) levels were found in the DEHP-treated group. Hemoglobin (Hb) level was reduced only in the DMP group. Similar to effects on testis and epididymal weights, DEHP and MEHP significantly reduced sperm numbers and motility. In particular, DnOP, DBP, BBP, MEP, MBuP, DUP, DINP, and MBeP significantly lowered the sperm counts and sperm motility of epididymal sperm, detected by a change in the sperm motion parameters. The strongest to the weakest adverse effects for sperm motility were as follows: DEHP > DBP > DnOP > DUP > DIDP > BBP among diesters and MBuP > MEP > MEHP among monoesters, respectively. These results suggest that the adverse effects of phthalate esters (PEs) on sperm parameters in male rats are greater with phthalate diesters than monoesters, which may be useful for the risk assessment of phthalates.
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PMID:Comparative toxicological evaluation of phthalate diesters and metabolites in Sprague-Dawley male rats for risk assessment. 2007 17