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)

Age-related hypertrophy of adipose tissue has been associated with a significant decrease in the number of angiotensin II receptors. The aim of this study was to investigate the characteristics of angiotensin II receptors in hypertrophic adipose tissue in animal obesity model using rats postnatally treated with monosodium glutamate. Angiotensin II is known to induce hypertrophy in several tissues of the cardiovascular system and might do the same in fat tissue. The expression and binding properties of angiotensin II AT(1) receptors in epididymal fat tissue of adult rats were studied using membrane-binding, RT-PCR, and immunoblotting. The amount of AT(1) receptor mRNA did not differ significantly between obese and control rats. Despite that glutamate-treated rats displayed approximately 4-times more AT(1) receptor immunoreactive protein content in fat tissue cell membranes than the controls did. In contrast, binding experiments showed a significant (40.3 +/- 6.2 %) decrease of (125)I-Sar(1)-Ile(8)-angiotensin II-binding to fat tissue cell membranes in obese rats compared to controls. In conclusion, the present study provides evidence for the low binding properties associated with an accumulation of AT(1) receptor protein in cell membranes of the fat tissue of rats with glutamate-induced obesity. Discrepancies among angiotensin II-binding, AT(1) receptor protein, and AT(1) receptor mRNA levels indicate a possible defect in the receptor protein, which remains to be identified. The results obtained support a role of angiotensin II and AT(1) receptors in the pathogenesis of obesity.
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PMID:Elevated AT1 receptor protein but lower angiotensin II-binding in adipose tissue of rats with monosodium glutamate-induced obesity. 1175 55

Transgenic male mice carrying inactive mutations of the receptor tyrosine kinase c-ros lack the caput epididymidis initial segment and are infertile because sperm volume regulation is compromised. Complementary DNA arrays were used to detect differences in gene expression in the caput epididymidis of heterozygous fertile and homozygous infertile males. The glutamate transporter excitatory amino acid carrier 1 (EAAC1) was expressed in all epididymal regions with high expression in the initial segment and cauda epididymidis. Homozygous knockout mice did not express EAAC1 messenger RNA (mRNA) in the caput but they did express the gene in the corpus and cauda. Immunohistochemical staining for EAAC1 confirmed regional mRNA expression and demonstrated an adluminal location on stereocilia/microvilli of principal cells. The glutamate transporter-associated protein (GTRAP) 3-18 was detected in all epididymal regions independent of genotype, but a highly abundant novel transcript of 4.2 kilobases was found only in the initial segment of heterozygous c-ros mice. High-performance liquid chromatography measurement of glutamate revealed a significantly higher content in the proximal caput of infertile mice than fertile mice, and tissue glutamate content decreased distally in both genotypes. Because glutamate is used as an osmolyte in somatic cells, the lack of EAAC1 reported here may disturb normal osmolyte balance in the proximal epididymal lumen and compromise sperm maturation, in particular the development of sperm volume regulatory mechanisms.
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PMID:Lack of glutamate transporter EAAC1 in the epididymis of infertile c-ros receptor tyrosine-kinase deficient mice. 1239 22

Transgenic male mice bearing inactive mutations of the receptor tyrosine kinase c-ros lack the initial segment of the epididymis and are infertile. Several techniques were applied to determine differences in gene expression in the epididymal caput of heterozygous fertile (HET) and infertile homozygous knockout (KO) males that may explain the infertility. Complementary DNA arrays, gene chips, Northern and Western blots, and immunohistochemistry indicated that some proteins were downregulated, including the initial segment/proximal caput-specific genes c-ros, cystatin-related epididymal-spermatogenic (CRES), and lipocalin mouse epididymal protein 17 (MEP17), whereas other caput-enriched genes (glutathione peroxidase 5, a disintegrin and metalloproteinase [ADAM7], bone morphogenetic proteins 7 and 8a, A-raf, CCAAT/enhancer binding protein beta, PEA3) were unchanged. Genes normally absent from the initial segment (gamma-glutamyltranspeptidase, prostaglandin D2 synthetase, alkaline phosphatase) were expressed in the undifferentiated proximal caput of the KO. More distally, lipocalin 2 (24p3), CRISP1 (formerly MEP7), PEBP (MEP9), and mE-RABP (MEP10) were unchanged in expression. Immunohistochemistry and Western blots confirmed the absence of CRES in epididymal tissue and fluid and the continued presence of CRES in spermatozoa of the KO mouse. The glutamate transporters EAAC1 (EAAT3) and EAAT5 were downregulated and upregulated, respectively. The genes of over 70 transporters, channels, and pores were detected in the caput epididymidis, but in the KO, only three were downregulated and six upregulated. The changes in these genes could affect sperm function by modifying the composition of epididymal fluid and explain the infertility of the KO males. These genes may be targets for a posttesticular contraceptive.
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PMID:Gene and protein expression in the epididymis of infertile c-ros receptor tyrosine kinase-deficient mice. 1289 Jul 34

Volume regulation by spermatozoa has been demonstrated to be crucial in both mice and men for transport in the female tract. In order to determine the nature of osmolytes used by spermatozoa, they were released from the cauda epididymis of fertile c-ros heterozygous mice into incubation medium of uterine osmolality (representing an osmotic challenge), containing increasing concentrations of compounds that are major epididymal fluid components and known osmolytes in somatic cells. This should nullify the concentration gradients for osmolytes that mediate volume regulation, prevent osmolyte efflux, and lead to swelling. Of the osmolytes tested, K(+) caused the most rapid and extensive volume increases; glutamate, taurine, L-carnitine, and myo-inositol also were effective, but glycerophosphocholine was not. Such effects were not observed in cauda sperm from the infertile knockout mice, demonstrating a defect in normal volume regulation. K(+) concentrations in cauda epididymal fluid were 21 mM higher in the knockout than the heterozygous mice, but no differences were found in caudal fluid glutamate, carnitine, or myo-inositol. The carnitine content of cauda sperm from knockout males was not different from that of fertile males, but lower amounts of glutamate and inositol were found that could explain the poor volume regulation. In heterozygous mice, cauda but not caput sperm responded to the K(+) channel blocker quinine by swelling, demonstrating development of volume regulation during epididymal transit, whereas knockout cauda sperm showed no response, as with the osmolytes. Major epididymal secretions could serve as osmolytes in murine spermatozoa for volume regulation in response to physiological osmotic challenge in the normal fertile mice; the reduced sperm content of inositol and glutamate in the c-ros knockout mice might reflect maturational abnormalities in volume regulation.
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PMID:Effects of putative epididymal osmolytes on sperm volume regulation of fertile and infertile c-ros transgenic Mice. 1476 7

To investigate the relationship between development of obesity and the small intestinal functions two experimental models of male Wistar rats were used in the present work: 1) early postnatally overfed rats, nursed from birth to weaning in small litters (SL, 4 pups/nest), and 2) neonatally monosodium glutamate treated rats (MSG 2 mg/g b.w. administered s.c. for 4 days after birth) submitted to the same early nutritional manipulation. After weaning, all animals had free access to a standard pellet diet and at 40 and 80 days of age their body weight, body fat content and food consumption as well as changes of the brush-border-bound duodenal and jejunal alkaline phosphatase (AP) activity were compared with parameters of the offsprings raised under normal feeding conditions (NL, 8 pups/nest). At 40 and 80 days of age the postnatally overfed pups from SL nests became heavier, displayed a significantly increased epididymal plus retroperitoneal fat pad weight (P<0.01) and significantly higher AP activity in both segments of the small intestine (P<0.01) in comparison with rats nursed in NL nests, although their mean daily food intake did not differ from that of non-obese rats during the postweaning periods examined. In contrast, the same treatment of MSG rats had only a small effect on late appearance of obesity, i.e. in early postnatally overfed and normally fed MSG rats a similar pattern of body weight, food intake, adiposity and AP activity was found after weaning. The effect of MSG-treatment was also accompanied by the appearance of normophagia, hypophagia and stunted growth on day 40 and day 80, respectively. Moreover, the size of fat depots and the increase of brush-border-bound AP activity in MSG rats belonging to the SL and NL groups was quantitatively similar to the values size of these parameters observed in SL obese rats subjected to early postnatal overnutrition. These results indicate that postnatal nutritional experience (overnutrition) may represent a predisposing factor in control rats from small litters for the development of obesity in later life. Permanently increased small intestinal AP activity observed after weaning in both models of obesity when hyperphagia is not present suggest that these functional changes and associated alterations in food digestion could be a component of regulatory mechanisms contributing to the maintenance of their elevated body fat weight.
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PMID:Obesity and changes of alkaline phosphatase activity in the small intestine of 40- and 80-day-old rats subjected to early postnatal overfeeding or monosodium glutamate. 1504 54

Exercise training is often recommended in prevention and treatment of obesity. The present study was designed to compare the effects of intermittent and continuous exercise on weight loss and carcass composition in obese rats. Obese male Wistar rats (monosodium glutamate [MSG] administration, 4 mg/g of body weight every other day from birth to 14 days old) were used. After drug administration, the rats were separated into three groups: MSG-SED (sedentary), MSG-CONT (continuous, swimming, 45 min/day, 5 days/week, with and overload of 5% body weight for 12 weeks) and MSG-INT (intermittent, 15 s swimming intermitted by 15 s rest, during 45 min, 5 days/week, with and overload of 15% body weight for 12 weeks). Rats of the same age and strain, administered with saline were used as control (SAL), and subdivided into three groups: SAL-SED, SAL-CONT and SAL-INT. The animals were evaluated at the 10 weeks of training and 8 weeks of its interruption. MSG rats showed higher carcass fat as well as weight and cell size in epididymal adipose tissue than SAL rats, indicting the efficacy of the drug in producing obesity. Intermittent training protocol led to a reduction in blood lactate accumulation during acute exercise and both protocols reduced body weight gain during the experiment in MSG rats. After 8 weeks of training interruption no differences were observed among groups in the examined parameters. Only intermittent exercise training improved aerobic fitness but both protocols were similarly efficient in determining weight loss. However, the effects were transitory, since they disappeared after detraining.
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PMID:[Continuous and intermittent exercise: effects of training and detraining on body fat in obese rats]. 1533 57

This study examines the concentrations of carnitine, glutamate and myo-inositol in fluid and spermatozoa from six epididymal regions. Samples were taken from six post-pubertal boars, and the sperm concentration, the protein concentration in epididymal fluid and the concentrations of carnitine, myo-inositol and glutamate in the epididymal fluid and spermatozoa were analysed. In epididymal fluid the concentration of myo-inositol decreased in a proximo-distal direction, whereas intraluminal concentrations of L-carnitine and L-glutamate increased distally. As changes in the concentration of these solutes did not parallel changes in sperm concentration, this may reflect secretion or absorption of theses solutes. The sperm content of inositol fell as they moved from the distal caput whereas glutamate content increased from the distal caput to more distal regions and carnitine content remained unchanged during epididymal transit. This is the first attempt to elucidate the changes in the content of glutamate and inositol in epididymal spermatozoa of mammals and in the fluid from different epididymal regions of boars.
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PMID:Concentrations of carnitine, glutamate and myo-inositol in epididymal fluid and spermatozoa from boars. 1648 63

Glutamine synthetase (GS) is the only enzyme that can synthesize glutamine, but it also functions to detoxify glutamate and ammonia. Organs with high cellular concentrations of GS appear to function primarily to remove glutamate or ammonia, whereas those with a low cellular concentration appear to primarily produce glutamine. To validate this apparent dichotomy and to clarify its regulation, we determined the GS concentrations in 18 organs of the mouse. There was a >100-fold difference in GS mRNA, protein, and enzyme-activity levels among organs, whereas there was only a 20-fold difference in the GS protein:mRNA ratio, suggesting extensive transcriptional and posttranscriptional regulation. In contrast, only small differences in the GS enzyme activity : protein ratio were found, indicating that posttranslational regulation is of minor importance. The cellular concentration of GS was determined by relating the relative differences in cellular GS concentration, detected using image analysis of immunohistochemically stained tissue sections, to the biochemical data. There was a >1000-fold difference in cellular concentrations of GS between GS-positive cells in different organs, and cellular concentrations were up to 20x higher in subpopulations of cells within organs than in whole organs. GS activity was highest in pericentral hepatocytes (approximately 485 micromol.g(-1).min-(1), followed in descending order by epithelial cells in the epididymal head, Leydig cells in the testicular interstitium, epithelial cells of the uterine tube, acid-producing parietal cells in the stomach, epithelial cells of the S3 segment of the proximal convoluted tubule of the kidney, astrocytes of the central nervous tissue, and adipose tissue. GS activity in muscle amounted to only 0.4 micromol.g(-1).min(-1). Our findings confirmed the postulated dichotomy between cellular concentration and GS function.
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PMID:Cellular concentrations of glutamine synthetase in murine organs. 1660 3

1. The testis of the ram secretes considerable amounts of amino acids (200mumoles/day) into the fluid collected from the efferent ducts. The principal amino acid in this testicular fluid is glutamate, which is present in concentrations about eight times those in testicular lymph or in blood from the internal spermatic vein. 2. The concentration of glutamate in seminal plasma from the tail of the epididymis is about ten times that in testicular fluid, and, though glutamate is the major amino acid in ejaculated seminal plasma, its concentration is less than in epididymal plasma. 3. After the intravenous infusion of [U-(14)C]glucose, labelled glutamate was found in the testicular fluid. Radioactivity was also detected in alanine, glycine, serine plus glutamine and aspartate. Alanine had the highest specific activity, about 50% of the specific activity of blood glucose. 4. When [U-(14)C]glutamate was infused, the specific activity of glutamate in testicular fluid was only about 2% that in the blood plasma. 5. Testicular and ejaculated ram spermatozoa oxidized both [U-(14)C]glutamate and [U-(14)C]leucine to a small extent, but neither substrate altered the respiration from endogenous levels. 6. No radioactivity was detected in testicular spermatozoal protein after incubation with [U-(14)C]glutamate or [U-(14)C]leucine. Small amounts of radioactivity were detected in protein from ejaculated ram spermatozoa after incubation with [U-(14)C]glutamate. 7. The carbon of [U-(14)C]glucose was incorporated into amino acids by testicular spermatozoa; most of the radioactivity occurred in glutamate.
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PMID:Amino acids in ram testicular fluid and semen and their metabolism by spermatozoa. 1674 31

Early investigators reported the occurrence of unidentified protein factors in biological fluids that may regulate sperm motility essential for fertility potential. This study reports for the first time purification of a forward motility stimulating protein (FMSF-I), to apparent homogeneity, from a biological fluid (buffalo blood serum) and its characterization. FMSF-I is the major motility protein of buffalo serum: a rich source of the factor. FMSF showed high protein specificity and affinity for activating forward motility of goat cauda epididymal spermatozoa. The motility promoter at 0.5 microM level showed maximal activity when nearly 60%-70% of spermatozoa expressed forward motility. It is a 66 kDa monomeric acidic protein rich in aspartate, glutamate, and leucine with isoelectric point of 3.7. FMSF: a Mg2+ -dependent protein binds to concanavalin A-agarose and the glycoprotein nature of FMSF has been confirmed by PAS staining. The factor lost activity completely when treated with alpha-mannosidase showing that the sugar part of the protein is essential for its biological activity. FMSF has no species specificity for its motility-activating potential. Sperm surface has specific receptors of FMSF, which is strongly immunogenic. The factor is present in testis and epididymis although liver is its richest source. Motility promoting efficacy of FMSF is markedly higher than the well-known non-protein motility activators: theophylline and bicarbonate or their combination. FMSF is a physiological activator of sperm motility and as a slaughterhouse byproduct it has potentiality for solving some of the problems of animal breeding, conservation of endangered species, and human infertility: a global social problem.
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PMID:Identification and characterization of a sperm motility promoting glycoprotein from buffalo blood serum. 1688 95


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