Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ability to form androgen conjugates and the hormone dependency of the conjugating enzymes have been studied in the rat epididymis. Following the in vitro incubation of 3H-testosterone with epididymal slices from intact and castrated rats, the radioactivity recovered was partitioned between water and ether. Examination of the water soluble radioactivity demonstrated the presence of glucuronides and sulfates. The total radioactivity in the conjugate fraction was the same for both intact and castrated animals. However, castrated rats showed a 3-fold increase in the glucuronide fraction with a corresponding decrease in the formation of sulfates. Characterization of the ether soluble radioactivity after solvolysis of the conjugate fraction from castrated animals, showed DHT (17beta-hydroxy-5alpha-androstan-3-one) and 3alpha-diol (5alpha-andro-stane-3alpha, 17beta-diol) to be the main metabolites. After beta-glucuronidase hydrolysis of the same, only 3alpha-diol could be demonstrated at a significant level, although traces of DHT and delta16 compounds were present. Corresponding hydrolysis of the water phase from incubation of epididymis from intact rats, demonstrated a marked quantitative difference. Here approximately 40% of the conjugated aglycones consisted of delta16 compounds, whilst only about 12% was comprised of 3alpha-diol. The preferential conjugation of DHT and 3alpha-diol to a sulfate radical was demonstrated in both intact and castrated rats. Since the conjugated delta16 compounds were detected only in the epididymis from intact animals, it is possible that these are formed by the spermatozoa.
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PMID:Androgen metabolism by rat epididymis. 4. The formation of conjugates. 94 Nov 82

When rabbit sperm were pretreated with media of high ionic strength (380 mOsM), which had previously been shown to facilitate removal of sperm-bound seminal plasma components, and subsequently treated with follicular fluid the acrosome reaction was completed rapidly. Treatment of the sperm with follicular fluid alone yielded a greatly decreased rate of acrosome reaction completion, and treatment with the high-ionic strength medium alone caused no visible alteration to the sperm. These results suggest that removal of the sperm-bound seminal plasma components destabilizes the acrosome and prepares it to undergo the acrosome reaction. This destabilization is virtually completed after a 5-minute preincubation of the sperm in high-ionic strength media. Direct comparison of epididymal and ejaculated sperm indicated that epididymal sperm acrosomes were apparently in the same stabilized condition as ejaculated sperm. The effect of the pretreatment by high-ionic strength media could be partially mimicked by pretreatment of sperm with alpha- or beta-amylase or neuraminidase but not by beta-glucuronidase, lipase, pronase, or trypsin. Comparison of the ability of bovine follicular fluid, rabbit follicular fluid, and rabbit serum to induce the rabbit acrosome reaction showed that bovine follicular fluid was 3 to 4 times more effective than rabbit follicular fluid and that rabbit serum was totally ineffective in producing the acrosome reaction. The data support a physiologic role for follicular fluids in the process of fertilization and indicate that removal of sperm-bound seminal plasma components is a prerequisite to efficient induction of the acrosome reaction.
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PMID:Removal of sperm-bound seminal plasma components as a prerequisite to induction of the rabbit acrosome reaction. 124 42

Oral administration of di(2-ethylhexyl)phthalate (DEHP) at 1000 mg/kg body weight to adult male albino rats maintained on low protein (LP) diet for 15 d resulted in a greater decrease in absolute and relative weights of the testis and in epididymal sperm count than in those rats maintained on a normal protein (NP) diet. A marked increase in the activity of testicular beta-glucuronidase and gamma-glutamyl transpeptidase (GGT) in the LP-fed animals suggested that LP diet enhanced the vulnerability of Sertoli cells towards DEHP. A greater decrease in the activity of testicular acid phosphatase, lactate dehydrogenase isoenzyme-X (LDH-X) and sorbitol dehydrogenase (SDH) in the LP-fed animals occurred in comparison to NP-fed animals. Degeneration of mature germinal cells in the LP-fed animals on exposure to DEHP suggested that LP diets enhance the susceptibility of the testis towards DEHP.
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PMID:The influence of low protein diet on the testicular toxicity of di(2-ethylhexyl)phthalate. 136 64

Effect of styrene (100 or 200 mg/kg body wt/day) for 60 days was observed on testicular enzymes of postnatally maturing rats. A significant decrease in epididymal spermatozoa count was observed only at 200 mg/kg body weight dose. Activities of testicular sorbitol dehydrogenase and acid phosphatase decreased while activities of lactate dehydrogenase, beta-glucuronidase, glucose-6-phosphate dehydrogenase, and gamma-glutamyl transpeptidase significantly increased only in animals exposed to styrene at a dose of 200 mg/kg body weight. The results suggest that exposure to high dose of styrene during developmental period alters the activities of enzymes associated with specific cell type of testis.
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PMID:Effect of styrene on testicular enzymes of growing rat. 145 17

Flutamide, a pure antiandrogen, increases the levels of plasma luteinizing hormone but antagonizes the biological expression of androgen on target organs. Flutamide was administered to rats to study the effect of altered availability of hormones on the functional status of epididymis. The weights of ventral prostate, seminal vesicles and epididymis showed antiandrogenic effects of flutamide. However, increased activity of kidney beta-glucuronidase reflected increased availability of testosterone. The concentrations of protein and DNA along with the activities of acid phosphatase and hyaluronidase decreased in flutamide-treated rats. The activities of acid phosphatase and hyaluronidase in epididymal sperms along with protein concentration increased in flutamide-treated rats. Alteration of epididymal function by treatments affecting lysosomal stability was indicated.
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PMID:Effect of flutamide on the physiological status of epididymis and epididymal sperms. 160

In utero exposure to di(2-ethylhexyl)phthalate (DEHP; 1000 mg/kg body weight) significantly decreased activities of testicular sorbitol dehydrogenase and acid phosphatase and increased gamma-glutamyl transpeptidase, lactate dehydrogenase and beta-glucuronidase activities at early ages. A decrease in the sperm count of the epididymal spermatozoa was also observed in the sexually matured animals of DEHP exposed group. The data suggest that in utero exposure to DEHP may affect the normal development of testes.
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PMID:Effect of in utero exposure to di(2-ethylhexyl)phthalate on rat testes. 181 82

Di-n-butyl phthalate (DBP) was administered to adult male rats by gavage at the doses of 250, 500 and 1000 mg/kg body weight/day for 15 days. A significant decrease in epididymal spermatozoa counts was observed at 500 and 1000 mg/kg doses of DBP. The activity of sorbitol dehydrogenase was found to be significantly decreased while that of lactate dehydrogenase, gamma-glutamyl transpeptidase, beta-glucuronidase, and glucose-6-phosphate dehydrogenase, significantly increased in the animals exposed to 500 and 1000 mg/kg of DBP. Decrease in the activity of acid phosphatase was also observed at all dose levels. Histopathological studies revealed marked degeneration of seminiferous tubules, further confirming testicular toxicity of DBP. The results suggest that testicular atrophy caused by DBP is associated with an alteration in the activities of enzymes related with specific events of spermatogenesis.
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PMID:Testicular toxicity of di-n-butyl phthalate in adult rats: effect on marker enzymes of spermatogenesis. 236 10

Oral administration of di(2-ethylhexyl)phthalate (DEHP) in doses of 250, 500, 1000 and 2000 mg/kg to adult rats for 15 days caused a significant dose dependent decrease in the sperm count of the epididymal spermatozoa. The activity of gamma-glutamyl transpeptidase (gamma GT) and lactate dehydrogenase (LDH) was significantly increased in the animals of the treated groups. An increase in the activity of beta-glucuronidase and decrease in the activity of acid phosphatase was also observed at the highest dose of DEHP. The activity of sorbitol dehydrogenase (SDH) was found to be decreased in the animals exposed to 1000 and 2000 mg/kg of DEHP. These results suggest that DEHP can affect spermatogenesis by altering the activities of the enzymes responsible for the maturation of sperms. The reduced number of sperms may be responsible for the antifertilic effects of DEHP.
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PMID:Effect of di(2-ethylhexyl)phthalate (DEHP) on spermatogenesis in adult rats. 287 65

During transit through the epididymis, spermatozoa acquire fertilizing the cell surface exhibits an altered glycoprotein pattern. Epididymal cells and their secretions contribute to these sperm-surface changes. To examine this process, epithelial cells from rat caput and cauda epididymidis were cultured and examined for the synthesis, processing and secretion of two glycoprotein-modifying enzymes, beta-galactosidase and beta-glucuronidase. Cells were cultured four days, incubated with D-2-[3H] mannose and L-[35S] methionine, and placed in isotope-free media. Levels of both cellular and secreted beta-galactosidase and beta-glucuronidase were determined by immunoprecipitation of cell homogenates or medium, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and scintillation counting of bands. During a 1-h pulse, both caput and cauda cells synthesize two precursor forms of beta-galactosidase (Mr = 84,000 and 87,000), which are processed to the mature (Mr = 63,000) enzyme during a 24-h chase. Caput cells release a high molecular weight (HMW) form (Mr = 90-100,000) and mature beta-galactosidase into the media, but not the Mr = 84-87,000 precursor. On the other hand, cauda cells release mostly mature beta-galactosidase. Ratios of radiolabeled mannose/methionine demonstrate a 7-fold greater mannose content in the cellular precursor of beta-galactosidase than in total protein. Another glycosidase, beta-glucuronidase, is synthesized as a Mr = 78,000-precursor which is processed to the mature Mr = 72,000 form. Medium in which caput and cauda cells were cultured contains both mature enzyme and a Mr = 94,000 form, but no 78,000-precursor form. Ratios of radiolabeled mannose/methionine in the cellular precursor of beta-glucuronidase are 2-fold greater than ratios in the total glycoprotein. Secretion is the major pathway of turnover for several epididymal glycosidases, since more than 50% of the total is secreted/day. These results indicate that cultured epithelial cells from the epididymis synthesize glycosidases and that processing and release differ, depending on the enzyme and the epididymal segment from which the epithelial cells were isolated.
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PMID:Glycosidases in cultured rat epididymal cells: enzyme activity, synthesis and secretion. 309 Nov 1

Seven glycosidases (beta-N-acetylglucosaminidase, alpha-fucosidase, beta-galactosidase, acid alpha-glucosidase, beta-glucuronidase, acid and neutral alpha-mannosidase) were analysed in seminal plasma from the first and second successive ejaculates in normal Ayrshire bulls. In comparison to our previous data the results indicate that beta-N-acetylglucosaminidase, beta-galactosidase and beta-glucuronidase are derived mainly from epididymal secretions, while alpha-fucosidase and particularly neutral alpha-mannosidase originate additionally from the spermatozoan cytoplasmic droplets. The seminal vesicles appear to contribute particularly to the seminal plasma acid alpha-glucosidase and acid alpha-mannosidase activities. The seminal plasma enzymes derived from the epididymis and cytoplasmic droplets were suppressed in semen samples with low sperm density or with high numbers of abnormal spermatozoa. The epididymal and seminal vesicle enzymes could be utilized in assessment of the secretory/functional capacity of these glands.
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PMID:Comparison of glycosidase levels in bovine seminal plasma. 311 30


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