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)

Each epididymis of control and swainsonine-fed rats (5 micrograms/ml drinking water) was divided into 5 segments, and tissue, spermatozoa and sperm-free supernatants were prepared from each segment. When levels of 3 lysosomal glycosidases and total protein were determined, the proximal cauda contained the greatest concentration of glycosidase. The specific-activity profile for beta-glucuronidase and beta-galactosidase was similar in swainsonine-fed and control rats. However, the concentration of alpha-D-mannosidase in tissue of all segments was significantly greater in swainsonine-fed rats than in age-matched controls. Enzyme activity for alpha-D-mannosidase after swainsonine treatment was significantly greater in spermatozoa from the caput, than in spermatozoa from the corpus and the cauda epididymidis. Since the alpha-D-mannosidase activity was optimal at pH 4.5 and studies with highly specific antibody to lysosomal alpha-D-mannosidase immunoprecipitated all of the alpha-D-mannosidase present in detergent extracts of epididymal tissue, spermatozoa, and sperm-free supernatant, the enzyme studied is of lysosomal origin.
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PMID:Effect of swainsonine on rat epididymal glycosidases. 314 32

Daily oral administration of acrylonitrile (10 mg/kg body weight) to mice for a period of 60 days caused a significant decrease in the activity of testicular sorbitol dehydrogenase and acid phosphatase, and an increase in that of lactate dehydrogenase and beta-glucuronidase. Histopathological studies revealed degeneration of the seminiferous tubules. A decrease in the sperm counts of the epididymal spermatozoa was also observed in the animals of the acrylonitrile-exposed group. These observations suggest that acrylonitrile may affect the male reproductive function by causing testicular injury.
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PMID:Testicular effects of acrylonitrile in mice. 338 48

The influence of cyproterone acetate (CA) (0.1 mg/mouse/day) on the epididymis and male fertility was analyzed in a long-term study in the Swiss albino cc strain. CA inhibits epididymal function in all segments as measured by organ weights, protein content and beta-glucuronidase activity. This antiandrogen also suppresses male fertility. It is important to note that the low dose of CA, used in this study, does not affect spermatogenesis. The effects of CA on epididymis and fertility are reversible and the magnitude of recovery or the period (in days) required for a significant recovery after the discontinuation of CA were seemingly directly proportional to the duration of antiandrogen treatment.
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PMID:A long-term study of the epididymal- and fertility-suppressing effects of cyproterone acetate in the mouse. 644 92

The influence of previous sexual experience and subsequent differential housing on the epididymis and fertility index was studied for male Swiss albino cc mice. Among animals with previous sexual experience those having a high epididymal beta-glucuronidase activity showed a high fertility index and vice versa. The reproductive potential of animals without previous sexual experience was reduced by housing in high-density groups and in isolation. The results show that previous sexual experience, individual housing and group volume may influence the reproductive potential of male mice.
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PMID:Impact of socio-sexual conditions on the epididymis and fertility in the male mouse. 729 42

This study demonstrates that beta-glucuronidase from rat preputial glands binds with high affinity to spermatozoa from the cauda epididymis. The binding was calcium-independent and was inhibited by mannose-6-phosphate, but not by other phosphorylated or non-phosphorylated sugars. Binding was also inhibited by alpha-mannosidase from Dictyostelium discoideum, an enzyme known to have mannose-6-phosphate as the ligand. From solubilized sperm membranes, a protein of > 200 kDa and one of 45 kDa, were absorbed to a column of D. discoideum enzyme and to a phosphomannan column respectively, and eluted with mannose-6-phosphate. According to histochemical observations at the light and the electron microscopic level, gold particles coated with the enzyme became bound to the external surface of the plasmalemma in the acrosomal region of caudal spermatozoa. Similar labelling was observed using gold particles coated with antibodies against the rat 300 kDa phosphomannosyl receptor. The existence of phosphomannosyl receptors on the sperm plasma membrane, and our previous demonstration of the presence of affinity sites for epididymal beta-galactosidase on these gametes which is inhibited by phosphofructosyl derivatives, suggest strongly that maturing spermatozoa could be a target for glycosidases secreted into the lumen of the cauda epididymis, which then become bound to these cells via different ligand-receptor systems.
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PMID:Phosphomannosyl receptors on the surface of spermatozoa from the cauda epididymis of the rat. 755 73

The epithelium of caput and cauda epididymidis of the rat was studied with transmission electron microscopy (TEM) and freeze-fracture techniques. In thin sections of both zones, the tissue consisted mainly of tall columnar cells (principal cells) with long sterocilia. Clusters of small membrane-bound vesicles were located in the lumen between or immediately over the stereocilia. Freeze-fracture replicas also displayed groups of smooth-surface vesicles in the same location. Membrane-bound vesicles isolated from the lumen of the rat epididymis were studied by TEM. In thin sections, some of them contained an electron dense material and others looked empty. In addition, the hydrolases: beta-galactosidase, N-acetyl-glycosaminidase, alpha-mannosidase, aryl-sulfatase and beta-glucuronidase were detectable in pellets of vesicles treated with Triton X-100. The results presented here indicate the presence of membrane-bound vesicles observed by two different methodologies in the rat epididymal fluid and demonstrate five glycosidases in their content.
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PMID:Morphological and enzymatic study of membrane-bound vesicles from the lumen of the rat epididymis. 775 84

1. The toxic manifestations of dermally applied hexachlorocyclohexane (50 mg or 100 mg kg-1 body weight day-1, 5 days in a week for 120 days) on testes and sperm of rat have been investigated. 2. The results indicate that exposure of HCH through the dermal route could lead to an alteration in the activities of marker testicular enzymes viz. sorbitol dehydrogenase (SDH), glucose-6-P-dehydrogenase (G6PDH), gamma-glutamyl transpeptidase (gamma-GT) and beta-glucuronidase (beta Gluc.) associated with specific cell types. 3. Significant quantities of HCH and its isomers accumulated in testes as well as sperm of treated rats. 4. HCH exposure also led to a decrease in serum testosterone levels, epididymal sperm count, sperm motility and an increase in the percentage of abnormal sperm. 5. These observations indicate the possibility of adverse effects of HCH on the male reproductive functions of men exposed dermally to this pesticide in industry or during spraying in the field.
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PMID:Effect of dermal application of hexachlorocyclohexane (HCH) on male reproductive system of rat. 851 23

The expression and androgen regulation of beta-glucuronidase molecular forms were examined in mouse epididymis, liver, and kidney. Two-dimensional polyacrylamide gel electrophoresis performed under nondenaturing conditions showed that, compared to liver and kidney, which contain four microsomal (M1-M4) and a major lysosomal (L) form of beta-glucuronidase, the epididymis revealed regional differences and tissue specificity in the expression of the various molecular forms of the enzyme. Only the lysosomal form (pI 5.4-6.1) is present in the caput epididymidis while the corpus/cauda contains the lysosomal form, the free X form (pI 5.9-6.3) and the four microsomal forms (X form complexed with egasyn). Mutant mice that lack egasyn have no microsomal forms in the distal epididymis. In epididymal fluid, the lysosomal form is found throughout the epididymis, whereas the X form appears only in the corpus/cauda epididymidis. Sodium dodecyl Sulfate (SDS)-gel electrophoresis and western blot analysis of immunoprecipitated beta-glucuronidase revealed only one band corresponding to the L form (apparent molecular weight 74 kDa) in the caput epididymidis and two bands in the corpus/cauda (apparent molecular weights 73 and 75 kDa), corresponding to L and X forms, respectively. Castration of mice led to the suppression of the regional differences in the appearance of X and M forms in the epididymis. Testosterone supplementation to castrated mice restored the characteristic electrophoretic pattern of beta-glucuronidase in the caput epididymidis. In the liver and kidney, castration has no effect on the expression of the molecular forms, whereas androgen treatment induced the X form in the kidney. Histochemical localization of beta-glucuronidase confirmed the region specificity seen in the epididymis and in addition revealed cell specificity in the expression of beta-glucuronidase. These results indicate that beta-glucuronidase shows tissue specificity and, in the case of the epididymis, region and cell specificity. In addition, the enzyme in the different tissues responds differentially to androgens.
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PMID:Androgen regulation of molecular forms of beta-D-glucuronidase in the mouse epididymis: comparison with liver and kidney. 879 10

Glycosidases secreted by the epididymis become bound to the surface of spermatozoa during their transit through the epididymal duct. They are believed to play a role in mammalian fertilization. In the present report, we demonstrate that beta-glucuronidase binds to the surface of ejaculated human spermatozoa with high affinity and in a saturable manner. The binding is Ca(2+)-independent, inhibited by either mannose-6-phosphate, phosphomannan fragments from the yeast Hansenula holstii and alpha-mannosidase from the Dictyostelium discoideum, suggesting that phosphomannosyl receptors are involved in the recognition of the enzyme. The catalytic site of the enzyme is not involved in the binding. The localization of the beta-glucuronidase binding-sites is restricted to the surface of the sperm head. These results suggest that the spermatozoa could be the target for glycosidases present in the seminal plasma.
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PMID:Affinity sites for beta-glucuronidase on the surface of human spermatozoa. 902 Oct 45

Spermatozoa released from the seminiferous tubules are terminally differentiated cells with no known synthetic activity. Their components are synthesized in the spermatogenic cells during spermatogenesis. In this study, we report the characterization and immunolocalization of beta-glucuronidase in mouse testicular germ cells and spermatozoa. The enzyme is an exoglycohydrolase with dual localization, being present in lysosomes and endoplasmic reticulum of several mouse and rat tissues. The purified germ cell preparations (spermatocytes, round spermatids, and condensed/elongated spermatids) when assayed for beta-glucuronidase activity showed that the spermatocytes contained five times more enzyme activity per cell than the spermatids. Polyacrylamide gel electrophoresis, carried out under native and denaturing conditions, demonstrated that the germ cells express only the lysosomal form of the enzyme (pI 5.5-6.0) with a subunit molecular mass of 74 kDa. Immunocytochemical studies revealed a positive reaction in the Golgi membranes, Golgi-associated vesicles, and lysosomes of late spermatocytes (pachytene spermatocytes) and a stage-specific localization during spermiogenesis. The forming or formed acrosome of the elongated spermatids (stages 9-16) and epididymal spermatozoa was highly immunopositive. Comparison of immunoprecipitation curves and kinetic properties of the enzyme present in spermatocytes and spermatozoa revealed no major differences. Taken together, our results demonstrate that beta-glucuronidase activities present in the lysosomes of spermatocytes and the sperm acrosome are kinetically and immunologically similar.
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PMID:Characterization and immunolocalization of beta-D-glucuronidase in mouse testicular germ cells and spermatozoa. 1004 47


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