Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In in vitro tests with lysosomes isolated from the liver and kidneys of castrated rats of both sexes the action of testosterone and beta-estradiol in concentrations of 3.76.10(-4)M on the activity of beta-glucosidase, beta-galactosidase and acid phosphatase was investigated. Testosterone is shown to reduce the total and free activity of the membrane-bound enzymes and to increase the release from the matrix lysosomes. Estradiol proved less active than is testosteron. The renal lysosomes in vitro are more sensitive to the action of sex hormones than are hepatic lysosomes. In the interaction of testosterone and estradiol with lysosomal membranes a sex specificity was revealed.
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PMID:[The effects of testosterone and estradiol on the activity of lysosomal enzymes in rat liver and kidneys]. 9 95

The ventricular myocardium was studied in A/J mice and in Sprague-Dawley rats. In male mice, the ventricles were slightly larger and the specific activities of the lysosomal hydrolases, beta-glucuronidase, hexosaminidase, beta-galactosidase, and arylsulphatase, and the inner mitochondrial enzyme cytochrome c oxidase were substantially higher than in female mice. Orchiectomy abolished this sex difference. Testosterone administration induced myocardial hypertrophy and accretion of RNA and protein without altering the DNA, and substantial increases in the activities of the lysosomal hydrolases and cytochrome c oxidase. However, the mitochondrial membrane enzyme monoamine oxidase was unaffected by sex, orchiectomy, and testosterone administration. Heart lysosomes from male mice showed a smaller structure-linked latency of the lysosomal enzymes and a greater fragility of the lysosomal membrane to osmotic and mechanical stress than those from female mice. This sex difference was also abolished by orchiectomy and restored by testosterone replacement. Similar sex differences were observed in the rat with respect to heart size, acid hydrolase activities, and lysosomal enzyme latency and membrane stability. These findings indicate that endogenous androgens regulate myocardial cell growth, the activity of enzymes associated with lysosomes and the inner mitochondrial membrane, and some physiochemical properties of lysosomes.
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PMID:Testosterone-mediated sexual dimorphism of the rodent heart. Ventricular lysosomes, mitochondria, and cell growth are modulated by androgens. 704 2

There is a concern that chemicals in our environment are affecting human health by disrupting normal endocrine function. Much of the concern has focused on chemicals that can interact directly with steroid hormone receptors. We have used a yeast-based assay to assess chemical interactions with the estrogen, androgen, and progesterone receptors. The yeast transformants used in this study contained the human estrogen, androgen, or progesterone receptor along with the appropriate steroid responsive elements upstream of the beta-galactosidase reporter gene. Chemicals were added to yeast cultures in doses ranging from 10(-12) to 10(-4) M and following incubation, the yeasts were then lysed and assayed for beta-galactosidase activity. Diethylstilbesterol and 17-beta estradiol were most active in the estrogen receptor assay, followed by the phytoestrogen, coumestrol. p-Nonylphenol and bisphenol A were approximately 5000- and 15,000-fold less active, respectively, than estradiol. Methoxychlor, DDT and its metabolites, o,p'-DDD, and o,p'-DDE ranged in potency from 5 to 24 X 10(6) less potent than estradiol. Testosterone and dihydrotestosterone were most potent in the androgen receptor assay, followed by estradiol and progesterone. p,p'-DDE was approximately 10(6)-fold less potent than testosterone. None of the industrial chemicals tested interacted with the progesterone receptor. These data demonstrate the utility of using yeast-based receptor assays for detecting chemical interaction with steroid receptors and these assays should serve as a useful component of an in vitro-in vivo strategy to assess the effects of chemicals on endocrine function.
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PMID:Evaluation of chemicals with endocrine modulating activity in a yeast-based steroid hormone receptor gene transcription assay. 907 9

Recently, we have identified a gene encoding a LuxR-type factor, TeiR (Testosterone-inducible Regulator), which positively regulates steroid degradation in Comamonas testosteroni. Herein, we demonstrate that TeiR interacts in vivo with steroid catabolic gene promoters. The presence of testosterone induces a significant TeiR protein increase at the early logarithmic phase of growth. Interestingly, it is not until the early stationary phase where the activation of a steroid-inducible gene promoter is observed, indicating that testosterone might not be the true inductor of the steroid degradation pathway. In addition, beta-galactosidase expression driven by a testosterone-inducible promoter is prematurely activated in cells cultured in medium supplemented with ethyl acetate extracts obtained from the early stationary phase cell-free supernatants of C. testosteroni grown in presence of testosterone. Complementation experiments of C. testosteroni wild type performed with teiR deletion constructs indicate that extra-copies of deleted-TeiR exert a dominant negative effect on the wild-type TeiR protein. While, when C. testosteroni teiR mutants were used to carry out complementation assays only the full length gene can overcome the teiR mutant phenotype. Altogether these findings indicate that TeiR regulates steroid catabolic genes interacting with their promoters and suggest that this interaction requires the presence of a testosterone-derived metabolite to induce the system.
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PMID:Regulation of testosterone degradation in Comamonas testosteroni. 1885 46