Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Periosteal cells were isolated from tibiae of adult male rats after collagenase treatment. Northern blot analysis of total cytoplasmic RNA extracted from the isolated periosteal cells was positive for expression of genes encoding the osteoblast marker proteins osteocalcin (BGP) and pre-pro-alpha 2(I) chain of type 1 precollagen. The isolated periosteal cells were incubated with 1 nM [3H]testosterone [( 3H]T) for up to 240 minutes and the reaction products separated by high-performance liquid chromatography. [3H]5 alpha-dihydrotestosterone [( 3H]DHT) was not detected in extracts of periosteal cell incubations. In contrast, [3H]DHT was produced in a time-dependent manner by cells from seminal vesicles. These results suggest that testosterone 5 alpha-reductase activity is not expressed by osteoblasts in rat tibial periosteum and that the anabolic effects of androgens in this tissue are not mediated by locally produced DHT.
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PMID:Failure of isolated rat tibial periosteal cells to 5 alpha reduce testosterone to 5 alpha-dihydrotestosterone. 239 4

To evaluate the role of small amounts of DHT in prostate tissue as a stimulus to epithelial cell growth (protein synthesis) we studied tissue from patients given various androgen-blocking drugs prior to transurethral resection of the prostate (TURP) and measured epithelial protein synthesis and DHT in the tissue specimens. We also studied the effects on stromal cell protein synthesis of an antiestrogen, tamoxifen. Test drugs prior to TURP included Megace 160 mg per day, Megace 160 mg per day plus Tamoxifen 40 mg per day, Megace 160 mg a day plus ketoconazole 1200 mg per day and tamoxifen 40 mg/day. The tissue was processed immediately and epithelial and stromal cells separated by digestion of tissue with 0.5% collagenase. After separation, epithelial cells were labeled with either [3H]leucine or L-[35S]methionine. Stromal cells were labelled with [3H]proline. DHT was measured in whole prostate tissue. Megace alone and Megace plus tamoxifen significantly decreased both [3H]leucine incorporation into protein and tissue concentration of DHT; Megace plus ketoconazole significantly decreased L-[35S]methionine incorporation into protein and DHT. Tamoxifen significantly decreased stromal protein synthesis. When the data correlating DHT with epithelial protein synthesis using both labeling techniques were combined, the curves were parallel and a strong correlation was noted between DHT and protein synthesis over a wide range of values (P less than 0.001). These results suggest that in hormone-dependent prostate cancer even small amounts of prostate DHT such as may occur from adrenal androgens following castration may significantly stimulate growth of the tumor epithelial cells. Since tamoxifen decreased stromal protein synthesis, estrogen is likely a significant growth stimulus to the increased stromal mass characteristic of benign prostatic hypertrophy.
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PMID:Effect of antiandrogen and/or antiestrogen blockade on human prostate epithelial and stromal cell protein synthesis. 243 6

Studies were performed to examine the production of progesterone by human placental cells in vitro. Samples of placentas from 22 women at term after spontaneous onset of labor and vaginal delivery were utilized. The tissue was dispersed into isolated cells with the use of collagenase, and suspensions of these cells were incubated with pregnenolone as substrate in the presence or absence of other compounds which may regulate progesterone production. These cell preparations produced progesterone in a dose-related fashion with exogenous pregnenolone. The conversion of pregnenolone to progesterone occurred rapidly, with most of the conversion completed during the first hour of incubation. The conversion was inhibited by dehydroepiandrosterone, estrone, androstenedione, and testosterone (p less than 0.001 in all cases). The inhibitory effect of androstenedione and testosterone was not dependent on aromatization to estrogen. Dihydrotestosterone and 5 alpha-pregnanedione resulted in a significant increase in the amount of progesterone present (p less than 0.001). In preliminary experiments, gonadotropin-releasing hormone, salbutamol, and propranolol were without significant effect in this system. We conclude that this system is a useful model for studying progesterone production by human placental tissue, and that placental progesterone production may be significantly influenced by the presence of other steroid hormones.
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PMID:Steroid modulation of pregnenolone to progesterone conversion by human placental cells in vitro. 629 68

A freeze drying technique was used to form porous three-dimensional collagen matrixes modified by the addition of a variable amount of nano-hydroxyapatite. For chemical cross-linking EDC/NHS were used. Physical cross-linking was achieved by dehydrothermal treatment. Mechanical properties, morphology, dissolution, porosity, density, enzymatic degradation and swelling properties of materials have been studied after cross-linking. The density of scaffolds and its compressive modulus increased with an increasing amount of hydroxyapatite and collagen concentration in the composite scaffold, while the swelling ratio and porosity decreased. The studied scaffolds dissolved slowly in PBS solution. DHT cross-linked collagen matrices showed a much faster degradation rate after exposure to collagenase than the EDC cross-linked samples.
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PMID:Properties and modification of porous 3-D collagen/hydroxyapatite composites. 2306 27