Perfusion of canine prostatic tissue with [1, 2-3H] 5 alpha-androstane-3 alpha, 17 beta-diol and [4-14C] dihydrotestosterone and the measurement of the isotopic concentrations at the steady state were used to calculate the metabolic dynamics of these steroids by prostatic tissue obtained from normal, castrated or androgen-treated dogs. From the results it was concluded that: Entry of both steroids into the tissue was similar, and no saturation was observed with increasing concentrations of these androgens in the perfusion medium. In contrast, the entry of both steroids was reduced when the perfusion buffer was replaced with diluted plasma. Dihydrotestosterone in prostatic tissue was present in a diffusible form, whereas 3 alpha,17 beta-androstanediol was not. The conversion of 3 alpha, 17 beta-androstanediol to dihydrotestosterone was always higher than the conversion of dihydrotestosterone to 3 alpha, 17 beta-androstanediol; thus, the oxidative pathway was favored. The entry and uptake of both androgens was greatly reduced in those prostates excised from castrated dogs. The uptake of dihydrotestosterone by normal prostatic tissue was 3- to 6-fold higher than the uptake of 3 alpha, 17 beta-androstanediol. However, higher intratissular concentrations of dihydrotestosterone were obtained by increasing the concentration of 3 alpha, 17 beta-androstanediol perfused over that observed by increasing the concentration of dihydrotestosterone perfused. In the hyperplastic tissue, the entry, uptake and metabolism of the two androgens were similar to those observed in the normal gland, but their intratissular concentrations were found to be higher.

Androstane-3,17-diol↗

PubMedDate not supplied

Methicillin-resistant coagulase-negative Staphylococcal osteomyelitis and its relationship to broad-spectrum oral antibiosis in a predominantly diabetic population.

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Ciprofloxacin↗

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Characterization of protein-tyrosine kinase activity in the canine prostate.

Following the measurement of the phosphorylation of the substrate poly(Glu80Na,Tyr20) and the analysis of the alkali-resistant phosphorylation of endogenous proteins, the protein-tyrosine kinase of the canine prostate was partially characterized with regard to its subcellular localization, as well as certain kinetic and molecular properties. This kinase was mainly found in the cytosolic fraction (75%); however, its specific activity was similar to that of the residual enzyme present in the particulate fraction. Conditions for optimal activity of both fractions were determined. Under these conditions, several endogenous phosphoproteins (44-63 kilodaltons upon electrophoresis) were alkali resistant and phosphotyrosine was present in all of the major ones (pp63, pp57, pp52, and pp44). The particulate protein-tyrosine kinase activity was partially solubilized (58%) with 0.5% Triton X-100; this percentage was increased to 85% in the presence of 0.25 M KCl. Upon gel filtration, both cytosolic and particulate kinases showed an apparent molecular mass of 44 kilodaltons; these enzymes also phosphorylated similar major alkali-resistant phosphoproteins. The soluble protein-tyrosine kinase, with a sedimentation coefficient of 4.0S and an isoelectric point of 5.5, could be separated from arginine esterase and prostatic acid phosphatase.

Acid Phosphatase↗