Metabolism of progesterone by human leukocytes

Role of granulation tissue and fibroblasts in gingival testosterone metabolism in the rat in vitro

The metabolism of testosterone by experimental granulation tissue, fibroblasts and the oral mucosa of rats of both sexes was studied. The experimental granulation tissue was produced by implanting viscose-cellulose sponges beneath the dorsal skin of female and male rats for 21 days. The granuloma capsules, fibroblasts in the sponges and the oral mucosae were homogenated. Mitochondrial, microsomal and soluble fractions were incubated with [4-14C]testosterone and NADPH for 30 min at pH 7.4 and 37 degrees C. The metabolites were identified with column and TLC and radioautography and quantified with liquid scintillation counting. The experimental granulation tissue and fibroblasts of both sexes showed less activity in metabolizing testosterone than the gingival tissue. The tissues were shown to contain 3 alpha-, 3 beta- and 17 beta-hydroxysteroid dehydrogenase and 5 alpha- and 5 beta-steroid hydrogenase activities. The activities of the enzymes in the oral mucosae were higher than in the experimental granulation tissue and fibroblasts.

In vitro metabolism of steroid hormones in the liver and in blood cells of male rainbow trout (Salmo gairdneri Richardson)

Male rainbow trout show high plasma androgen levels beginning with the period of full spermatogenesis until the end of spermiation. The difficulties in explaining the steroid levels in regard to the concomitant changes of the plasma GTH concentrations prompted investigations into whether the steroid demand may be met in part by extragonadal steroid metabolism. The results of in vitro experiments with liver tissue fit into the concept of an interrenal-liver-gonad axis of androgen production, since increased amounts of C-19 steroids were detected in the media after incubation of hepatic tissue with cortisol. 17 beta-Hydroxysteroid dehydrogenase and hydroxysteroid glucuronyltransferase activities were shown to be associated with blood cells of mature males. The fact that unidentified products from incubations with 17 beta-estradiol, testosterone, and 17 alpha-hydroxyprogesterone were also found suggests that other steroid metabolizing enzymes are also associated with blood cells. The possibility is discussed that, assuming the blood cell activities are relevant in vivo, a production of potent androgens or the formation of water soluble steroid derivatives could proceed in the blood (e.g., 11-ketoandrostenedione----11-ketotestosterone; testosterone----testosterone glucuronide), possibly affecting the organism's steroid balance.

Metabolism of progesterone by healthy and inflamed human gingiva in vitro

[4-14C]Progesterone was incubated with homogenate and mitochondrial, microsomal and soluble fraction preparations of healthy and inflamed gingiva from human subjects of both sexes. The subcellular preparations were supplemented with an NADPH-regenerating system and incubated for 2 h at pH 7.4 and 37 degrees C. The metabolites were identified by column, multiple TLC and radioautography and quantified with liquid scintillation counting. In inflamed tissue the metabolic activity was higher than in healthy gingiva. On the basis of the identified metabolites it can be concluded that the human gingiva of both sexes contains marked 3 alpha-, 3 beta- and 20 alpha-hydroxysteroid dehydrogenase, delta 4-5 alpha- and delta 4-5 beta-steroid hydrogenase activities, and less 20 beta-hydroxysteroid dehydrogenase activity.