Biomedical subjects

C Scorticati

Publications and source records attributed to C Scorticati.

At least 37 records · Page 2Linked to original sources

PubMed1981

Testosterone, dihydrotestosterone, and zinc concentrations in human testis and epididymis.

Tissue testosterone, dihydrotestosterone, and zinc concentrations have been determined in testis and epididymis of 13 patients with carcinoma of the prostate, 1 patient with carcinoma of the penis, and 3 patients with carcinoma of the prostate on estrogens. The 13 patients not receiving estrogens had the following testicular levels: testosterone, of 529 +/- 63.1 ng/g (mean +/- SE); dihydrotestosterone, 23.7 +/- 2.58 ng/g; and zinc 62.2 +/- 7.6 micrograms/g. The epididymal levels were as follows: testosterone, 40.6 +/- 3.4 ng/g; dihydrotestosterone, 20.5 +/- 2.36 ng/g; and zinc, 67.2 +/- 11.1 micrograms/g. Patients on estrogen therapy showed much lower androgen values in the two organs but zinc was not changed significantly. Concentrations of androgens were not significantly different in the epididymal fractions of caput, corpus, and cauda. In testis, there was a positive correlation between zinc and androgens contents, while the opposite was suggested by the data in the epididymis. Even though these patients were not normal, there was no evidence of testicular or epididymal disturbances.

Aged↗

PubMed1980

Uptake and metabolism of androgen by the human epididymis in vitro.

Uptake and metabolism of [3H]testosterone, mainly to 5 alpha-dihydrotestosterone (5 alpha-DHT and 5 alpha-androstanediol were higher in the caput than in the cauda epididymidis in vitro. The metabolites represented 57, 49 and 47% of the total radioactivity in the caput, corpus and cauda epididymidis, respectively; subcellular distributions of the metabolites in each segment showed 67% of total radioactivity in cytosol and 18% in the nuclei. In both fractions, the amount of 5 alpha-DHT was greater than that of androstanediol while the reverse was true for the mitochondria and microsomes. The distribution of 5 alpha-reductase activity in subcellular fractions was similar to that of the microsomal marker enzyme NADPH: cytochrome C reductase, whilst 3 alpha-hydroxysteroid dehydrogenase was found mainly in the cytosol. Maximal 5 alpha-reductase activity was at pH 5.3, apparent Km values in the microsomal and nuclear fractions were 1.65 +/- 0.7 and 1.75 +/- 0.36 x 10(-6) M respectively, and the Vmax in these preparations was 5.28 +/- 1.19 and 3.1 +/- 0.52 pmol/mg protein/min, respectively. The activity of 5 alpha-reductase was inhibited by Zn2+, Cu2+, Ba2+ and Cd2+ and by epitestosterone, progesterone and 4-androstene-3-one 17 beta-carboxylic acid.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMedDate not supplied

Induced hypoprolactinemia and testicular steroidogenesis in man.

The effects of short-term hypoprolactinemia on the pituitary-gonadal axis were evaluated in a group of patients with untreated prostatic carcinoma. Each patient was studied prior to and during 7-day oral administrations of bromocriptine (2.5 mg q.i.d.). Serum LH, prolactin (PRL), androst-4-ene-3,17 dione (androstenedione), testosterone, and 5 alpha-androstane-3 alpha, 17 beta-diol (5 alpha-Diol) levels, as well as intra-testicular testosterone, dihydrotestosterone (DHT), 5 alpha-Diol and zinc (Zn) concentrations, were determined. Daily administration of bromocriptine caused a marked suppression of serum PRL (mean +/- SEM, 23.8 +/- 2.5 vs. 6.4 +/- 1.0 ng/ml) without concomitant changes in serum LH levels (mean +/- SEM, 8.3 +/- 1.6 vs. 8.9 +/- 2.1 ng/ml). Hypoprolactinemia induced a significant decrease (P less than 0.05) in the mean peripheral testosterone levels; but 5 alpha-Diol and androstenedione remained unchanged. However, in testicular tissues, bromocriptine treatment resulted in significant increases in mean concentrations of total androgens (P less than 0.001), testosterone (P less than 0.001) and DHT (P less than 0.02). Testicular levels of 5 alpha-Diol were not significantly altered. There was no change in Zn levels in basal conditions and during bromocriptine administration. These results indicate that short-term suppression of serum PRL levels in man affects basal testicular function without altering serum LH. However, a direct action of bromocriptine on the human gonad cannot be excluded.

Aged↗

PubMedDate not supplied

The effect of in vitro androgen stimulation upon androgen metabolism and trophic parameters in cultured human epididymis.

Previous results obtained with a model system of human epididymal tubules maintained in organ culture suggested that androgenic stimulation of this tissue resulted in responses similar to those obtained in epididymides of experimental animals under physiological conditions, as well as in other human androgen-dependent tissues. In this instance we have explored the possible influence of androgens on the activity of the androgen-converting enzymes 5 alpha-reductase and 17 beta-dehydrogenase. Activity of the former enzyme increases significantly during the culture period but no differences were found among the cultured groups, regardless of the addition of androgen. On the other hand, the activity of 17 beta-dehydrogenase was unchanged in all the experimental conditions tested. The co-culture of the tissue with explants of human testis was without effect. More than 85% of the activity of both enzymes was found localized in a fraction enriched in epithelial cells. Histological observation of the cultured tissues showed a marked disorganization of the pseudostratified epithelium in the absence of androgen while the inclusion of DHT in the media partially prevented these changes. We conclude that, under the conditions employed in these experiments, the activity of the enzymes studied is not influenced by androgens.

17-Hydroxysteroid Dehydrogenases↗

PubMedDate not supplied