S. Gulizia

HYDROTESTOLACTONE LOWERS SERUM OESTRADIOL AND PRL LEVELS IN NORMAL MEN: EVIDENCE OF A ROLE OF OESTRADIOL IN PRL SECRETION*

The effect on serum PRL levels of lowering serum oestradiol (E2) concentration by short‐term administration of an aromatase activity inhibitor, hydrotestolactone (HT), was studied in six healthy male subjects. After HT administration serum E2 levels decreased from 68 ± 5±8 to 26 ± 2±5 pmol/1 (mean ± SE, P < 0±05). These E2 changes were accompanied by a significant decrease in mean 2‐h PRL levels from 11±2 ± 2±1 to 6±5 ± 1±6 ng/ml mean ± SE, P < 0±05). The evaluation of individual percentage change from basal concentrations showed a varying decrease in all subjects. These findings suggest that under physiological conditions E2 may be one of the factors which control blood PRL concentrations in men.

Abnormal germinal exfoliation in semen of hypogonadotrophic patients during a hCG treatment.

Abnormale Keimzellenabschilferung im Samen hypogonadotroper Patienten während HCG‐Therapie

Effect of cyproterone acetate acutely administered on the pituitary-testicular axis.

The effect of cyproterone acetate (CA) on the pituitary-testicular axis was studied in 6 healthy men. A dose of 300 mg of CA was administered orally in the early morning, after 3 h blood samples were collected using a multiple sample technique. Testosterone (T) levels were decreased by CA in all subjects (p 0.01), LH in all (p less than 0.01) but one whereas 17-hydroxyprogesterone did not show any significant variation. In vitro, using an equilibrium dialysis, CA displaced T from plasma-binding proteins in males at 37 degrees C. The role of testosterone-binding globulin on the effects of CA on the pituitary-testicular axis remains to be clarified.

Some Critical Considerations on the Use of the Nomifensine Test in the Hyperprolactinaemic Syndrome

Nomifensine has recently been proposed as a dynamic test to discriminate tumoral from functional hyperprolactinaemia. In the present study, this test was performed in 9 subjects with radiological signs of sellar alteration and in 6 with no signs of pituitary lesion. Adopting the criterion reported in the previous study, the test was considered positive in 2 subjects of the first group and in 2 subjects of the second group. Therefore, our study indicates that the ability of this test to discriminate subjects with tumorous or non-tumorous hyperprolactinaemia still appears debatable.

Kinetics of steroid responsiveness to hCG during chronic inhibition of testicular function by GnRH analogue

The effect of daily injections of D-Ser-(TBU)6-LRH-EA10 (GnRH analogue (GnRH-A) 100 micrograms sc) on serum testosterone (T), 17 alpha-hydroxyprogesterone (17OHP) and oestradiol-17 beta (E2) was studied in 4 men. During GnRH-A therapy T, 17OHP and E2 were markedly decreased by the end of the second month. Continuous long-term administration of GnRh-A inhibited testicular function. To test whether the biosynthetic pathway was affected by the regimen, a bolus of 2000 U hCG was given to each subject after 10 months of therapy. Evaluation of the kinetics of steroid responsiveness showed a significant release of T in response to the trophic stimulus, with little or no elevation of serum 17OHP and E2. The response seen in these treated men appeared similar to that found in hypogonadotrophic men and prepubertal boys.