Endocrine profile in patients with chronic renal failure under zinc replacement.

The plasma levels of androstenedione (A), testosterone (T), dihydrotestosterone (DHT), follicle stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) were studied in 15 men (aged 24-50 years) with chronic renal failure under periodic peritoneal dialysis, before and after 50 mg of elemental zinc (Zn) orally, twice a day for three weeks. Before treatment, they were divided into three groups: group I, plasma A above normal and PRL less than 100 ng/ml; group II, low or normal A levels with PRL less than 100 ng/ml; and group III, normal or high A levels with PRL greater than 100 ng/ml. After oral Zn, plasma FSH, LH, and PRL were unchanged in all groups; however, in groups I and II plasma A was within normal T and DHT rose significantly, the A/(T+DHT) ratio decreased to normal, and the T/DHT ratio rose above normal. In group III plasma androgens remained low and androgen ratios were unchanged. Oral Zn seems to improve the conversion of A to T and also uncovered the possibility that plasma PRL levels greater than 100 ng/ml might cause a blockade in the 5 alfa-reductase.