[Studies on the pituitary-testicular axis in male patients with chronic renal failure with different glomerular filtration rate (author's transl)].

In 32 male patients with chronic renal failure (age 22-60 yrs), of which 17 showed a creatinine clearance below 20 ml/min (group I) and 15 above 20 ml/min (group II), plasma levels of total testosterone (T) and total oestradiol-17beta (E2) were measured before and after stimulation with HCG i.m. LH and FSH were evaluated before and after stimulation with LH-RH i.v. Additionally, testosterone binding capacity (TeBG), free testosterone fraction (%FT) and "absolute" free testosterone (AFT) were determined. In comparison with normal persons T was clearly reduced before and after HCG in group I, whereas in group II it was reduced only after HCG. E2 showed normal basal values in both groups, but in group I it was decreased after HCG. Except for LH values after stimulation in group II, both groups showed increased LH and FSH levels before and after LH-RH in comparison with controls. TeBG and %FT did not show any changes in either group, whereas AFT was reduced in both of them. Comparing the results of group II and I we found in the latter decreased values for T before and after HCG and for E2 after HCG as well as decreased values for AFT, whereas LH and FSH before and after LH-RH were increased. There existed no significant correlation between any of the parameters T, AFT and E2 on the one hand and LH and FSH on the other hand. Significant correlations are found between creatinine clearance and T, AFT, LH and FSH. The results indicate a primary defect of the testis which gradually depends on the degree of renal insufficiency, but with well working feed-back mechanism. The possibility of an additional central regulation defect in the sense of a relative autonomy of the hypophyseal gonadotropin secretion is discussed.