Increased testicular steroid concentrations in patients with idiopathic infertility and normal FSH levels

In 10 men with idiopathic infertility, the authors evaluate hypophyso-gonadal axis by measuring the intratesticular concentrations of several steroids in relation with the serum hormonal status. The data are compared with those from men (n = 20) after cerebral death (stage IV coma), taken as a control group. There was no difference between the two groups. The histological studies of the testes revealed no significant differences between control and infertile men both in the development of the interstitial tissue and in the spermatogenic score. Conversely, the testicular concentrations of pregnenolone, dehydroepiandrosterone, progesterone, androstenedione, testosterone, and estradiol were higher in infertile men compared to control. Therefore, it is difficult to evoke a specific parameter involved in that peculiar pathology, but the large amounts of endogenous estradiol may account for the impairment of fertility.

Inhibitory effect of plasma obtained from hypophysectomized and control women on the assay of bioactive luteinizing hormone

The purpose of this study was to determine the effect of components of female plasma on the value of bioactive luteinizing hormone (LH), especially in the presence of low immunological LH value. Using both an immunoradiometric assay (IRMA) and rat Leydig cell bioassay, immunoreactive (I) and bioactive (B) LH were assessed in plasma collected from women during a gonadotrophin releasing hormone (GnRH) test performed on day 7 of a spontaneous cycle. Two modes of response to an acute administration of GnRH were defined: normal production of gonadotrophins (group I) and excessive secretion (group II) associated with a significant difference in the B/I-LH ratio between the two groups. The B/I-LH ratio did not vary with sampling time during the test in either group. The addition of LH-free plasma collected from hypophysectomized women caused a 30% decrease in testosterone production compared to control values (in the presence or absence of hLH standard). A partial restoration of testosterone production was observed if plasma was first treated with PEG 12%. The inhibitory factor(s) was also present in plasma from ovulatory women, even after treatment by an antibody against the entire LH molecule. The effect of normal (A) or low I-LH plasma (B) on testosterone production varied strongly according to the plasma volume added to the bioassay, as well as to plasma treatments. Diethylether treatment caused a 50% decrease in testosterone secretion for plasma B (but not for A) whereas a diminution of the steroidogenesis is observed after a PEG treatment of plasma A (but not for B), suggesting that different inhibitory factors are present in plasmas A and B. Therefore the LH bioactivity measured in the rat Leydig cell assay, in terms of testosterone output, seems to represent a balance between the LH molecule and the presence of inhibitory factors in the plasma.