Stimulation of serum inhibin concentrations by gonadotropin-releasing hormone in @entity1 with XXXX .

@entity1 @entity251 @entity1176 @entity12107
Inhibin is a gonadal hormone thought to be important in FSH regulation. We investigated the effects of the hypogonadotropic state and subsequent @entity1176 -induced increases in gonadotropin levels on inhibin secretion. Serum levels of inhibin, LH, FSH, and @entity251 (T) as well as sperm concentrations were measured in 5 @entity1 with @entity12107 ( @entity12107 ) before (baseline) and during 8 weeks of @entity1176 therapy (5 micrograms, sc, every 2 h). Baseline and peak inhibin levels were compared to those in a group of 19 normal @entity1 . Before @entity1176 administration, the mean serum inhibin level was significantly lower in the @entity12107 @entity1 than in the normal @entity1 [166 +/- 56 (+/- SE) vs. 588 +/- 30 U/L; P less than 0.001]. Serum inhibin levels rose after 1 week of @entity1176 therapy (P less than 0.05) and remained higher than the baseline level thereafter. The mean peak inhibin level during @entity1176 administration was lower than the mean value in normal @entity1 (485 +/- 166 vs. 588 +/- 30 U/L; P less than 0.05). Serum LH and FSH levels rose promptly to the midnormal range or slightly above it. Serum T levels did not significantly increase until 4-5 weeks of @entity1176 administration and remained in the low normal range. All @entity12107 @entity1 were azoospermic throughout the study. These data are consistent with the hypothesis that inhibin is produced by the testis under gonadotropin control. They also suggest the possibility of defective Sertoli and Leydig cell function in @entity1 with @entity12107 , since the men's serum inhibin and T levels did not rise to the same extent as did their normalized serum gonadotropin levels during @entity1176 administration.
