DEHYDROEPIANDROSTERONE-SULFATE AND ANOVULATION INCREASE SERUM INHIBINAND AFFECT FOLLICULAR FUNCTION DURING ADMINISTRATION OF GONADOTROPINS

To test the hypothesis that testosterone (T) derived from circulating dehydroepiandrosterone sulfate (DS) or produced in excess within the a novulatory ovary is a follicular regulator capable of stimulating inhi bin secretion, DS and inhibin were determined by RIA in residual serum samples from in vitro fertilization cycles and analyzed along with ot her parameters using analysis of variance and stepwise multiple linear regression after log transformation of the RIA data. It was predicted that the serum concentration of inhibin would be higher in women with anovulation than in normal subjects and that the serum inhibin concen tration would have a positive regression coefficient on the serum DS c oncentration. The serum concentrations of inhibin (P < 0.01) and estra diol (P < 0.001) on the day of hCG treatment were higher in women with anovulation than in normal subjects, as was the number of oocytes ret rieved (P < 0.001). The FSH and LH doses (both P < 0.005) and age (P < 0.001) were significantly lower, and the average duration of gonadotr opin therapy was 1 day shorter (P < 0.001) in anovulatory patients. Th ere was no significant difference in serum DS (P > 0.2).Regression ana lysis showed that serum inhibin was positively related to the number o f oocytes (P < 0.001) and serum DS (P = 0.05), with an increase in ano vulatory subjects (P < 0.025). The duration of treatment with gonadotr opins was related positively to the patient's age (P < 0.001) and nega tively to serum DS (P < 0.025), with a decrease in anovulatory subject s (P < 0.025). The number of oocytes obtained was negatively related t o age (P < 0.001) and positively to serum DS (P < 0.005). These data a re consistent with a stimulatory effect of follicular T derived from e ither circulating DS or the anovulatory ovary, which affects the secre tion of inhibin, the duration of gonadotropin treatment, and the numbe r of oocytes retrieved.