THE ANTIREPRODUCTIVE ROLE OF CORTICOTROPIN-RELEASING HORMONE AND INTERLEUKIN-1 IN THE FEMALE RHESUS-MONKEY

Interleukin-1 alpha (IL-1 alpha) exerts numerous neuroendocrinological and immunological actions. In the ovariectomized (OVX) monkey, intrac erebroventricular (icv) infusion of IL-1 alpha stimulates the hypothal amo-pituitary-adrenal (HPA) axis and inhibits pulsatile LH and FSH sec retion. This inhibitory effect of IL-1 alpha on the gonadotropins is p revented by coadministration of corticotropin releasing hormone (CRN) and vasopressin (AVP) antagonists, suggesting a role of these two HPA neuropeptides. In order to understand the central mechanisms by which <<stress>> interrupts the menstrual cycle, we have also investigated t he modulatory role of estradiol. When early follicular phase estradiol concentrations are reproduced, there was a complete prevention of HPA activation and of the consequent inhibition of gonadotropin by IL-1 a lpha. The mechanisms regulating this unexpected action remain to be el ucidated. In contrast, in the presence of late follicular phase estrad iol concentr ations, the HPA response to IL-1 alpha is restored, but t here is a stimulation of LH release. These data demonstrate interactio ns between the adrenal and gonadal endocrine axes, and highlight the r ole of estradiol in modulating these effects.