Angiotensin II antiserum decreases luteinizing hormone-releasing hormone in the median eminence and preoptic aea of the rat

Ovariectomized female rats were sacrificed 3 h after intracerebroventricular microijnjection of normal rabbit serum (NRS), specific antiserum against angiotensin II (AB-AII) or atrial natriuretic factor (AB-ANF). AB-AII decreased plasma LH by 50% and LH-RH content by 70% in the median eminence and medial preoptic area, respectively, but did not change plasma FSH when compared to animals which receivede NRS. There was no difference in these parameters when the animals were injected with AB-ANF or NRS.These results indicate that endogenous AII plays a physiological role in LH release acting directly or indirectly through LH-RH neurons of the median eminence and medial peroptic area