Similarity of plasma LH release in androgenized and normal rats following electrochemical stimulation of the basal forebrain.

Because of conflicting data in the literature, the ovulatory response to electrochemical stimulation (ECS) of the medial septal-preoptic complex was measured in pentobarbital-treated normal proestrous and androgenized female rets. Increasing the stimulus strength increases the incidence of ovulation in normal but not in androgenized rats. However, since the ovaries of androgenized rats are relatively insensitive to LH, whereas pituitary responsiveness to LH-releasing factor is normal, the response to ECS was further evaluated in terms of plasma LH. Immunoassayable plasma LH was significantly elevated 30 min after stimulation. Peak LH levels occurred 90 min after stimulation and were returning toward baseline after 120 min. There was no difference in mean plasma LH values in normal and androgenized rats at any time. Stimulation of the diagonal band of Broca, medial septum or medial preoptic area elicited similar plasma LH responses in both groups. These results indicate that the responsiveness of the medial septal-preoptic complex to ECS is not deleteriously affected by neonatal androgen treatment.