Basal levels of pituitary ACTH and plasma corticosterone after complete or frontal cuts around medial basal hypothalamus.

Plasma corticosterone level and corticotropin (ACTH) content of the anterior pituitary (AP) were measured after various cuts around the medial basal hypothalamus (MBH). Seven to eight days after placing a complete cut around MBH there was no change in plasma corticosterone or ACTH content of AP; the slight rise in ACTH concentration was offset by the decreased weight of AP. Twenty eight days after a frontal cut there was no change in plasma corticosterone and in bioactive or immunoreactive ACTH concentration of AP.