Adrenal Glands in Lactating Rats Bearing Hypothalamic Lesions.

It has been previously reported (Y o k o y am a and 0 t a, 1959a and b) that the lesions placed in the periventricular and the medial hypothalamic areas in lactating rats impaired oxytocin secretion selectively. Considerable amount of milk was obtained by oxytocin replacement in these rats, although the amount of milk was less than that obtained in normal lactating animals. There has been a considerable body of evidence indicating the view that the adrenal corticoids were one of the critical factors for maintaining lactation in rats (C o w i e, 1961). G a l e, T a 1 ei s n i k, Friedman and McCann (1961) demonstrated direct relation between the adrenal size and lactational performance in lactating rats bearing lesions in median eminence. An attempt was made to associate histological changes in adrenal glands with those in lactational performance in lactating rats bearing hypothalamic lesions, since changes in adrenal glands were presumed to reflect those in the secretory level of the gland.