Adrenal glands alter the concentration of oestradiol-17β and its receptor in the uterus of ovariectomized ewes

Abstract

ABSTRACT To investigate the effects of adrenal hormones on oestrogen activity in the uterus, ovariectomized ewes were either adrenalectomized, administered glucocorticoid-like preparations (CORT), or remained as controls. The adrenalectomized ewes were maintained with a corticoid-replacement therapy and monitored daily for plasma glucose and Na+/K+ concentrations. Blood samples were collected from all ewes at 15-min intervals for 4 h and assayed for LH and FSH. The adrenalectomized ewes were killed 9 days after adrenalectomy, while the CORT ewes were killed after 3 weeks of drug therapy. The control ewes were killed simultaneously with the CORT ewes. Uterine tissues were homogenized and the numbers of oestradiol receptors and tissue concentrations of oestradiol-17β were measured. The adrenalectomized ewes had significantly higher concentrations of cytosolic oestrogen receptors in the uterus than did the control ewes, which had significantly higher concentrations than the CORT ewes (0·95±0·06, 0·76 ± 0·02 and 0·60±0·02 (s.e.m.) μmol/kg protein respectively). The concentrations of oestradiol-17β measured in uterine tissues were significantly lower in adrenalectomized and CORT ewes than in control ewes (37·4±5·5, 61·7±25·7 and 135·5 ± 12·8 pmol/kg respectively). There were no significant differences between any groups in the peripheral concentrations of LH or FSH. These results indicate that the adrenal gland affects the concentrations of both oestrogen and its receptor in the uterus of ovariectomized ewes, probably by different mechanisms. These effects are not mediated by gonadotrophins. J. Endocr. (1988) 118, 375–380