Effects of adrenalectomy on the stress-induced changes in ovarian sympathetic tone in the rat

A 3-wk period of stress promotes the development of ovarian cysts in rats a pparently mediated by increased sympathetic nerve activity and ovarian ster oid secretion. After 11 wk of stress, these parameters are indistinguishabl e from nonstressed control rats. To study adrenal contribution, we adrenale ctomized rats and studied the effect of 3-wk of cold/restraint stress (1.5 h/d) on them compared to intact animals. Adrenalectomy (ADX) increased ovar ian norepinephrine (NE) release, the content of beta-adrenergic receptors ( BAR) and basal, but not isoproterenol (Iso)-induced, androgen secretion. St ress to intact animals increased NE release, decreased beta AR content, and Iso-induced, but not basal, androgen secretion from the ovary. ADX did not modify the response to stress. We propose a tonic inhibition by the adrena l gland on nerve activity of ovarian nerves. Stress overrides this inhibito ry effect, and nerve activity downregulates beta AR, decreasing ovarian ste roid secretion.