Effect of intracerebroventricular injection of nicotinic acetylcholine receptor antibodies on ACTH, corticosterone and prolactin secretion in the male rat.

The aim of the present study was to investigate the involvement of CNS nicotinic receptors for acetylcholine in the secretory activity of the hypothalamo-hypophyseal-adrenal axis and prolactin (PRL). Adult male rats received a daily intraventricular injection of partially purified nicotinic acetylcholine receptor antibodies (anti-AChR) obtained from a female patient with myasthenia gravis, for 5 consecutive days. Control animals were treated similarly with immunoglobulins obtained from a healthy woman. Blood samples were withdrawn either under basal conditions or following ether stress. Treatment with anti-AChR increased basal ACTH and corticosterone (CS) levels (by approximately two-fold) but completely inhibited the responses of these hormones and PRL to ether stress. In control animals, normal basal and stress-induced responses of ACTH, CS and PRL were observed. This study demonstrated the importance for nicotinic acetylcholine receptors in the mediation of basal and stress-induced adrenocortical activity as well as for the mediation of PRL secretion in response to stress.