The role of the adrenoceptors in the activation of the hypothalamic-pituitary-testicular complex of mice induced by the presence of a female.

A study was made of the role of the adrenergic processes in the activation of the testes endocrine function in male mice of CBA/Lac and A/He strains after their sexual arousal induced by the presence of a sexually receptive female without any tactile contact with a male. The alpha-adrenoceptor blocker phentolamine and the alpha 1-adrenoceptor antagonist prazosin inhibited an increase of testosterone level in the peripheral blood plasma caused by the presence of a female. In contrast, antagonist of the beta-adrenoceptor propranolol and beta 2-adrenoceptor blocker ICI-118.551 significantly intensified the stimulating effect of the female presence on plasma testosterone level. The expression of effects of the adrenoceptor antagonists on the plasma testosterone level depended on a male genotype. At the same time, pretreatment of males with yohimbine, an antagonist of the alpha 2-adrenoceptors, or with metoprolol, a beta 1-adrenoceptor blocker, did not influence the activating effect of a female on the plasma level of testosterone. A conclusion was drawn that during sexual arousal in male mice caused by the presence of a receptive female, the stimulatory effects on the hypothalamic-pituitary-testicular complex were produced through the alpha 1-adrenoceptors, and the inhibitory effects were realized through the beta 2-adrenoceptors.