The Role of the Adrenoceptors in the Activation of the Hypothalamic-Pituitary-Testicular Complex of Mice Induced by the Presence of a Female

Summary

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 α-adrenoceptor blocker phentolamine and the α₁-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 β-adrenoeeptor propranolol and β₂-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 antogonist of the α₂-adrenoceptors, or with metoprolol, a β₁-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 α₁-adrenoceptors, and the inhibitory effects were realized through the β₂-adrenoceptors.

Key words

Sexual arousal - Adrenoceptors' subtypes - Testosterone regulation