Androgens and effects of opioids and catecholamines on the smooth muscle of the rat vas deferens¹

In the neuronal electrically stimulated vas deferens of the rat, the responses evoked by morphine, β-endorphin and catecholamines were studied. The tissue was obtained from rats at various times (7-60 days) following castration, adrenalectomy and castration with adrenalectomy. Pharmacological data are presented which verify an increased reponsiveness to morphine after castration with or without adrenalectomy. In contrast, decreased responsiveness was observed after adrenalectomy alone. Decreased responsiveness of the vas deferens to catecholamines was observed after castration, adrenalectomy and castration with adrenalectomy. Since the responsiveness of the electrically stimulated vas deferens to β-endorphin was unchanged by this treatment (castration, adrenalectomy), it is suggested that the 'ε-opioid' receptor is unaffected by androgens.