Effect of methoxamine on spontaneous motility of the isolated rat uterus.

In the present study the effect of methoxamine and its modification by several adrenergic antagonists is described in the isolated oestrogenized rat uterus. Methoxamine produced a dose-related increase in uterine activity, prazosin produced a rightward displacement of the dose-response curve of methoxamine reaching the same maximal effect. Yohimbine abolished the contractile response to methoxamine. propranolol or reserpine failed to modify the effect of methoxamine. Pretreatment with reserpine abolished the inhibitory effect of yohimbine. These results suggest the presence of excitatory alpha-adrenoceptors in the rat uterus.