Effect of in vivo and in vitro ethanol on adrenergic and purinergic responses of the bisected rat vas deferens to low and high frequency pulses.

1. This study investigates the effect of acute in vivo and in vitro ethanol administration on the contractions evoked electrically and by exogenous noradrenaline and alpha,beta-methylene-ATP in the rat bisected vas deferens. 2. In vivo ethanol treatment (3 g kg(-1), i.p.) significantly potentiated the early purinergic (phase I) and the delayed adrenergic (phase II) phases evoked by single-pulse stimulation of the epididymal portion of the rat vas deferens, leaving unaffected both phases in the prostatic portion. In vitro 50 mM ethanol significantly depressed phase I leaving unaffected phase II in both portions from untreated rats. In vitro ethanol significantly depressed phase I in the epididymal portion from in vivo ethanol treated animals and potentiated phase II in both portions. 3. In vivo ethanol treatment (3.0 g kg(-1), i.p.) selectively impaired the response to noradrenaline only in the prostatic portion of rat vas deferens while it was devoid of any action on alpha,beta-methylene-ATP contractions. Ethanol 50 mM in vitro was devoid of any action on the response to exogenous noradrenaline and alpha,beta-methylene-ATP in both tissues. 4. In vivo ethanol treatment slightly but significantly increased the phasic response in the epididymal portion to trains of stimuli (2-30 Hz). In vitro 50 mM ethanol was ineffective against the phasic and tonic contractions elicited by the tetanus in both portions. 5. It is concluded that ethanol treatment affects purinergic and adrenergic pathways of transmission possibly leading to a disruption of physiological contractions necessary to seminal emission.