Effect of chronic ethanol consumption on the pharmacological response of the rabbit corpus cavernosum.

Previous studies demonstrated that acute in vitro exposure of corpus cavernosal tissue to ethanol decreased its response to field stimulation and pharmacological stimulation. In the current study the effects of chronic ethanol consumption on the responses of the rabbit corpus cavernosum to field stimulation and various autonomic agonists were investigated. Five percent (V/V) ethanol in drinking water was given to rabbits for 6 weeks. At the end of this time the in vitro response of the corpus cavernosum to various forms of stimulation was determined. The corporal smooth muscle taken from rabbits subjected to chronic ethanol consumption demonstrated the following characteristics compared to tissue taken from control rabbits. (1) Under basal conditions, both relaxation and contraction induced by field stimulation were significantly increased. (2) Contractions to both phenylephrine and KCl increased significantly. (3) In the tissue preincubated with phenylephrine, relaxations induced by field stimulation, ATP, and bethanechol were significantly enhanced. (4) The relaxation responses to sodium nitroprusside were not changed by chronic exposure to ethanol. These findings suggest that in vivo chronic ethanol administration augmented both stimulated contracation and stimulated relaxation of the corporal smooth muscle.