[Direct effect of reserpine. II. Response of the rat vas deferens to calcium].

It has been shown that reserpine competitively antagonises the response of the isolated rat vas deferens to Ca2+. It has also been shown that reserpine does not modify uptake of Ca2+ from the external medium. On the basis of the results obtained and bearing in mind the uncoupling effect of reserpine on oxidative phosphorylation, it is suggested that reserpine owes its "direct" action to reduced availability of Ca2+ for contraction due to metabolic block.