Effect of Some Smooth Muscle Stimulants and Trypsin on the Contraction of Vas Deferens of Aging Rats

Abstract

Contractions of vas deferentia induced by KCl or field stimulation were not different between mature and old rats. The effect of trypsin or BaCl₂ but not bradykinin or carbachol on contraction induced by field stimulation was significantly different between mature and old rats. The increase of twitching contractions by trypsin may be due to its effect on presynaptic α-adrenoceptors. Trypsin treatment did not qualitatively alter the responses produced by agonists in the vas deferentia of mature and old rats.