Breakdown of extracellular ATP by the prostatic and epididymal ends of the guinea pig vas deferens.

Adenosine 5'-triphosphate (ATP) has a higher potency at the prostatic than at the epididymal end of the guinea pig vas deferens. We bisected the tissue and measured the breakdown of ATP by each half, and although the half-lives differed, the rate constants per gram of tissue were not significantly different. For a range of tissue portions, a correlation was found between the portion weight and the half-life of ATP. The difference in half-life at the two ends is therefore due to the different weights of the tissues, and the difference in potency of ATP cannot be explained by differences in degradation.