Some pharmacological and biochemical interactions of the enantiomers of adenylyl 5'-(beta, gamma-methylene)-diphosphonate with the guinea-pig urinary bladder.

Adenosine 5'-triphosphate (ATP) and adenylyl 5'-(beta, gamma-methylene)-diphosphonate (AMP-PCP) both contracted the guinea-pig urinary bladder, but the response to AMP-PCP was much greater. We synthesized the enantiomer of AMP-PCP, L-adenylyl 5'-(beta, gamma-methylene)-diphosphonate (L-AMP-PCP), and tested it on the guinea-pig bladder. L-AMP-PCP contracted the guinea-pig bladder, and was more potent than AMP-PCP and much more potent than ATP. The potential breakdown product of L-AMP-PCP, L-adenosine, unlike adenosine (the breakdown product of AMP-PCP), did not inhibit contractions of the guinea-pig bladder. ATP and its enantiomer L-adenosine 5'-triphosphate (L-ATP) were rapidly degraded by the muscle, and AMP-PCP was also degraded, but more slowly. L-AMP-PCP, however, was completely resistant to degradation. L-AMP-PCP would appear to be a useful ATP analogue, as it is potent and resistant to degradation, and its potential breakdown product, L-adenosine, is inactive.