Effects of phosphorothioate analogues of ATP, ADP and AMP on guinea‐pig taenia coli and urinary bladder

Abstract

1 Phosphorothioate analogues of ATP, ADP and AMP were tested on the guinea-pig taenia coli and urinary bladder. 2 The Rp diastereoisomers of the phosphorothioate analogues, ATP-α-S and ADP-α-S were respectively 7 and 3 times more effective than the Sp diastereoisomers in causing relaxation of the taenia coli. No stereoselectivity was observed for the diastereoisomers of ATP-β-S. 3 In guinea-pig bladder, no stereoselectivity was observed for any of the phosphorothioate analogues. 4 These results show that P₂-purinoceptors mediating inhibitory responses in the guinea-pig taenia coli show marked stereoselectivity, while P₂-purinoceptors mediating excitatory responses in the guinea-pig bladder show little stereoselectivity.