title: Studies on the stereoselectivity of the P2-purinoceptor on the guinea-pig vas deferens.
abstract: ATP, 2-chloro-ATP, 2-methylthio-ATP and their unnatural L-enantiomers, Rp and Sp diastereoisomers of the ATP phosphorothioate analogues, ATP alpha S and ATP beta S, were tested on the guinea-pig vas deferens. The 2-substituted analogues of ATP were no more effective than ATP in causing contraction of the vas deferens. However, stereoselectivity was observed with each pair of enantiomers of ATP, 2-chloro-ATP and 2-methylthio-ATP. No stereoselectivity was observed for the phosphorothioate analogues. Rp- and Sp-ATP beta S were more effective than ATP at eliciting contractions of the vas deferens. These results show that unlike the P2-purinoceptor mediating excitatory responses in the guinea-pig bladder, the P2-purinoceptor mediating contraction in the guinea-pig vas deferens displays stereoselectivity.
authors.forename: G
authors.initials: G
authors.lastname: Burnstock
authors.forename: N J
authors.initials: NJ
authors.lastname: Cusack
authors.forename: L A
authors.initials: LA
authors.lastname: Meldrum
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000378:metabolism*; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D011983:Receptors, Purinergic; D013237:Stereoisomerism; D014649:Vas Deferens / Q000378:metabolism
chemical_list: D017981:Receptors, Neurotransmitter; D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate