title: Pharmacological effects of L-AMP-PCP on ATP receptors in smooth muscle.
abstract: The pharmacological effects of ATP and of two of its analogues, AMP-PCP and L-AMP-PCP, were investigated in various isolated smooth muscle preparations. In the guinea-pig vas deferens, the rat portal vein and the rat anococcygeus the nucleotides all caused contraction, and the order of potency was L-AMP-PCP greater than AMP-PCP greater than ATP. In the guinea-pig field-stimulated ileal longitudinal muscle the nucleotides all inhibited the contractions, and the order of potency was ATP greater than AMP-PCP greater than L-AMP-PCP. In the guinea-pig thoracic aorta ATP and AMP-PCP caused relaxations, ATP being more potent than AMP-PCP, and L-AMP-PCP caused contractions. These results are consistent with the suggestion that the ATP receptors mediating contraction of smooth muscle are different from those mediating relaxation, and show that L-AMP-PCP is a potent, specific agonist at excitatory ATP receptors.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011983:Receptors, Purinergic / Q000187:drug effects / Q000378:metabolism*
chemical_list: D011983:Receptors, Purinergic; C005147:5'-adenylyl (beta,gamma-methylene)diphosphonate; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D009638:Norepinephrine