Effects of alpha, beta-methylene ATP on electrical responses produced by ATP and nerve stimulation in smooth muscle cells of the guinea-pig mesenteric artery.
1. In smooth muscle cells of the guinea-pig mesenteric artery, alpha, beta-methylene ATP(mATP) depolarized the membrane and decreased the membrane resistance. 2. Desensitization with mATP inhibited the excitatory junction potential (e.j.p.) and ATP-induced depolarization, while desensitization with ATP inhibited the e.j.p. but not the mATP-induced depolarization. 3. After desensitization with mATP, the response to mATP recovered rapidly in comparison with the e.j.p. and the ATP-induced depolarization. 4. The results suggest that mATP inhibits the ATP-induced depolarization by acting sites other than the ATP-receptor.
Nagao
T
T
Department of Pharmacology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Suzuki
H
H
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D013997:Time Factors
D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D009638:Norepinephrine