Possible involvement of Ca(2+)-related inward current in P2-purinoceptor-mediated depolarization of the guinea-pig vas deferens.
The effect of a Ca2+ antagonist or Ca2+ chelator on the membrane responses elicited by P2-purinoceptor activation was examined in current- and voltage-clamped muscle from the guinea-pig vas deferens. The non-hydrolyzable ATP-analogue 5'-adenylylimidophosphate (AMP-PNP) depolarized the membrane and the associated inward current. Superfusion with Ca(2+)-free solution containing Co2+ or EGTA markedly suppressed the AMP-PNP-induced membrane response, thereby suggesting that the inward current responsible for the depolarizing effect of AMP-PNP may involve activation of a Ca(2+)-related conductance.
Inomata
H
H
Department of Applied Physiology, Tohoku University School of Medicine, Sendai, Japan.
Ji
J J
JJ
Utagawa
A
A
D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology; D015220:Calcium Channels / Q000502:physiology*; D003035:Cobalt / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D006868:Hydrolysis; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D011983:Receptors, Purinergic / Q000187:drug effects / Q000502:physiology*; D014649:Vas Deferens / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
D015220:Calcium Channels; D011983:Receptors, Purinergic; D000266:Adenylyl Imidodiphosphate; D003035:Cobalt; D004533:Egtazic Acid; D002118:Calcium