The role of transmembrane sodium gradient in rabbit ileal smooth muscle: utilization of harmaline.
Decreasing extracellular sodium concentration was found to produce a contractile response of rabbit ileal smooth muscle. As the concentration decreases, the amplitude of contraction increases, thus producing a dose-dependent curve. Harmaline, a competitor for sodium, was found to inhibit the sodium gradient-dependent contractions in a dose-dependent manner. The results are interpreted as harmaline inhibiting a Na-Ca exchange mechanism present in ileal smooth muscle.
D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D006246:Harmaline / Q000494:pharmacology*; D007082:Ileum / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000502:physiology*; D011817:Rabbits; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology*
D000470:Alkaloids; D012964:Sodium; D006246:Harmaline