[Effect of depolarizing factors on the contractile activity of the smooth muscle of stomach vessels].
In isolated strips of the pig left gastral artery, potassium and electrical stimulation were shown to elicit gradual contractile responses of the contracture type. This effect was abolished by the blockage of calcium permeability of the membranes with manganese ions. Fast stretching evoked no contractile response, while the slow one potentiated the contraction. Activation of the smooth muscle contractile apparatus seems to be due to calcium extracellular ions coming into the cell during depolarization of membrane. Further functioning of the contractile mechanism and the final physiological effect depend on interaction of the membraneous and intracellular links of electromechanical conjugation controlling the intracellular concentration of the calcium ions.
D000818:Animals; D001158:Arteries; D004558:Electric Stimulation; D008345:Manganese / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology*; D010812:Physical Stimulation; D011189:Potassium Chloride / Q000494:pharmacology; D013270:Stomach / Q000098:blood supply*; D013552:Swine
D008345:Manganese; D011189:Potassium Chloride
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