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Atriopeptin III depresses the excitability of sympathetic neurones
1Department of Pharmacology, University of Toronto, Ontario, Canada.
Abstract:
The effect of atriopeptin III (AP III) on the excitability of the inferior mesenteric ganglion (IMG) of the guinea-pig was studied by intracellular recording technique. AP III depressed the excitability of the IMG by decreasing the frequency of the action potentials, prolonging the afterpotential and increasing the threshold of the action potentials. Voltage-clamp studies revealed that a transient potassium current-the A current-was enhanced by AP III. It is suggested that inhibition of the sympathetic nervous system may contribute to the cardiovascular effect of AP III.
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