Effect of Adrenergic Antagonists on the Peripheral Constrictor Action of Kinekard, A Cardioactive Plasma Fraction
The possibility that endogenous epinephrine, norepinephrine or angioten-sin is involved in the response of the peripheral circulation to kinekard, a plasma pressor fraction of relatively low molecular weight, was investigated in anesthetized dogs on heart-lung bypass and isolated perfused gracilis muscle preparations. The prior administration of bretylium tosylate, guanethidine or the β-adrenergic antagonist, propranolol, failed to modify the pressor action of kinekard. This pressor action was blocked by the prior addition of the α-adrenergic antagonist, phenoxybenzamine. These results have been interpreted to mean that kinekard acts on the α-receptor sites in the peripheral circulation to cause constriction and that this response does not involve or depend on the release of stored catecholamines.
- peripheral circulation
- propranolol plasma pressor activity
- adrenergic blockade
- kinekard and α-receptors adrenergic mechanisms
- anesthetized dogs
- Accepted April 11, 1966.
- © 1966 American Heart Association, Inc.