Summary: | Antagonistic inotropic actions of barbiturates and adrenergic amines have, been demonstrated in dog hearts. The present work was undertaken to ascertain whether a similar antagonism occurred in other tissues, and if so, how specific and potent it is.
The tissues selected for studying these phenomena were rabbit kidney cortex slices, uterine horns of previously estrogenized rabbits and guinea pig terminal ileum. The tone and contractility of the isolated smooth muscle preparation and the active transport of sodium para-aminohippuric acid (PAH) by the kidney cortex slices, were the processes monitored.
No antagonism of the barbiturate induced depression of the active uptake of PAH by kidney cortex slices on the part of adrenergic amines was observed. Only a weak antagonism between these two groups of drugs was evident under suitable conditions in the guinea pig ileum. However, in contrast to these observations, a potent antagonism similar to that demonstrated in the dog hearts, was evident in the rabbit uterine horns.
The experimental data indicated that adrenergic amines and barbiturates are antagonistic only in those tissues where barbiturates depress and adrenergic amines stimulate the energy utilizing process studied. The antagonism when evident is not specific and may be classified as independent or physiological. === Medicine, Faculty of === Anesthesiology, Pharmacology and Therapeutics, Department of === Graduate
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