Determination of Infused Epinephrine and Norepinephrine in Plasma Using Isolated Guinea Pig Heart Technique
Experiments have been described which show the very high sensitivity of the isolated perfused guinea pig heart preparation in the estimation of plasma levels of catecholamines after intravenous infusion in dogs. It was observed that crude plasma samples show the same pattern of positive inotropic response as extracts of these samples. By means of the isolated guinea pig heart method, the presence of circulating catecholamines could still be detected 30 minutes after the end of infusion.
The observation that dichloroisoproterenol may block the positive inotropic effect of epinephrine, while only slightly reducing the positive inotropic effect of norepinephrine, may be used to differentiate between these two catecholamines.
- Received May 16, 1962.
- © 1962 American Heart Association, Inc.