Uptake and Subcellular Distribution of Norepinephrine in the Canine Heart Following Experimental Myocardial Infarction 1

Abstract

Summary

Following surgical myocardial infarction in dogs, a marked decline in cardiac norepinephrine stores has been observed. In an attempt to elucidate the mechanism of the NE-depletion, the uptake, degradation, and subcellular distribution of norepinephrine in the canine myocardium were determined after myocardial infarction. The subcellular distribution, uptake and accumulation of tracer doses of dl-norepinephrine-7-¹⁴C were unchanged and the rate of degradation was not significantly increased. It appears thus, that the decline in cardiac norepinephrine stores following infarction is neither due to a decreased ability of the sympathetic nerve ending to take up and accumulate NE, nor to an increased rate of degradation.