Uptake of and response to norepinephrine by certain tissues of hypertensive rats.

A decrease in the capacity of the sympathetic nervous system of hypertensive rats to take up norepinephrine (NE) has been previously described. In the present study, rats were made hypertensive by one of the following technics: "adrenal regeneration," figure-of-eight knot around one kidney, ingestion of a 10% NaCl solution. After 2 mo, the adrenal regeneration rats were hypertensive, and there was a significant decrease in the capacity of their hearts to take up NE as well as a significant increase in the inotropic response to the amine. Similar results were obtained with hearts and aortic strips of renal hypertensive rats, as well as of rats made hypertensive by drinking a 10% NaCl solution. In renal hypertensive rats, there was no appreciable difference in the time of appearance of hypertension, the decrease in NE uptake by the heart or aorta, or the increase of the inotropic response. Previous work showing a decrease of NE uptake in rats made hypertensive by administration of deoxycorticosterone has been confirmed utilizing three other models of the disease.