Plasma norepinephrine kinetics are unaltered in chronically undernourished adult subjects

Twelve healthy adults divided into a well-nourished (WN; n = 6) and a chronically energy deficient (CED; n = 6) groups underwent a single 30 min infusion of norepinephrine (NE) administered at the rate of 0.15 micrograms/kg fat-free mass/min. Measured parameters in the basal state and during the infusion included heart rate (by electrocardiograph), stroke volume, cardiac output and other cardiac indices (by impedance cardiography) and blood pressure recordings. The data are suggestive of fairly similar cardiovascular responses in the CED and WN subjects, with the exception of cardiac inotropy (i.e. strength of cardiac muscle contractility) and changes in total peripheral resistance, both of which were enhanced in the CED. Peak NE levels of both groups during the infusion were similar and so was the clearance rate for NE corrected for fat-free mass differences. Although plasma half-life of NE tended to be higher in the CED group, plasma appearance rates of NE were comparable between the groups, suggesting that plasma NE kinetics were not altered in CED adults.