[Norepinephrine-induced pressor diuresis blockade as a possible cause of hypertension]

The effect of norepinephrine infusion at a constant rate (0.8 or 2.5 microg/kg/min), i.v.) on the diuiresis, sodium excretion with urine, glomerular filtration, and arterial pressure (AP) was studied in acute experiments on dogs. The sodium excretion was calculated as percentage relative to the filtration charge. Norepinephrine infusion at a constant rate of 0.8 microg/kg/min led to an increase in the urine volume, in the amount of excreted sodium with increased AP (pressor diuresis effect), and glomerular filtration with increasing AP, while the level of reabsorption remained unchanged. An increase in the infusion rate to 2.5 microg/kg/min, led to a decrease in the urine volume, the level of sodium excretion, and the rate of glomerular filtration. In this case, the AP level was higher than that in the first series of experiments, and the level of sodium reabsorption was increased.