[Role of the natriuretic factor in the phenomenon of "exaggerated natriuresis" in experimental hypertension].

Water and electrolyte excretion after a salt load, plasma natriuretic activity, and sensitivity of the kidneys to the natriuretic factor were studied in experiments on Wistar rats with renal hypertension and on SHR rats with spontaneous hypertension. The "exaggerated natriuresis" phenomenon is observed in animals with hypertension after a salt load. The plasma natriuretic activity in rats with experimental hypertension does not rise in response to an increse in the volume of extracellular fluid. The sensitivity of the kidneys to the natriuretic factor in animals with experimental hypertension is the same as that in the control animals. Consequently, the natriuretic factor has no decisive role in the "exaggerated natriuresis" phenomenon in these types of experimental hypertension.