The role of the adrenergic nervous system in the renal response to acute extracellular fluid volume expansion.

Abstract

SummaryThe role of the adrenergic nervous system in the renal response to acute extracellular fluid (ECF) volume expansion was examined in the same dogs before and after catecholamine depletion with reserpine. In the control experiments before reserpine, acute ECF volume expansion produced marked increases in glomerular filtration rate (GFR). pamino-hippurate clearance (CPAH), mean arterial pressure (MAP), urine flow (V), sodium excretion (UNaV) and osmolar clearance (Cosm). One week later the same animals were studied under the same experimental conditions except for generalized impairment of the adrenergic nervous system secondary to catecholamine depletion with reserpine. The ECF volume expansion produced very similar increases in GFR, CPAH and filtered loads of sodium (FNa) before and after reserpine; however, the MAP, and thus renal perfusion pressures, were significantly lower after reserpine. Diminished urine flows (V), sodium excretion rates (UNaV) and osmolar clearances (Cosm) occurred after rese...