Actions of nicotine on renal function in dogs.

Abstract

Renal excretory and circulatory responses to nicotine were investigated in anesthetized dogs under three sets of conditions: (a) infusion of nicotine into the left renal artery (ia) at a dose of 0.5 microgram X min-1 X kg body wt-1 X 15 min; (b) ia nicotine after 1.0 mg/kg ia propranolol; and (c) ia nicotine after bilateral adrenalectomy. Measured and calculated left and right renal excretory variables included sodium, potassium, and chloride excretion rates (UNaV, UKV, and UClV, respectively), total solute excretion (UOsV), glomerular filtration rate (GFR), fractional sodium excretion (FENa), and urine flow rate. Systemic arterial pressure and left renal artery blood flow (RBF) were also measured. In seven intact dogs administered nicotine alone, there were significant increases in UNaV, UClV, UOsV, GFR, and urine flow rates from both kidneys. However, nicotine did not significantly affect UKV, FENa, arterial pressure, or RBF. The lack of circulatory effects of nicotine was also observed after either propranolol or adrenalectomy. However, when nicotine was administered after propranolol, the drug evoked significant decreases in UOsV, UNaV, UClV, and GFR, compared with prenicotine values. When nicotine was administered after bilateral adrenalectomy, the drug evoked decreases in the excretory parameters similar to those observed after propranolol. These findings seem to support several inferences: (a) nicotine stimulates renal excretory functions-the alkaloid is saluretic and diuretic; (b) the action of nicotine on the kidney is mediated mainly by the release of catecholamines from the adrenal medulla; (c) catecholamines released by nicotine act mainly on beta-adrenergic receptors; and (d) the saluresis prompted by the release of catecholamines in response to nicotine is due to a subsequent increase in GFR.