Effects of atrial natriuretic peptide on glomerular filtration rate in essential hypertension: a radionuclide study.

A number of studies show that atrial natriuretic peptide (ANP) raises renal sodium excretion with a concomitant increase in glomerular filtration rate (GFR) in both experimental animals and normal humans. Studies using indirect evaluation of GFR have provided less consistent results in hypertensive patients. We studied the effects of intravenously administered (iv) alpha-human ANP on GFR in patients with hypertension by a radionuclide technique using technetium 99m diethylenetriaminepenta-acetic acid. In six patients (ANP group), GFR was determined under control conditions, during iv ANP (initial bolus of 0.5 micrograms/kg followed by a 21-min maintenance infusion at 0.05 micrograms.kg-1.min-1) and during a recovery phase. In six other patients (control group), GFR was determined under control conditions, during saline iv infusion and during recovery. The two groups did not differ with respect to age, sex, basal blood pressure, heart rate or GFR. In the ANP group, the infusion of the peptide induced a significant decrease of mean blood pressure (from 133 +/- 5 to 120 +/- 5 mmHg, P less than 0.01), no change in heart rate and a significant increase in GFR (from 104 +/- 4 to 125 +/- 5 ml/min, P less than 0.01). During recovery, blood pressure, heart rate and GFR were not different from the values recorded under control conditions. No changes in blood pressure, heart rate or GFR (from 106 +/- 5 to 108 +/- 5 ml/min, n.s.) were detected during saline infusion in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)