Influence of hemodialysis on the plasma levels of the atrial natriuretic factor in chronic renal failure.

Atrial natriuretic factor, plasma renin activity, and plasma vasopressin were measured in 38 patients with chronic renal failure prior to and after hemodialysis. The objective of the study was to evaluate the effect of acute volume changes on the level of atrial natriuretic factor. Blood pressure prior to dialysis was 154 +/-/83 +/- mmHg, and 132 +/-/78 +/- mmHg post dialysis (p less than 0.005) while heart rate increased from 82.5 +/- 1.8 beats per minute to 91.2 +/- 2.4 after dialysis (p less than 0.005). The average weight of patients was reduced from 60.2 +/- 2.4 kg to 57.8 +/- 2.4 kg (p less than 0.005). While the plasma levels of atrial natriuretic factor in normal individuals were 65.3 +/- 2.9 pg/ml (n = 59), these levels were 251.4 +/- 28 pg/ml prior to dialysis in the patients with renal failure, and 173.3 +/- 18.0 pg/ml after dialysis (p less than 0.005). Twenty-nine patients had a reduction in the levels of this atrial natriuretic factor, 5 had no change, and 4 had an increase. The atrial factor was not detected in the dialysate fluid of 6 patients in whom it was measured. Peripheral renin values were unchanged from 2.12 +/- 0.68 to 2.07 +/- 0.8 ng/ml/hr. Plasma vasopressin before dialysis was significantly higher than normal, and increased from 7.04 +/- 0.56 to 9.95 +/- 1.55 pg/ml following dialysis (p less than 0.05). The changes in atrial natriuretic factor values correlated most significantly (r = 0.47, p less than 0.005) with the changes in weight, but no single variable could explain the changes in atrial natriuretic factor.