Abstract
An elevated plasma atrial natriuretic peptide (ANP) concentration was observed in patients with chronic renal failure, and it was significantly (P<0.01) decreased by hemodialysis with or without fluid removal. The ANP concentration was decreased by dialysis without fluid removal and the decrease was significantly (P<0.01) correlated with the pre-dialysis value. The decrease in this peptide during fluid removal without diffusion was significantly (P<0.05) correlated with the decrease in the circulating plasma volume measured by dye dilution. The decrease in the ANP level was therefore considered to be related to a fall in right atrial pressure caused by the decline in the circulating plasma volume. The circulating plasma volume, osmotic pressure, and blood pressure were not changed by hemodialysis without fluid removal. Moreover, the filtrate concentration of ANP (mean: 5.5pg/ml) during fluid removal without dialysis was only about 8% of the plasma level, so filtration of ANP from the dialyzer was negligible. The decrease in ANP during hemodialysis without fluid removal may therefore have been caused by the removal of or a change in the level of substances, for example electrolytes, epinephrine, and uremic toxins. In addition to volume expansion, such a substance(s) might influence plasma ANP levels in patients with chronic renal failure.
