ATRIAL-NATRIURETIC-PEPTIDE RELEASE AND VOLUME REGULATION FOLLOWING KIDNEY-TRANSPLANTATION

The major stimulus for atrial natriuretic peptide (ANP) release is atr ial stretch and increased values are observed in volume overload state s such as chronic renal failure. Since successful kidney transplantati on restores volume homeostasis, we compared the effects of human cadav eric kidney transplantation on time course and changes of plasma ANP i n the early postoperative period in 4 patients with successful and 4 p atients with failed transplantation. ANP concentrations were elevated before transplantation in both groups (91 +/- 16 and 70 +/- 32 pmol/1) and decreased after successful (50 +/- 27 pmol/l, day 16) but increas ed after failed transplantation (146 +/- 45 pmol/l, day 16). Moreover, there was a close correlation between changes of body weight and ANP concentrations. Plasma renin activity decreased and plasma noradrenali ne increased non-significantly in both groups, the latter more so afte r failed transplantation (116 +/- 42 to 194 +/- 156 vs 156 +/- 157 to 425 -/+ 287 ng/1). No correlation was found between changes of renin a ctivity or plasma catecholamines and ANP concentrations. The results i ndicate that the mechanisms governing release of atrial natriuretic pe ptide are operative in patients with chronic end-stage renal failure a nd after successful kidney transplantation with a return of atrial nat riuretic peptide concentrations towards normal in the latter.