Water immersion induced alterations of plasma atrial natriuretic peptide (ANP), diuresis and natriuresis in kidney transplant patients

Abstract

The present article aimed to study the intactness of the physiological mechanism of ANP secretion in 64 kidney transplant patients treated with cyclosporine A + prednisone (CyA group--35 patients) or azathioprine + prednisone + promethasine respectively (Aza group or--29 patients). The control group comprised 15 healthy persons. ANP plasma levels were assessed before and 1 h and 2 h after neck out water immersion (WI). Higher basal ANP levels were found in patients of the CyA and Aza group than in normals (significantly higher in patients of the CyA group). WI induced an increase of plasma volume (PV) which was of comparable magnitude in all examined groups. It was accompanied by a significant increase of plasma ANP, diuresis and of natriuresis, which was significantly lower in transplanted patients than in normals. Only in healthy persons a significant positive correlation was found between the WI induced increase of plasma ANP and diuresis and natriuresis respectively.

Conclusions: 1) kidney transplant patients are characterized by an intact, although reduced response of ANP secretion, diuresis and natriuresis to central hypervolaemia; 2) WI induced increase of diuresis and natriuresis does not seem to be only dependent upon ANP secretion in kidney transplant patients; 3) kind of immunosuppressive therapy seems to be of importance in the pathogenesis of altered ANP secretion in kidney transplant patients.