Changes in endocrine control of electrolyte homeostasis and blood pressure following heart and heart-lung transplantation. A comparative study.

The purpose of this study was to compare the early postoperative effects of heart and heart-lung transplantation on the secretion of atrial natriuretic peptide (alpha-ANP), renin, aldosterone, and vasopressin. This was carried out from the first to the eighth postoperative day in ten heart and five heart-lung recipients. The changes in the release of these hormones were similar in both groups. Vasopressin release remained stable while that of the renin-angiotensin-aldosterone system progressively returned to more normal levels. Grafted heart tissue was capable of high alpha-ANP release early on in both heart and in heart-lung recipients. This sustained alpha-ANP release was not a function of the resulting overall atrial tissue mass. Our findings suggest that it might be the consequence of an intrinsic hypersecretion of alpha-ANP resulting from the loss of normal heart innervation occurring in both heart and heart-lung transplantation.