Renin response to sympathetic stimulation in cyclosporin-treated heart-transplant patients

Cyclosporin is an effective drug in treating rejection after cardiac transplantation. However, it causes serious side effects such as hypertension and decreased renal function.1,2 The exact nature of these renal effects has not been fully established. Previous studies have shown that the plasma renin activity (PRA) levels during long-term treatment with cyclosporin are either normal or low.1–4 The present study was performed to investigate the renin response to sympathetic stimulation produced by infusion of isoprenaline and during change in posture in cardiac transplant patients undergoing long-term treatment with cyclosporin.