Endothelin-1 circulating levels increase in patients with orthotopic heart transplantation and in chronic therapy with cyclosporine

Background. The aim of the study was to investigate the behaviour of plasma levels of endothelin-1 (ET-1), an endothelial peptide with vasoconstrictive and proliferative actions, in patients with cardiac transplantation and in chronic treatment with cyclosporine A, some of whom became hypertensive after cardiac transplantation. Methods. We studied: 1) 18 consecutive patients (15 M, 3 F; mean age 53±7 yrs) who underwent cardiac transplantation about six months ago at least (range 6-108 months); 2) 15 patients with essential arterial hypertension (10 M, 5 F; mean age 42±15 yrs) without organ damage; 3) 21 normal subjects (15 M, 6 F; mean age 31±12 yrs). Plasma levels of ET-1 (RIA), haemodynamic and functional renal parameters were determined in all groups and plasma levels of cyclosporine were measured in patients with cardiac transplantation. Results. ET-1 was higher in patients with cardiac transplantation than in the other two groups (p<0.05); instead there was no difference between patients with essential arterial hypertension and controls (p>0.05). A statistical difference was found between circulating ET-1 in hypertensive transplanted patients (61%) and those in normotensive transplanted patients. In heart transplanted patients a positive and significative correlation was found between plasma levels of ET-1 and systolic (r=0.792; p<0.0001) and diastolic (r=0.525; p<0.037) blood pressure. Conclusions. Our study shows that there is an increase of circulating ET-1 levels of in patients with heart transplanted patients and in particular in those who developed arterial hypertension. We can hypothesize that ET-1 plays an important role in the variation of systemic blood pressure.