Elevation of plasma endothelin associated with systemic hypertension in humans following orthotopic liver transplantation

Endothelin (ET) is a 21-amino-acid peptide of endothelial origin, is a potent systemic and renal vasoconstrictor associated with sodium retention and modulation of the renin-angiotensin-aldosterone system. The present study was designed to determine if plasma ET is elevated in humans with cirrhosis (n = 12), a state characterized by sodium retention and increased plasma renin activity (PRA) and plasma aldosterone (PA), and to determine the effect of orthotopic liver transplantation (OLT) upon plasma ET, PRA, and PA at 1, 3, and 7 days after transplantation. Plasma ET before OLT was 1.62±0.23 pg/ml, which was not different as compared with normal controls. Plasma ET significantly increased to 4.18±0.66, 3.87±0.58, and 4.07±0.61 pg/ml, respectively following OLT. PRA remained elevated throughout the postoperative course, in contrast to PA that decreased following OLT. Mean arterial pressure increased significantly from 82±4 pre-OLT to 98±4 and 103±2 mmHG on days 3 and 7 respectively. In conclusion, the current studies document that circulating ET is normal in cirrhotics but is significantly increased following OLT, and was associated with an early hypertensive response. These studies suggest a possible role for ET, the cardiorenal response to OLT.