CIRCULATING ENDOTHELIN IN CARDIAC OPERATIONS - INFLUENCE OF BLOOD-PRESSURE AND ENDOTOXIN

Background. Endothelin is involved in the control of cardiovascular an d renal functions and acts as a neuromodulator. Methods. In a prospect ive study among 15 male patients who underwent coronary artery bypass grafting, we investigated the release pattern and possible stimuli of circulating endothelin. Results. We detected a steep increase in endot helin concentrations after the onset of cardiopulmonary bypass (CPB), and a second minor increase during CFB. The steep increase in endothel in concentrations correlated with the change in arterial pressures at the onset of CPB (r = -0.57; p < 0.03). The slow increase in endotheli n concentrations during CPB, however, correlated with mean endotoxin l evels during and after CPB (r = 0.60; p < 0.02). Conclusions. The chan ge in arterial pressure at the onset of CPB seems to induce a steep an d fast increase in circulating endothelin level, which is probably med iated through the baroreceptors. The slow increase in endothelin level during CPB is associated with increased circulating endotoxin concent ration. It may be that either endothelin-mediated vasoconstriction ind uces endotoxin transmigration from the intestine or endotoxin stimulat es endothelin secretion from endothelial cells.