Plasma circulating endothelin-1 in on-pump coronary surgery cardiopulmonary bypass

摘要

Endotheline-1 (ET-1) is an endothelium-derived potent vasoconstrictor peptide of 21 amino acid residues. On-pump coronary surgery is realized with cardiopulmonary bypass (CPB) and initiates physiologic changes, which can induce ET-1 synthesis. The purpose of this study is to determine and compare the plasma ET-1values before and after CPB. Ten patients comprised 2 female and 8 male undergoing coronary artery bypass grafting are investigated, having CPB. EDTA-plasma samples are collected 10 minutes before the extracorporeal circulation (CPB), 1 hour and 2 hours postoperatively. ET-1 is extracted by acetone from 1 ml of plasma and subjected to a sensitive enzyme-linked immunosorbent assay. Plasma levels of ET-1 in the 10 subject before the CPB are 0.68 ± 0.11 fmol/ml (mean ± SD, n=10), ranging from 0.57 to 1 fmol/ml. At 1 hour CPB plasma ET-1 levels are 17 % and 39 % less in 1 male and 1 female patient respectively, as compared to Et-1 values before the operation. The same male and female patients showed 11 % and 33 % less ET-1 concentration respectively, after 24 hours from the operation. ET-1 concentration is significantly increased in only 1 male patient, by 20 % as compared to the base value. Pre- and postoperative plasma ET-1 concentrations are in the range of normal human subjects. The postoperative decrease of the ET-1 concentration in patients may be to its binding to ET receptors and thus reduce its circulating values. The increase of ET-1 level in one patient may be associated with endothelium injury.