Effects of cardiopulmonary bypass on expression of apelin and salusin and ınvestigation of whether or not they are locally synthesized in the aorta, saphenous vein and artery graft

The present study aimed to examine the effects of cardiopulmonary bypass (CPB) on salusin-?, salusin-ß and apelin-36 bioactive peptides in people who are planned to undergo coronary artery bypass graft operation (CABG) due to coronary artery disease and to explore whether these peptides are produced in human aortic, saphenous and arterial tissues. The study included age- and BMI-matched 15 patients who underwent CABG operation by CPB. In order to determine salusin-?, salusin-ß and apelin-36 levels, venous blood samples were collected before induction of anaesthesia (T1), before CPB (T2), 5 minutes before the removal of cross-clamp (T3), 5 minutes after the removal of cross-clamp (T4), upon arrival in the intensive care (T5), at postoperative 24th hour (T6) and 72nd hour (T7). Before CPB, 1 cm samples were taken from the vascular structures prepared as autogenous grafts to establish salusin and apelin-36 expressions. Salusin and apelin expressions of the tissues were shown by immunohistochemical method. Peptide amounts of sera and tissues were measured using Enzyme-Linked Immunosorbent Assay (ELISA). Salusin production by vessels occurs in fibroblast cells of the media in the aorta and smooth muscle cells of the media in the LIMA and saphena. Apelin is produced by endothelial cells of the intima and fibroblast cells of the media in the aorta and by smooth muscle cells of the media in the LIMA and saphena. Changes in the levels of salusin-? were not statistically significant. Salusin-ß amounts of T1 and T2 blood samples were found similar, while they dropped in T3 blood samples, were the lowest in T4 blood samples and gradually increased in T5 to T7 blood samples. Changes in apelin-36 levels were similar to those in salusin-ß. In conclusion, it was observed that salusin-?, salusin-ß and apelin?36 were synthesized in the arteries and veins, that salusin-ß and apelin?36 might be important markers in the CPB, and that salusin-ß peptide was more specific in comparison to salusin-?.