The effects of olmesartan on asymmetric dimethyl arginine and inducible nitric oxide synthase levels in coronary artery bypass grafting patients done with cardiopulmonary bypass technique

ABSTRACTTHE EFFECTS OF OLMESARTAN ON ASYMMETRIC DIMETHYL ARGININE AND INDUCIBLE NITRIC OXIDE SYNTHASE LEVELS IN CORONARY ARTERY BYPASS GRAFTING PATIENTS DONE WITH CARDIOPULMONARY BYPASS TECHNIQUESystemic inflammatory response syndrome (SIRS) is commonly seen in patients who undergo coronary artery bypass graft (CABG) surgery by cardiopulmonary bypass (CPB) technique. Olmesartan, an angiotensin II receptor blocker is known to reduce oxidative stress and inflammatory effects. In this study, effect of olmesartan therapy on asymmetric dimethyl arginine (ADMA) and inducible nitric oxide synthase (iNOS) levels was investigated in patients who undergo cardiopulmonary bypass graft surgery.A total of 50 patients aged between 30-80 years and who will undergo CABG were included in the study. Patients were randomly allocated to two groups (Group C: Control, Group O: Olmesartan). Patients in Group C received no treatment. Patients in Group O were administered 30 mg olmesartan once a day beginning from preoperative 5. day to postoperative 28. day and on operation day. Blood was drawn from all patients and ADMA and iNOS levels were analysed for six times (T1: before anesthesia induction, T2: during cardiopulmonary bypass, T3: five min after the cross-clamp was removed, T4: after protamine infusion, T5: postoperative 3. day and T6: postoperative 28. day).iNOS expression level was seen to be significantly lower at T2, T5 and T6 times in olmesartan group compared to control group. In-group comparison of control group, iNOS expression levels were seen to be significantly high in times involving cardiac surgery. In olmesartan group, iNOS expression levels were high in times of CPB and after cross clamp had been removed and these elevations were not as high as control group.In this study, ADMA was seen to be lower in olmesartan group compared to control group. In control group, serum ADMA levels were seen to be significantly elevated in T2, T5 and T6 times compared to T1. In olmesartan group, serum ADMA levels were significantly higher in T2, T3 and T4 times compared to the time before anesthesia induction.It was concluded that olmesartan administration reduced serum ADMA and iNOS levels in CPB time and it could reduce potential postoperative complications through reducing oxidative stress and inflammatory response in postoperative period in coronary bypass surgery.Key words: systemic inflammatory response syndrome, asymmetric dimethyl arginine, inducible nitric oxide synthase