Received: 2014-08-06
Revised: 2014-08-20
Accepted: 2014-10-11
Lipid Peroxidation Product and Glutathione Levels in Patients with Coronary Heart Disease Before and After Surgery
Rahman Khansha1, Behnoosh Miladpour2, Zohreh Mostafavi-Pour2, Fatemeh Zal3
1 Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
2 Biochemistry Department, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
3 Reproductive Biology Department, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran.
|
Abstract
Background: It has been reported that ischemia-reperfusion is associated with augmentation of oxidative stress and its specific and sensitive markers. Oxidative stress may cause atrial fibrillation (AF) which is a common consequence after cardiac surgery. Dietary supplementation with antioxidants might lower the incidence of AF following coronary artery bypass graft (CABG) surgery.Materials and Methods: Fifty patients with coronary heart disease (CHD) referred to Namazi and Faghihi Hospitals in Shiraz, undergone elective CABG, were enrolled in this study. For evaluation of oxidative stress, whole blood was taken before and 24 hours after surgery and malondialdehyde (MDA) as an oxidative marker and glutathione (GSH) as an antioxidant marker were measured.Results: Results showed a significant difference between the mean concentration of GSH before and after CABG surgery (P <0.05); however, the difference in plasma MDA levels before and after CABG was insignificant.Conclusion: CABG surgery results in oxidative stress and reduces GSH 24h after surgery and administration of antioxidants may attenuate post-operative oxidative stress.[GMJ.2015;4(2):78-82]
Keywords: Coronary Artery Bypass Grafting; Oxidative Stress; Malondialdehyde; Glutathione; Lipid Peroxidation
|
Introduction
Oxidative stress has a critical role in pathophysiology of atherosclerosis and acute thrombotic events including dyslipidemia leading to oxidation of low density lipoprotein (LDL), atheroma formation, plaque rupture and recurrent thrombosis. Moreno and Fuster showed the relationship between various coronary diseases risk factors like elevated blood pressure, diabetes and cigarette smoking with atrial diseases [1]. Atrial fibrillation (AF) is a common complication of cardiac surgery because of electrophysiological and structural changes of coronary heart arteries [2]. Incidence of AF after coronary artery bypass grafting (CABG) surgery is dependent on age, severity of cardiac disease, case complexity and co-morbidities. AF can increase complications such as strokes, co-medication consumption, duration of admission and mortality in hospital and also can reduce survival after surgery [3]. Main factors leading to AF are cardiac overload initiating atrial electrophysiological remodeling and inflammation, starting a second messenger system and cause oxidative stress [4, 5]. After transient ischemia, the tissue releases reactive oxygen species (ROS) which are specific and sensitive markers for inflammation and oxidative stress. ROS release in reperfused myocardium may be used as a method for comparing inflammatory process in CABG. [6,7].
In addition to beta-blockers, several pharmacologic medications are reported for the prevention of AF such as ascorbic acid and other antioxidants [8-10].
In this study, we aimed to compare lipid peroxidation product malondialdehyde (MDA) levels and glutathione (GSH) levels in patients with coronary heart disease before and 24h after CABG surgery.
Materials and Methods
Materials
All chemicals used in this study were analytical grade and were obtained from Sigma (Sweden) and Merck (Germany).
Subjects
Fifty patients with CHD participated in this study. The study was approved and performed under the guidelines of Ethics Committee of Shiraz University of Medical Sciences. Informed consent was obtained from each subject before blood sampling.
Fifty patients (30 men and 20 women) with CHD referred to Namazi and Faghihi Hospitals were enrolled in this study. The inclusion criteria included patients with atherosclerotic triple vessel disease nominated for elective CABG without major surgical risk factors or abnormal biochemical investigations. All patients aged 40 to 50 years old with negative history of antioxidant supplementation consumption and their weight were 75±5 kg. Patients with previous history of rheumatoid arthritis, asthma and autoimmune diseases were excluded from the study.
For evaluation of oxidative stress, 3ml whole blood was taken before and 24 hours after surgery, MDA was measured by thiobarbituric (TBA) method and GSH was evaluated by colorimetric method.
Sample Processing
Blood samples were drawn into EDTA anticoagulant tubes and were centrifuged within 4 hrs after sampling. Plasma samples were immediately frozen and kept at −20°C for analysis.
Measurement of Plasma Total Glutathione
The assay of GSH with 5-5’-dithiobis[2-nitrobenzoic acid] (DTNB) was performed and followed by a standard Ellman’s method [11]. The standard curve was generated using a 1mM solution of GSH. Clear plasma was analyzed for GSH levels. Moreover, 2.3ml of potassium phosphate buffer (0.2 M, pH 7.6) was added to 0.2ml of plasma samples, followed by the addition of 0.5 ml DTNB (0.001 M) in a buffer. The absorbance of reaction products was observed after 5min at 412nm.