Smoking-induced alterations in platelet membrane fluidity and Na+/K+-ATPase activity in chronic cigarette smokers

Aim: cigarette smoking is a recognized risk factor for cardiovascular diseases and has been implicated in the pathogenesis of atherosclerosis. platelet adhesiveness and aggregation increases as a result of smoking. cigarette smoking modifies haemostatic parameters via thrombosis with a consequently higher rate of cardiovascular events,but smoking-induced alterations of platelet membrane fluidity and other changes have not been studied. methods: thirty experimental and control subjects (mean age 35±8) were selected for the study. experimental subjects had smoked 10±2 cigarettes per day for 7-10 years. the plasma lipid profile,platelet carbonyls,sulfhydryl groups,na+/k+-atpase activity,fluidity using a fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (dph),total cholesterol and phospholipids as well individual phospholipids were determined. results: increases in the platelet membrane cholesterol phospholipid (c/p) ratio,phosphotidylethanolamine,phosphotidylserine with decreased phosphotidylcholine,na+/k+-atpase activity,fluidity and no significant change in phosphotidylinositol and sphingomylein,as well as increases in plasma total cholesterol,ldl-cholesterol,protein carbonyls with decreased hdl-cholesterol and sulfhydryl groups were observed in cigarette smokers. platelet membrane total phospholipids were positively correlated with plasma ldl-cholesterol (r = 0.568) and vldl-cholesterol (r = 0.614) in cigarette smokers. conclusions: increased plasma ldl-cholesterol,vldl-cholesterol and total cholesterol might have resulted in the increased c/p ratio and decreased platelet membrane fluidity of cigarette smokers.