Smoking-induced alterations in platelet membrane fluidity and Na(+)/K(+)-ATPase activity in chronic cigarette smokers.
OBJECTIVE
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.
Department of Biochemistry, Sri Krishnadevaraya University, Anantapur -515 055, AP, India.
Pannuru
P
Padmavathi
Vaddi Damodara
VD
Reddy
Paramahamsa
P
Maturu
Nallanchakravarthula
N
Varadacharyulu
D000328:Adult; D001792:Blood Platelets / Q000473:pathology*; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D015243:Cholesterol, VLDL / Q000097:blood; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008560:Membrane Fluidity; D010743:Phospholipids / Q000097:blood; D012907:Smoking / Q000009:adverse effects* / Q000097:blood; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D008078:Cholesterol, LDL; D015243:Cholesterol, VLDL; D008055:Lipids; D010743:Phospholipids; D002784:Cholesterol; D000254:Sodium-Potassium-Exchanging ATPase