In vitro effect of nicotine and cotinine on the susceptibility of LDL oxidation and hemoglobin glycosylation.

Nicotine, a major component of cigarette smoke, plays an important role in the development of cardiovascular disease and lung cancer in smokers. This study was designed to determine the in vitro effects of nicotine and its metabolite cotinine on the susceptibility of LDL to oxidation and hemoglobin glycosylation. Three different concentrations of each one (10, 15, 25 microg/ml) were used. Our data show that nicotine and cotinine are inhibitors for Cu(2+)-induced LDL oxidation but also they increase the glycosylation degree of hemoglobin. Nicotine at final concentrations of (10, 15, 25 microg/ml) increases the rate of hemoglobin glycosylation 25, 32 and 47%, respectively, and cotinine at final concentrations increase the rate of glycosylation 8, 10 and 12%, respectively. Therefore promoting hemoglobin glycosylation is one of the alternations caused by smoking that increase risk of cardiovascular disease.