Nitric Oxide Levels in Smokers and Nonsmokers

Endothelial cells by secreting continously nitric oxide (NO), endothelial cells regulate both vascular tone and blood pressure, and suppress thrombocyte adhesion and aggregation. In addition, it is determined that they suppress the increase and migration of vein smooth muscle cells. Smoking cigarette causes functional disruptions in endothelial cells, and leads to a reduction in NO activity. The aim of this study was to investigate the effect OF smoking cigarettes on aggregation, thrombocyte adhesion and plasma NO level. 101 volunterering cases, aged 24-47 years, not subjected to any medication during the past week and having no health problem, were included in the study. The patients were classified into 3 groups. The first group (Group I, n:40) comprised 'heavy smokers with a smoking history of >20 cigarettes per day. The second one (Group II, n:38) consisted of 'moderate smokers' with a smoking history of >10-20 cigarettes per day. 23 nonsmokers were accepted as a control group (Group III). Venous blood from the cases was injected after 15-minuter est following a 12-hour hunger period and 24-hour period without smoking. From this blood, the level of NO, thrombocyte aggregation and thrombocyte adhesivity was measured. Serum NO concentration in group I was 12.05 ± 2.83 µM, and was 13.98 ± 2.52 µM in group II, while it measured 18.69 ± 9.91 µM in group III. NO concentrations in both group I and group II were significantly lowered as compared to that of group III (respectively p<0.001, p<0.01). In addition, NO concentration in group I was significantly lowered than of that of group II (p<0.05). Although there were slight distinctions among groups in regard to thrombocyte adhesivity and aggregation, they did not differ significantly (p>0.05). Consequently, we concluded that NO level is diminished in smokers, more prominently among heavy smokers; but thrombocyte aggregation and adhesivity in ex vivo circumstances, does not appear to be affected by smoking.