Reduction in Nitric Oxide metabolites and antioxidants concentration in plasma after a single Cigarette smoking

In this study, the changes in the combined plasma concentrations of nitrate and nitrite as an index of nitric oxide [NO] concentration as well as the changes in the concentrations of major serum antioxidants [ascorbic acids and methionine] in smokers after smoking a single cigarette were measured. The effect of smoking a single cigarette was studied in 30 smokers and 15 nonsmokers [controls]. Plasma were collected before 5 and 60 minutes after smoking a single cigarette to measure the plasma levels of NO metabolites and antioxidants. Smoking a single cigarette significantly decreased NO metabolites concentrations by 10.2 +/- 1.1 mumol/L compared with the plasma concentrations at pre-smoking [13.5 +/- 1.2 mumol/L. The concentrations of ascorbic acid and methionine were also significantly lower after smoking a single cigarette [39.7 +/- 3.3 mumol/L and 8.1 +/- 0.7 mumol/L, respectively] compared with the plasma concentrations at pre-smoking [51.8 +/- 4.2 mumol/L and 10.2 +/- 0.7 mumol/L, respectively, for both]. These parameters returned to the pre-experimental levels at 60 minutes after smoking cessation. In nonsmokers, the same results were obtained, except that the impairments of NO and antioxidant release from the endothelium are less than in nonsmokers

Effects of cigarette smoking and its cessation on body weight and plasma leptin levels in old male

To determine whether the weight reducing effect of cigarette smoking is mediated by leptin, fasting leptin levels in 22 male smokers [mean age 62 +/- 1 year] and 22 non-smoker males [mean age 64 +/- 1 year] with an age average of 60-65 years for both groups were measured. Mean body mass indices were 27.61 +/- 0.7 and 27.6 +/- 0.07 kg/m2, respectively. Mean leptin levels were 8.4 +/- 1.3 and 5.2 +/- 0.6 ng/ml, respectively. Smokers had a significantly higher leptin levels than nonsmokers. Fasting leptin levels and BMI were re-measured in 13 smokers who successfully gave up smoking for 6 months. Although body weight and BMI significantly increased after six months of smoking cessation, the mean leptin level did not decline significantly. These findings suggested that cigarette smoking directly elevates circulating plasma leptin concentration and this increase may be one of the mechanisms for lowering body weight of smokers in comparison with nonsmokers. However, the effect of cigarette smoking on body weight does not appear to be directly due to the changes in leptin level as evidenced by an insignificant difference between leptin levels in smokers and ex-smokers. Other factors such as hormones involved in body weight regulation and influencing the weight gain after cessation of cigarette smoking should be investigated