Cigarette smoke-induced elevation of plasma neuropeptide Y levels in man.

The purpose of the present study was to evaluate whether neuropeptide Y, which coexists with noradrenaline in sympathetic nerves, may be released upon cigarette smoking. Therefore, previously non-smoking adults inhaled smoke from one cigarette once every minute during 10 min, and the effects on blood pressure, heart rate and plasma levels of noradrenaline and neuropeptide Y were analysed. A prompt rise of systolic blood pressure and heart rate (by 25 mmHg and 30 beats min-1, respectively) was observed upon smoking. Systemic plasma levels of noradrenaline and neuropeptide Y were significantly elevated after 3 and 5 min of smoking, respectively, and reached maximal values (neuropeptide Y from 32 +/- 4 to 49 +/- 7 pmol l-1, and noradrenaline from 0.72 +/- 0.16 to 1.8 +/- 0.44 nmol l-1) 2-5 min after the smoking period. It is concluded that smoking in man is associated with increased plasma levels of both noradrenaline and neuropeptide Y, suggesting release of these agents. Since neuropeptide Y is a potent vasoconstrictor, the present data suggest that this peptide may contribute to the smoke-induced cardiovascular response.