Norepinephrine and Epinephrine Release and Adrenergic Mediation of Smoking-Associated Hemodynamic and Metabolic Events

We studied the effects of cigarette smoking, sham smoking and smoking during adrenergic blockade in 10 subjects to determine whether smoking released the sympathetic neurotransmitter norepinephrine, as well as the adrenomedullary hormone epinephrine, and whether smoking-associated hemodynamic and metabolic changes were mediated through adrenergic mechanisms. Smoking-associated increments in mean (S.E.M.) plasma norepinephrine (22723 to 32439 pg per milliliter, P< 0.01) and epinephrine (444 to 11327 pg per milliliter, P< 0.05) were demonstrated. Smoking-associated increments in pulse rate, blood pressure, blood glycerol and blood lactate/pyruvate ratio were prevented by adrenergic blockade; increments in plasma growth hormone and cortisol were not. Since significant smoking-associated increments, in pulse rate, blood pressure and blood lactate/pyruvate ratio, preceded measurable increments in plasma catecholamine concentrations, but were adrenergically mediated, these changes should be attributed to norepinephrine released locally from adrenergic axon terminals within the tissues rather than to increments in circulating catecholamines. (N Engl J Med 295:573-577, 1976). Acute coronary-heart-disease events — acute myocardial infarction or sudden death in patients with coronary-artery disease — are among the disorders strongly associated with cigarette smoking.₁Although it has been suggested that smoking may contribute to the development of coronary atherosclerosis per se, several epidemiologic observations suggest the alternative possibility that cigarette smoking triggers acute coronary-heart-disease events in patients with underlying coronary-artery disease. These observations include: Doyle's finding that smoking was a weak independent risk factor but greatly increased the probability of acute coronary events in patients with hypertension or hypercholesterolemia₂; the finding that men who were former smokers on.