Hormonal effects of smoking--I: Effects on plasma renin activity

It is generally recognized that smoking is associated with an increased risk for the development of coronary artery disease. Since it has been suggested that increased plasma renin activity (PRA) may be a risk factor for cardiovascular disease, PRA was measured in a group of smokers and nonsmokers. PRA was measured under basal conditions, following intravenous (IV) furosemide administration and after a short burst of smoking. In addition, the effect of nicotine on renin secretion was evaluated in vitro. Smoking was associated with a significant increase in pulse rate and systolic blood pressure, but no significant change in diastolic blood pressure in both groups. Basal PRA was similar among smokers and was not significantly influenced by smoking in either group. PRA increased significantly following IV administration of furosemide, but there was no significant difference between the two groups. Incubation of rat kidney slices with nicotine also did not result in increased renin secretion. These findings confirm that smoking affects the cardiovascular system, but no significant effect of smoking on PRA was observed both in vivo and in vitro experiments. These findings suggest that the increased risk for the development of coronary artery disease associated with smoking is not mediated by increased PRA.