SMOKELESS NICOTINE ADMINISTRATION IS ASSOCIATED WITH HYPERTENSION BUTNOT WITH A DETERIORATION IN GLUCOSE-TOLERANCE IN RATS

Cigarette smoking is a major risk factor for coronary heart disease, T o further investigate the relationship of nicotine with other cardiac risk factors, we studied the impact of nicotine on blood pressure and glucose tolerance. Adult male Sprague-Dawley rats were randomly assign ed to receive nicotine or placebo pellets implanted subcutaneously, We ight gain was controlled by pair-feeding, and was not significantly di fferent between nicotine-and placebo-treated animals. Blood pressure ( in mm Hg) increased throughout a 3-week treatment period in nicotine-t reated animals and was significantly higher (P<.05 by two-way ANOVA) t han in placebo-treated rats, Blood pressure returned to normal within 1 week following exhaustion of the pellets. Oral glucose tolerance tes ts performed 2,5 weeks after pellet placement showed similar glucose, insulin, and free fatty acid (FFA) profiles by two-way ANOVA. In summa ry, smokeless nicotine exposure leads to sustained but reversible hype rtension without deterioration in glucose tolerance or insulin action when weight gain is controlled, We conclude that in rats smokeless nic otine adversely affects the coronary risk profile by increasing blood pressure. Copyright (C) 1997 by W.B. Saunders Company.