Increase of serum angiotensin-converting enzyme level after exposure to cigarette smoke and nicotine infusion in dogs.

Smoking is known to have various effects on metabolic function as well as on the respiratory function in the lung. We report here that exposure to smoke causes a rapid elevation of the level of serum angiotensin-converting enzyme in dogs in vivo. In 7 dogs, the level of serum angiotensin-converting enzyme increased from a basal level of 11.0 +/- 5.0 to 13.9 +/- 4.0 U/ml after 60 min of exposure (mean +/- SD, p less than 0.01). A similar elevation of serum angiotensin-converting enzyme level was noted in dogs that received an intravenous administration of nicotine. The possible mechanism of the change is discussed.