Cigarette smoke causes acute fluctuations in the cyclic GMP content of the isolated intact lung.

The injection of a single bolus of the gas phase of cigarette smoke into the airway of an isolated, perfused and ventilated, canine lung preparation resulted in a sevenfold increase in lung cyclic GMP content by 2 s after exposure. Recovery of control levels occurred by 2 min after injection. Repeated smoke exposures of the same lung resulted in similar increases. These results indicate that cigarette smoke may activate lung guanylate cyclase when delivered through the airway and suggest that lung cyclic GMP levels may fluctuate acutely during smoking.