Cigarette smoke inhalation and blood dose markers in beagle dogs

The time course of three tobacco-related blood dose markers was determined in beagle dogs during and after two-, four-, and six-cigarette acute smoke exposures. Venous blood samples were taken from a jugular catheter at selected intervals and analyzed for nicotine, cotinine, and carboxyhemoglobin (COHb). Smoke was generated from reference cigarettes (1.91 mg of nicotine) by a machine and delivered to the trachea of tracheostomized dogs. Cigarettes were chain-smoked in pairs with a 5-min break between pairs when four or six cigarettes were smoked. Blood nicotine, cotinine, and COHb levels all rose during smoke inhalation. Peak values of COHb were dosimetrically related to the number of cigarettes, while peak nicotine and cotinine values were not related consistently. The exposure protocol used in this study produced blood levels of all three measured parameters which were in the range of published values for human smokers, so that it is possible to approximate acute human cigarette smoke inhalation in the beagle dog model.