Cigarette smoke induced changes in rat pulmonary clearance of 99mTcDTPA. A comparison of particulate and gas phases.

The rat model was developed to study the effects of cigarette smoke on pulmonary clearance of 99mTcDTPA. The method developed was sufficiently noninvasive to allow frequent repeat measurements to be made with a high degree of reproducibility. Animals exposed twice daily to 90 puffs of dilute whole cigarette smoke for 7 days showed an increase in 99mTcDTPA clearance from the lung which returned to normal within 3 wk of stopping exposure. Filtration of the smoke to remove all the particulate matter abolished the changes.