Deposition and clearance of 14C-labelled cigarette smoke particles in Syrian hamster respiratory and digestive tract.

Eight week old male and female Syrian golden hamsters inhaled smoke of Dotriacontane-16, 17- 14C-labelled research cigarettes. The investigation consisted of 4 experiments and each experiment involved 4 groups of 10 animals each. Eighty of the animals (40 males: 40 females) were killed immediately after exposure to the 14C-labelled smoke of 30 cigarettes (10 uCi/cigarette) and the organs of the respiratory and digestive tract were measured for their 14C-activity. Non-acclimatized Syrian golden hamsters inhaled quantitatively more condensate/g organ weight than acclimatized animals. There was no difference between males and females. Nearly 50% of the retained 14C-activity was found in the digestive tract, half of the amount was in the forestomach. The distribution in the respiratory tract showed no difference between acclimatized and nonacclimatized animals. More than 75% of the measured activity in the total respiratory tract was found in the lung. The highest concentration was measured in the lobus dexter caudalis and lobus sinister. The clearance of the lung was slower in acclimatized hamsters than in non-acclimatized animals. When animals inhaled the smoke of labelled cigarettes for five days the clearance of the lung was slower in acclimatized hamsters than in non-acclimatized animals.