Comparative lung pathology of rats after exposure to cigarette and cigar smoke.

In a series of 3 experiments, rats bred and maintained under minimum disease conditions suffered much less lung damage after exposure to cigar smoke than did similar animals exposed to the smoke of Virginia tobacco. Rats exposed to cigar tobacco smoke also showed a greater weight gain and a lower acute-phase protein increase than did their Virginia tobacco counterparts. These differences in response were compounded by the results obtained from measuring changes in the epithelium of the intrapulmonary airways. The smoke of air-cured but not fermented cigar tobacco had an effect similar to the smoke of Virginia tobacco.

Buffering capacity of the smoke of different tobaccos in relation to lung cancer risks.

A method of assessing "buffering capacity" is described for comparison of the degree of acidity of alkalinity of the smoke of different tobaccos as presented to the oral and respiratory tracts of the smoker. Nicotine is more readily absorbed from an alkaline than from an acid smoke. The smoker of tobaccos giving a smoke of acid buffering capacity, in order to achieve full nicotine satisfaction, tends to smoke more and to inhale more, thus increasing lung cancer risks, than the smoker of tobaccos giving smoke of less acid or of alkaline buffering capacity.