Pancreatic elastase and serum alpha 1-antitrypsin levels in beagle dogs smoking high- and low-nicotine cigarettes: possible mechanism of pancreatic cancer in cigarette smokers.

Beagle dogs exposed to cigarette smoke for 600 d experience a significant change in pancreatic elastase levels, as measured in tissue homogenates, compared with their sham-exposed controls. Greater elastase activity was found in the high-nicotine cigarette smokers than in the low-nicotine cigarette smokers. Levels of serum alpha 1-antitrypsin, an antiprotease capable of complexing the excess elastase, were also investigated. Animals smoking high-nicotine cigarettes had significantly lower serum alpha 1-antitrypsin activities than controls. Low-nicotine smokers showed alpha 1-antitrypsin activities that were not significantly different from those of controls. The importance of these observations is reinforced by a number of studies suggesting that proteases, their inhibitors, and an imbalance thereof may be related to the onset of neoplastic lesions. Studies have indicated that antiprotease levels follow the patterns of Mendelian inheritance. Severe deficiency states predispose human subjects to emphysema. A similar relationship may exist between antiprotease levels and susceptibility or resistance to neoplasms of the pancreas, a concept that deserves investigation in light of the findings reported here.