Influence of Cigarette Smoke on Guinea Pigs

Abstract
A significant increase in the number of polymorphonuclear leukocytes recoverable from the lungs of guinea pigs has been demonstrated to occur in response to exposure to cigarette smoke. This increase was accompanied by no change in serum antitrypsin levels over the ten-week exposure period. These observations., if applicable to man, suggest that a source of proteolytic enzymes in relatively high concentrations may be continuously present in the lungs of cigarette smokers. The depressant effect of cigarette smoke on natural respiratory defenses leaves the system increasingly susceptible to bacterial infections and even greater inflammation results. When this is added to an already excessive number of leukocytes chronically present, the resultant concentration of proteolytic enzymes may be greater than can be counteracted by the available enzyme inhibiting agent.