Cigarette smoke—A proposed metabolic lesion in alveolar macrophages

Abstract

The effects of the filtered gas phase of cigarette smoke were investigated with respect to certain enzyme activities of rabbit alveolar macrophages. Preliminary experiments with crystalline preparations of glyceraldehyde 3-phosphate dehydrogenase showed that cigarette smoke is a potent inhibitor of this enzyme and that protection from inhibition by smoke is afforded by cysteine. Other experiments, in which enzyme activity was measured in alveolar macrophages, demonstrated inhibition of glyceraldehyde 3-phosphate dehydrogenase activity in cells treated with cigarette smoke and protection by cysteine. There was no significant impairment of the activities of glucose 6-phosphate dehydrogenase and lactic dehydrogenase in smoke-treated macrophages. Histochemical evidence supported these findings. It is suggested that a relationship exists between loss of alveolar macrophage phagocytic competence and inhibition of glyceraldehyde 3-phosphate dehydrogenase. This paper discusses impaired phagocytosis by macrophages in the presence of cigarette smoke in relation to concomitant reduction in glyceraldehyde 3-phosphate dehydrogenase activity.