Effect of Tobacco Smoke on the Metabolism of Rat Lung

Abstract

The authors have studied the effect of cigarette smoke on the uptake and metabolism of ³H–palmitate, ³H-leucine, U¹⁴ C–glucose and ¹⁴C-glucosamine utilizing slices of rat lung. The rats were exposed daily for 30 days to University of Kentucky research cigarettes (brands 1A1 or 1R1) in the Walton smoking machine. One group of rats served as intact controls and another were introduced into the machine, but were not exposed to smoke. All animals were weight-matched at the beginning of the experiment (180 ± 5 g); machine control rats gained 25% less weight, 1A1-exposed rats 40%; and 1R1-exposed rats 2640% less than controls. Exposure to tobacco smoke had no effect on palmitate uptake and synthesis of phospholipids; exposure to 1A1 cigarettes caused a 25% increase in ¹⁴C0₂ production and a 30% higher incorporation of glucose into lipids. Exposure to 1R1 cigagrettes had no effect on glucose metabolism. Protein synthesis was 30% lower in 1R1-exposed rats and glycoprotein synthesis increased two-fold in both 1A1 and 1R1 exposed rats.