The Incorporation and Localization of Aldehydes (Highly Reactive Cigarette Smoke Components) into Cellular Fractions of Cultured Human Lung Cells

Abstract Wl 38 human fetal lung fibroblasts were incubated with tracer amounts of 14C-labeled formaldehyde and acetaldehyde which are highly reactive components of cigarette smoke. A pulse of 10 min with formaldehyde followed by a 60-min and 24-hr chase showed migration of 14C label into the nucleus. Fractionation of the nucleus revealed that the RNA fraction had the highest absolute and specific activity while the DNA and protein fractions contained considerably lower activities. All of the counts from formaldehyde were found in the adenine and guanine components of RNA. The DNA counts were distributed among adenine, guanine, and thymine. Incubation with 14C acetaldehyde showed a majority of the counts localized in the membrane plus nuclear lipid fraction. A small proportion of counts was found in the protein portion of the cells.