Effect of malonaldehyde and acetaldehyde on cultured mammalian cells: Growth, morphology, and synthesis of macromolecules.

Primary cultures of rat skin fibroblasts were used as a model system to investigate the biological effects of the lipid peroxidation product malonaldehyde (MA). Acetaldehyde (AA) was used as a reference compound. Cells exposed to 10-3 M MA for 120 h exhibited altered morphology, cytoplasmic vacuolization, karyorrhexis, micro- and multinucleation, and a marked reduciton in mitotic index and DNA-, RNA-, and protein-synthesizing capacity. At 10-4 M, MA also caused mitotic aberrations, micronucleation, and a reduction in mitotic index and DNA synthesis. At 10-5 and 10-6 M, MA induced only the formation of small and irregular nuclei. Acetaldehyde at 10-3 M had similar but less severe effects on nuclear morphology, mitotic index, and macromolecule synthesis. At 10-4 M AA, only mitotic aberrations and nuclear changes were observed. At 10-5 and 10-6 M, AA exerted no apparent effects on either the structure or anabolic activity of the cells. With respect to antimitotic activity, MA was approximately 10 times as toxic as AA.