Effect of malonaldehyde and acetaldehyde on cultured mammalian cells. Production of micronuclei and chromosomal aberrations.

The genotoxic effects of malonaldehyde (MA) and acetaldehyde (AA) were investigated using primary cultures of rat skin fibroblasts. Exposure to MA at 10(-4) to 10(-3) M concentrations resulted in dose-dependent production of micronuclei. MA was approx. 10 times as potent as AA with respect to micronuclei formation. Treatment with 10(-4) and 10(-3) M concentrations of MA for 12 h produced chromosomal aberrations (chromosomal fragments, achromatic lesions and chromatid breaks) in 14 and 34% of metaphases, respectively. At 24 h the corresponding frequencies were 46 and 52%. AA at analogous concentrations produced aberrations in 4 and 14% of metaphases at 12 h, and 20 and 40% at 24 h. Dose-dependent increases in aneuploidy were seen at 10(-4) M and higher concentrations of both aldehydes, with incidences twice as high for MA as for AA.