Cytogenetic effects of N-nitrosodiethanolamine (NDELA) and NDELA-monoacetate in human lymphocytes.

The mutagenicity of N-nitrosodiethanolamine (NDELA) and NDELA monoacetate was tested in vitro on lymphocytes of two healthy probands by determining the frequencies of chromosome aberrations, micronuclei and sister chromatid exchanges (SCE). A dose-dependent increase was found in all three test systems for NDELA as well as its monoacetate. The SCE test proved to be most sensitive for the genotoxic effect of NDELA because the differences to the control cultures had already become significant at 250-625 mumol/culture (26.6-65.4 mM). However, NDELA monoacetate showed a higher reactivity in the micronuclei and chromosome aberration test: significantly increased values were found even at 12.5 mumol (1.3 mM), whereas in the SCE test the differences became significant at the 25-mumol (2.7 mM) level. NDELA caused significantly increased rates of micronuclei and chromosome aberrations only at the highest test levels (625-1250 mumol; 65.4-127.6 mM). The results indicate important differences in the genotoxic effects of the two compounds, which might be explained by different lipophilicity and/or special activation processes.