Chromosomal aberrations induced by maleic hydrazide and related compounds in Chinese hamster cells in vitro

Abstract

The cytotoxic effects and chromosomal abnormalities induced by maleic hydrazide (MH) and its salts were investigated in cultured V79 cells. MH, and its potassium (K-MH) and diethanolamine (DEA-MH) salts were tested. MH was 5–14 times more cytotoxic than its salts and almost 4.5 times less toxic than the related compound, hydrazine dihydrochloride (HDC). MH salts had very weak cytotoxicity; the LD 50 values on V79 cells on exposure for 3 h in vitro were (in μg/ml) 1100 (MH), 12 000 (DEA-MH), 20 000 (K-MH), 230 (HDC) and 10 000 (NaCl). Both MH and its salts — but neither HDC nor NaCl — caused chromosomal aberrations in cultured V79 cells. The maximal frequencies of aberrant cells in cultures exposed to the compounds for 3 h in vitro were 18% (MH at 1000 μg/ml), 18% (K-MH at 20 000 μg/ml) and 13% (DEA-MH at 20 000 μg/ml). Maximal frequencies observed in cultures treated with HDC or NaCl were 10% (HDC at 400 μg/ml) and 5% (NaCl at 10 000 μg/ml). Those of positive groups were 97% ( N-methyl- N′-nitro- N-nitrosoguanidine, MNNG, at 5 μg/ml) and 16% (ethyl methanesulfonate, EMS, at 400 μg/ml). These frequencies of MH and its salts were 3.25–4.5 times those in untreated control cells. These results suggested that MH and its salts had weak inducibility of cytotoxicity and positive cytogenetic effects on V79 cells in vitro.