Thiourea induces DNA repair synthesis in primary rat hepatocyte cultures and gene mutations in V79 Chinese hamster cells.

Thiourea was investigated for its capacity to cause DNA alterations in cultured mammalian cells. The induction of DNA repair in primary rat hepatocyte cultures and of gene mutations in V79 Chinese hamster cells were used as biological endpoints. In hepatocytes, thiourea elicited a linear increase in DNA repair replication in the concentration range tested (5-25 mM). In V79 cells, thiourea (10-40 mM) significantly increased the frequency of 8-azaguanine-resistant mutants. The present results show that thiourea is weakly, but definitely, genotoxic and mutagenic in cultured mammalian cells.