[Evaluation of the genotoxicity of vincristine and colchicine using mouse lymphoma tk mutation assay].

Objective: To evaluate the genotoxicity of two mitotic inhibitors vincristine and colchicine, and to compare the detecting sensitivity of tk gene mutation assay with short-and long-term treatment by them.

Methods: Tk gene mutation assay was performed by microwell method with L5178Y mouse lymphoma cell line after exposing to vincristine and colchicine for 3 h and 24 h respectively, and the results of two different treating time were compared.

Results: The two chemicals didn't show positive responses in mouse lymphoma assay (MLA) with 3h treatment, but they could induce tk mutation frequency increase 1.6 to 4.8 and 2.1 to 6.2 times higher to spontaneous MF respectively after continuous treatment for 24 h.

Conclusion: Vincristine and colchicine had mutagenic effect on tk gene with long-term treatment, which indicated that the detecting sensitivity of MLA could be enhanced by long-term treatment.