Biochemical and immunological characterisation of mutants induced in V79 Chinese hamster cells by a benzo[a]pyrene diolepoxide

A series of 8-azaguanine resistant mutants was induced by treatmentof V79 Chinese hamster cells with either r-7,t-8-di-hydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene(anti-BPDE) or methyinitrosourea (MNU). Hypoxanthine phos-phoribosyitransferase(HPRT) activity in the mutants was determined for both hypoxanthineand azaguanine as substrates. With antiserum to purified brainHPRT, cross-reacting material was also determined and analysedby two dimensional polyacrylamide gel electrophoresis. By thesecriteria mutants induced by anti-EPDE or MNU did not differappreciably and the data obtained was consistent with the inductionof point mutations by both carcinogens. The relevance of theseresults to the correlation of carcinogencity with mutagenicityin V79 cells, but not in bacteria, is discussed.