Effect of adenosine 3',5' monophosphate on the mutation frequency induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of increased cellular concentrations of adenosine 3',5' monophosphate (cAMP) upon mutation frequency induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied in V79 Chinese hamster lung cells. Incubation with either forskolin, which increased the accumulation of cAMP, or 8BrcAMP, an analogue of cAMP, resulted in an increase in the mutation frequency which was concentration-dependent, regardless of whether these agents were added before or after mutagen treatment. Increased cAMP concentrations were shown in these cells to inhibit growth; however, this does not seem to be the mechanism responsible for the increase in mutation frequency as low serum concentrations which also retard growth reduced the mutation frequency observed with MNNG.