Production of chromosome pulverization specially associated with the effect of post-treatment with caffeine after treatment with different classes of clastogens in chinese hamster V79 cells.

The effect of post-treatment with caffeine on chromosomes was examined in Chinese hamster V79 cells pretreated with different classes of clastogens.The clastogens tested were ultraviolet light (UV), 4-nitroquinoline 1-oxide (4NQ0), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and mitomycin-C (MMC).The most striking effect of caffeine was to enhance production of chromosome pulverization.This enhancing effect was observed with each clastogen, only when they were combined with caffeine.Caffeine itself did not produce pulverizations under the conditions tested.Among the clastogens examined, MMC was the most potent inducer for pulverization followed by UV and 4NQ0, while MNNG induced scarecely any.With increase in pulverized chromosomes, other types of aberrations, such as exchanges, were reduced in most cases, except with MNNG.The total aberrations (pulverizations and other aberrations) were increased in all cases by post-treatment with caffeine.