Inducible protective processes in animal systems: IV. Adaptation of mouse bone marrow cells to a low dose of ethyl methanesulfonate

Ethyl methanesulfonate (EMS), a monofunctiona) alkylating agent,was used in the present investigations to investigate the inductionof adaptive response (inducible protective processes) in mitoticcells of Swiss albino mouse. When a low (conditioning) doseof 80 mg/kg body wt was challenged with a subsequent high (challenging)dose of 240 mg/kg body wt, after different time lags, the yieldof chromosomal aberrations in bone marrow cells was found tobe significantly reduced compared with that of the challengedose. It appears, therefore, that a low dose of EMS offeredresistance to the mitotic cells against further dastogenic effectof any challenge dose of EMS employed. It is clear from theresults that the phenomenon of adaptive response can also beencountered in mammalian in vivo systems. ¹To whom correspondence should be addressed