Inducible protective processes in animal systems XIV: Cytogenetic adaptive response induced by EMS or MMS in bone marrow cells of diabetic mouse

Abstract

Background: Adaptive response has been well studied by employing physical and chemical agents in normal test systems, whereas in diseased conditions very little data are available.

Aim of the study: To know the presence or absence of adaptive response in diseased condition, alkylating agents such as EMS or MMS have been employed in diabetic mouse.

Material and methods: To induce diabetes, mice were injected with 180 mg/kg body weight of Stz. Diabetic mice were treated with conditioning (100 mg/kg body weight of EMS or 40 mg/kg body weight of MMS), challenging (300 mg/kg body weight of EMS or 160 mg/kg body weight of MMS) and combined doses of EMS or MMS with 8 h time lag. Parallelly controls were maintained. Mice were sacrificed at 24 or 48 or 72 h RTs. Bone marrow was extracted and slides were prepared by a routine air dry technique by Evans et al. (1964) to analyze the chromosomal aberrations.

Results: The results show that both the alkylating agents induced exclusively chromatid type of aberrations in both diabetic and non diabetic mice, but it is to be underlined that MMS is a more potent inducer of aberrations than EMS. Eventhough, combined treatment of EMS or MMS induced significantly less chromosomal breaks compared to challenging treatment (p< 0.05) in diabetic mice, EMS induced 40% reduction of breaks, compared to 51.74% by MMS at 24 h RT. This is true to other tested RTs.

Conclusion: (1) Methylating agents are a more effective inducer of adaptive response than ethylating agents in diabetic mouse. (2) Further, it is interesting to note that the percentage reduction of chromosomal breaks in diabetics is comparatively much less than in non diabetic mouse, inferring that there is variation in adaptive response between diseased and non diseased condition.

Keywords: EMS; MMS; Adaptive response; Chromosomal aberrations; Diabetic mouse; Conditioning dose; Challenging dose; Combined dose