Changes in Liver Cytoplasmic Glutathione-S-Transferase and Microsomal Nitrosodimethylamine Demethylase Activities in Chicks Obtained Following Daminozide Treatment


Abstract: In this study, microsomal nitrosodimethylamine demethylase (NDMAd) and cytoplasmic glutathione-s-tarnsferase (GST) activities in the livers of chicks obtained from the LD 10 (3 mg/ml) and LD 30 (9 mg/ml) doses of daminozide (Succinic acid 2,2-Dimethylhydrazide) injected Ross-Pm-3 fertilized chicken eggs were investigated. Spectrophotometric determination of NDMAd activity was performed at 412 nm by the detection of yellow coloured compound formed as a product of the reaction of formaldehyde with Nash reagent. No significant increase was observed in NDMAd activity (P>0.05) of the group treated with LD 10 dose although NDMAd activity was found to be significantly increased (P<0.05) in the gro up treated with LD 30 dose of daminozide. GST enzyem was purified by affinity chromatography and GST activity was determined by following the formation of thioester linkage between GSH and (1-Chloro-2,4-dinitrobenzene) CDNB at 340 nm. Specific and total GST activities were given as µmol/mg min. and unite, respectively. GST activties of the groups treated with LD 10 and LD 30 doses of daminozide were found to be decreased (P<0.05) when compared with those of the control group. In conclusion, LD 30 dose of daminozide led to the induction of NDMAd enzyme activity while LD 10 and LD 30 doses was shown to inhibit GST enzyme activity. The changes it these enzyme activities could lead to the insufficiency of the detoxification process.

Keywords: Daminozide, Nitrosodimethylamine Demethylase, Cytochrome P-450IIE1 Glutathione-S-Transferase.

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