Objective The present study was undertaken to investigate the differences of the hepatotocixity induced by Cyclophosphamide(CP)and
its isomeric analogue ifosfamide(IFO).Methods The
contents of malondialdehyde(MDA),sulfhydryl groups and micriosomal cytochromes(Cyt P450) of live tissue and biochemical indexes of serum in rats exposed at doses of 40 mg/kg CP and IFO for 5 days after treatment 1、4、7 and 10 hr.Results The biochemical indexes of serum and contents of MDA of liver tissue didn't change significantly in both treated goups,while total,nonprotien, protienbound sulfhydryl and cyt P450 contents of liver tissue were declined the decreases of protenbound sulfhydryl were associated with total sufhydryl's depletion.However,the extents of these
changes caused by both drugs were different.The changes of Cyt P450 contents were similar to those of suifhydryl groups.The decreases of Cyp P450 contents were 19 2%、26 8%、61 1%、15 2% on day 1、4、7 and 10 in group treated with cp,respectively,while in group treated with IFO it was 20 7% and 40 2% only on day 1 and 7.Conclusion The results indicated that the changes of sulflydryl and Cyt P450 contents of live the induced by CP were difference from IFO.The difference of the hepatotoxicity between CP and IFO probably was caused by the metabolic difference of both drugs.