Objective To study the toxicity mechanism(s) of
cyclophosphamide (CP) and ifosfamide (Ifo) on suspending cultured rat
hepatocytes.Methods
Hepatocytes of adult rat were isolated by two-step perfusion method and cultured suspendingly. Cell viability, intracellular enzymes leakage, contents of sulfhydryl groups and MDA content of hepatocytes were detected 30,60,120 and 180 minutes after CP and Ifo were administered at 20 mmol/L respectively.Surface morphology and ultrastructure of hepatocytes were also observed.Results Cell viability and total sulfhydral group (TSH), non-protein-bound sulfhydral group (NPSH), protein-bound sulfhydral group (PSH) contents of hepatocytes declined significantly, and LDH, AST activities in media increased due to the leakage of intracellular enzymes. These changes were all time-dependent. The decrease of PSH content was ascribed to TSH's depletion. However, MDA contents of the hepatocytes were not found increased at any dose of CP and Ifo.There was little difference between the toxicity of CP and Ifo statistically. In morphological examination, “bulla” formation was found on the surface of the hepatocytes, deformation, swelling, even vacuolation of mitochondria and dilation of rough endoplasmic reticulum were also observed 180 min after the administration in both CP and Ifo treated groups.Conclusion CP and Ifo have toxic effects on suspending cultured rat hepatocytes. The decrease of sulfhydryl groups contributes to the hepatotoxicity induced by both chemicals.