Effect of CPT‐11 on Lipid Peroxide Level in Mouse Tissues

We examined the effects of CPT‐11 on lipid peroxide level and glutathione peroxidase (GSHpx) activity as indices of the toxicity of this antitumor agent in mouse and rat tissues. After CPT‐11 (100 mg/kg, i.p.) administration, the lipid peroxide level in the heart increased 1.5 fold (mice) and 1.3 fold (rats) over the control levels. GSHpx activity decreased to 64% of the control. In the lung, the lipid peroxide level and GSHpx activity increased 2.5 fold and decreased to 74% after CPT‐11 administration, respectively, compared with the control values. These results suggested that CPT‐11 may cause cardiotoxicity and pulmotoxicity. In rat hone marrow, the lipid peroxide level increased on the 2nd day after CPT‐11 injection. We suggest that in both single and combination treatment with CPT‐11, the possibility of side effects should be taken into consideration.