Peroxisome proliferation in neoplastic nodules and hepatocellular carcinomas induced by ciprofibrate in the rat.

Neoplastic nodules (NN) and hepatocellular carcinomas (HCC) induced in the rat by ciprofibrate were analyzed for peroxisome proliferation. The volume density of peroxisomes in NN and HCC was 5.7 +/- 2.7 and 6.6 +/- 2.9, respectively; whereas in adjacent uninvolved liver the volume density was 16.3 +/- 5.0. No ultrastructural differences between NN were found to discriminate nodule from carcinoma. The results of this study indicate that the peroxisome proliferative response of NN and HCC to ciprofibrate is similar and can not be used as a marker to differentiate these lesions.