Factors influencing peroxisome proliferation in cultured rat hepatocytes

• Published in: Archives of toxicology Vol. 55; no. 4; p. 239
• Main Authors: Mitchell, A M, Bridges, J W, Elcombe, C R
• Format: Journal Article
• Language: English
• Published: Germany 01.10.1984
• Subjects: Animals; Carnitine - toxicity; Cell Division - drug effects; Cells, Cultured; Clofibric Acid - toxicity; Diethylhexyl Phthalate - analogs & derivatives; Diethylhexyl Phthalate - toxicity; Dose-Response Relationship, Drug; Glucosephosphate Dehydrogenase - analysis; Hydrocortisone - pharmacology; Liver - drug effects; Male; Microbodies - drug effects; Microbodies - metabolism; Palmitoyl Coenzyme A - metabolism; Rats; Rats, Inbred Strains; Trichloroacetic Acid - toxicity
• ISSN: 0340-5761
• DOI: 10.1007/BF00341018

A primary rat hepatocyte culture system has been developed for the study of peroxisome proliferation. Maximal induction of peroxisomal activity requires supplementation of the culture medium with hydrocortisone. The addition of clofibric acid (0.01-1 mM), mono-(2-ethylhexyl)phthalate (0.01-0.5 mM) and trichloroacetic acid (0.1-5 mM) to cultured rat hepatocytes resulted in a time- and dose-related increase in CN- insensitive palmitoyl CoA oxidation (maximal increases: 27-, 15.5-, and 5-fold respectively) and mitochondrial alpha-glycerophosphate dehydrogenase activity (maximal increases: 7.3-, 5.8-, and 1.6-fold respectively). Electron microscopic examination revealed smooth endoplasmic reticulum proliferation and morphometric analysis indicated an increase in fractional peroxisomal volume of X 8 and X 4 for clofibric acid (1 mM) and trichloroacetic acid (2.5 mM), respectively. SDS-PAGE of cell homogenates revealed an intensified protein band of mol. wt. 76-78,000. The induction of peroxisomal beta-oxidation by clofibric acid was elevated from 9- to 12-fold by supplementation of the medium with L-carnitine (2 mM).