Abstract :
Various chemicals such as phthalate esters, hypolipidemic drugs, solvents like trichloroethylene, and certain herbicides have been identified as peroxisome proliferating agents (PPAs). In many vertebrates, species- and even gender-specific sensitivities to peroxisome proliferation (PP) and toxicity, have been described and may correlate with inducibility of lauric acid hydroxylase activity. Little is known about PP in fish. The rainbow trout does not appear to be inducible for lauric acid hydroxylases (LMC1 and LMC2; CYP2M1 and CYP2K1, respectively) in response to the hypolipidemic drug, clofibrate. Fish other than trout, such as bluegill and catfish, are more acutely sensitive to phthalate ester toxicity. In this study, bluegill and catfish were examined for inducibility of anti-trout LMC1 and LMC2 immunoreactive proteins, 48 h after intra-pentoneal (i.p.) administration of olive oil vehicle, 200 mg/kg clofibrate, or 100 mg/kg ciprofibrate. In control animals, immunoreactive proteins were recognized in a sex-specific manner in both bluegill and catfish liver, and in catfish kidney. In treated animals, male immunoreactive proteins were induced to a greater extent than female, and ciprofibrate was the more potent inducer. The response of bluegill and catfish, therefore, is similar to the response of PPA-sensitive species.
