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United States Department of Agriculture

Agricultural Research Service

Title: Hepatic Microsomal Desulfuration and Dearylation of Chlorpyrifos and Parathion in Fingerling Channel Catfish: Lack of Effect from Aroclor 1254

Authors
item Straus, David
item Schlenk, Daniel - MISSISSIPPI STATE UNIV
item Chambers,, Janice - UNIV OF MISSISSIPPI

Submitted to: Aquatic Toxicology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 20, 1999
Publication Date: August 1, 2000
Citation: STRAUS, D.L., SCHLENK, D., CHAMBERS,, J.E. HEPATIC MICROSOMAL DESULFURATION AND DEARYLATION OF CHLORPYRIFOS AND PARATHION IN FINGERLING CHANNEL CATFISH: LACK OF EFFECT FROM AROCLOR 1254. AQUATIC TOXICOLOGY. 2000. v.50. p.141-149.

Interpretive Summary: Channel catfish were injected with Aroclor 1254 a PCB mixture and sacrificed at 96 h to observe the effects of this inducer on metabolism of 2 organophosphate insecticides. The rate of activation and detoxification of these insecticides was determined in untreated fish. These experiments indicate that Aroclor 1254 did not induce the enzymes responsible for metabolism of the insecticides.

Technical Abstract: Channel catfish were treated intraperitoneally with 100 mg Aroclor 1254kg body wt and sacrificed at 96 h to observe the effects of this inducer on metabolism. In the initial experiment, hepatic microsomal deethylation of 7 ethoxyresorufin EROD OF THE Aroclor treated fish was higher, but not significantly; no effects on desulfuration or dearylation of chlorpyrifos or parathion were evident. In the second experiment, total hepatic microsomal cytochrome P450 P450s content was not induced by Aroclor; however, both specific P450s enzyme content as measured by Western blot analyses using polyclonal antibodies raised to rainbow trout hepatic P450s and EROD specific activity indicated significant induction of proteins recognized by the CYP1A1 antibody. No change in other P450s was evident i.e. CYP2K1, CYP2M1, and CYP3A27. These experiments indicate that Aroclor 1254 did not induce the P450s responsible for metabolism of the phosphorothionate insecticides.

Last Modified: 4/20/2014
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