US EPA

1812972 

Journal Article 

The Effects Of Carbon Tetrachloride And Some Antioxidants On The Hydroxylation Of Tetralin By Rat Liver Homogenate 

Lin C-C; Chen, C 

1969 

1 

Biochimica et Biophysica Acta
ISSN: 0006-3002
EISSN: 1878-2434 

NIOSH/00160596 

192 

1 

133-135 

The effects of carbon-tetrachloride (56235) and antioxidants on tetralin (119642) hydroxylation was studied in rat liver homogenates. Fresh perfused rat liver homogenate supernatant fractions were used as the enzyme source. The medium contained the liver enzyme, NADP, glucose-6-phosphate, glucose-6-phosphate-dehydrogenase, and tetralin. Carbon-tetrachloride was added at different concentrations. In some tests, carbon-tetrachloride was preincubated with the enzyme preparation for 0, 5, 10, or 20 minutes prior to tetralin addition. In other tests, the following antioxidants were added at 1 millimolar alone or with carbon-tetrachloride at 1.27 milligrams per kilogram (mg/kg): N,N'-diphenyl-p-phenylenediamine (27137311), sodium-selenite (10102188), and alpha-tocopherol-acetate (58957). The enzymatic conversion of tetralin to tetralol (530916) was determined by gas liquid chromatography. At low concentrations, carbon-tetrachloride stimulated conversion of tetralin to tetralol; maximal hydroxylation, 200 to 300 percent, occurred at 1.4mg/kg. As the carbon-tetrachloride preincubation time increased, hydroxylation activity decreased. All three antioxidants tested alone inhibited enzymatic hydroxylation by at least 60 percent. alpha-Tocopherol-acetate and sodium-selenite reduced the carbon-tetrachloride stimulation by 50 percent, while N,N'-diphenyl-p-phenylenediamine completely eliminated it. The authors conclude that tetralin-hydroperoxide (771299) may be an intermediate in the hydroxylation of tetralin to tetralol in rat liver. 

DCN-148925; Toxic materials; Hepatotoxicity; Liver damage; Toxic effects; Liver; Toxic dose; Liver cells; Biological effects; Physiological function; Physiological testing; Physiology