ascorbic-acid and 2-4-dichlorophenol

Chlorinated phenols are widely used in the manufacture of biocides and wood preservatives. 2,4-dichlorophenol administered perorally 3 times a week at a dose of 40 mg in 0.2 ml of olive oil per kg of body weight to guinea pigs increased lipid peroxidation in liver and adrenals after 2 weeks of treatment. A high intake of ascorbic acid (50 mg/animal/day) significantly decreased lipid peroxidation in the liver of 2, 4-dichlorophenol treated guinea pigs in comparison to guinea pigs with low ascorbic acid intake (2 mg/animal/day). 2,4-dichlorophenol accumulation was also decreased in the liver of animals with high ascorbic acid intake. Increased daily intake of vitamin C to persons involved in production and use of chlorophenoxy herbicides is recommended.

Topics: Adrenal Glands; Analysis of Variance; Animals; Ascorbic Acid; Chlorophenols; Guinea Pigs; Lipid Peroxidation; Liver; Male; Regression Analysis

Chlorophenols, mainly used as biocides, are compounds with a wide spectrum of toxic effects including teratogenic and carcinogenic actions. In this study, the effects of 2,4-dichlorophenol (2,4-DCP) on hepatic microsomal cytochrome P-450, NADPH-cytochrome c reductase activity, liver ascorbic acid (AA) and glutathione (GSH) content were studied in guinea-pigs with a low (2 mg/day/animal) or a high (50 mg/day/animal) ascorbic acid intake. The high AA intake significantly increased liver AA and GSH levels. There was a clear-cut correlation between liver AA and GSH levels. Administration of 2,4-DCP significantly decreased cytochrome P-450 and NADPH-cytochrome c reductase activity in hepatic microsomes isolated from guinea-pigs with the low AA intake. Such a reduction was not observed in intoxicated guinea-pigs with the high AA intake. The results suggest that AA can play a protective role in 2,4-DCP toxicity.

Topics: Animals; Ascorbic Acid; Chlorophenols; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Glutathione; Guinea Pigs; Liver; Male; Microsomes, Liver

Peroxidase activity in the uterine luminal fluid of mice treated with diethylstilbestrol was measured by the guaiacol assay and also by the formation of 3H2O from [2-3H]estradiol. In the radiometric assay, the generation of 3H2O and 3H-labeled water-soluble products was dependent on H2O2 (25 to 100 microM), with higher concentrations being inhibitory. Tyrosine or 2,4-dichlorophenol strongly enhanced the reaction catalyzed either by the luminal fluid peroxidase or the enzyme in the CaCl2 extract of the uterus, but decreased the formation of 3H2O from [2-3H]estradiol by lactoperoxidase in the presence of H2O2 (80 microM). NADPH, ascorbate, and cytochrome c inhibited both luminal fluid and uterine tissue peroxidase activity to the same extent, while superoxide dismutase showed a marginal activating effect. Lactoferrin, a major protein component of uterine luminal fluid, was shown not to contribute to its peroxidative activity, and such an effect by prostaglandin synthase was also ruled out. However, it was not possible to exclude eosinophil peroxidase, brought to the uterus after estrogen stimulation, as being the source of peroxidase activity in uterine luminal fluid.

Topics: Animals; Ascorbic Acid; Body Fluids; Chlorophenols; Cytochrome c Group; Diethylstilbestrol; Estradiol; Female; Glutathione; Hydrogen Peroxide; Lactoperoxidase; Mice; NADP; Peroxidase; Superoxide Dismutase; Tritium; Tyrosine; Uterus; Water