Oral and dermal application of 2,4-dichlorophenoxyacetic acid sodium and dimethylamine salts to male rats: Investigations on absorption and excretion as well as induction of hepatic mixed-function oxidase activities
Absorption and urinary excretion of 2,4-dichlorophenoxyacetic acid sodium (sodium 2,4-D) and 2,4-dichlorophenoxyacetic acid dimethylammonium (2,4-DMA) salts were examined after single oral and middorsal skin applications of the herbicides to male rats. Doses of 2.6 mg 2,4-D/kg body wt (sodium 2,4-D) and 1.9 mg 2,4-D/kg body wt (2,4-DMA) were applied. Quantitatively, with both salts, most of the orally administered herbicide (over 90%) was excreted in urine within 28 h. However, 2,4-D urinary peak concentrations were measured 4.5 and 20.5 h after dosing with 2,4-DMA and sodium 2,4-D, respectively. Additionally, the volume of urine in the oral study was significantly increased with both salts when compared with the controls or the dermal exposure. After topical application, 2,4-D absorption was much lower than in the oral study. Urinary excretion only reached about 10 and 15% of the applied dose for sodium 2,4-D and 2,4-DMA, respectively, by 5 days post-treatment. Further, we found some elevations in hepatic cytochrome P-450 activities. Ethylmorphine N-demethylase was only slightly induced by the herbicides while ethoxyresorufin O-deethylase activity was increased nearly 2-fold by sodium 2,4-D.
Key words2,4-D Spritz Hormit (sodium 2,4-D) Spritz Hormin (2,4-DMA) Rats Urinary excretion Cytochrome P-450
- sodium 2,4-D
2,4-dichlorophenoxyacetic acid sodium salt
2,4-dichlorophenoxyacetic acid dimethylammonium salt
2-(2,4-dichlorophenoxy) propionic acid
Unable to display preview. Download preview PDF.
- Chemie AG Wolfen/Bitterfeld (1990) Certificate of 2,4-D analysis Ciba-Geigy, Basel, 1980Google Scholar
- Feldmann RJ, Maibach HI (1974) Percutaneous penetration of some pesticides and herbicides in man. Toxicol Pharmacol 28: 126–132Google Scholar
- Hietanen E, Linnainmaa K, Vainio H (1983) Effects of phenoxyherbicides and glyphosate on the hepatic and intestinal biotransformation activities in the rat. Acta Pharmacol Toxicol 53: 103–112Google Scholar
- Khanna S, Fang SC (1966) Metabolism of14C-labeled 2,4- dichlorophenoxyacetic acid in rats. J Agric Food Chem 14: 500–503Google Scholar
- Knopp D, Glass S (1991) Biological monitoring of 2,4-dichlorophenoxyacetic acid exposed workers in agriculture and forestry. Int Arch Occup Environ Health (in press)Google Scholar
- Knopp D, Richter G, Skerswetat M, Hermenau H, Stottmeister E (1991) Assessment of 2,4-dichlorophenoxyacetic acid exposure in chemical industry through biological monitoring. Advances in Controlled Clinical Inhalation Studies, 3rd Inhalation Symposium, 9–11 October 1991, Hannover, FRGGoogle Scholar