The fate of 14C-carbendazim in rat.

Abstract

The disappearance of 14C-carbendazim in rat (i.v. 12 mg/kg) followed the kinetics of a two-compartment open-system model. Half-lives of the alpha-phase were 0.1 h (blood), 0.16 h (liver), 0.25 h (kidney), and of the beta-phase: 2.15 h, 6.15 h, respectively. Two metabolites: methyl 5-hydroxy-2-benzimidazolecarbamate (5-HBC) and 2-aminobenzimidazole (2-AB) were formed very rapidly. Their peak concentrations in liver and kidney were 15 min after i.v. injection. Unchanged carbendazim was found in highest concentrations in blood. 5-HBC prevails in organs. 2-AB was present only in minor amounts. The extent of bioavailability in orally administered 14C-carbendazim (12 mg/kg) was about 85%. The disposition of radioactivity in subcellular fractions was not uniform, its highest concentration was in cytosol, the lowest in microsomes. The elimination of 14C-carbendazim in urine is biphasic. Half-lives of the alpha-phase were 1.4 h (i.v.) and 2.5 h (oral), and of the beta-phase 11.2 h and 12.1 h, respectively. Irrespective of the route of administration, 95% of the radioactivity in urine was composed of 5-HBC. The concentration of unchanged carbendazim in blood and of 5-HBC in urine may be of diagnostic value in acute poisoning with carbendazim.

• Authors: J Krechniak, B Kłosowska
• Journal: Xenobiotica; the fate of foreign compounds in biological systems (Xenobiotica) Vol. 16 Issue 9 Pg. 809-15 (Sep 1986) ISSN: 0049-8254 [Print] England
• PMID: 3765661 (Publication Type: Journal Article)

Chemical References

• Benzimidazoles
• Carbamates
• carbendazim

Topics

• Administration, Oral
• Animals
• Benzimidazoles (metabolism)
• Biotransformation
• Body Fluids (metabolism)
• Carbamates
• Injections, Intravenous
• Intestinal Absorption
• Male
• Microsomes, Liver (metabolism)
• Rats
• Time Factors
• Tissue Distribution