title: Toxicokinetics of 14C-endosulfan in male Sprague-Dawley rats following oral administration of single or repeated doses.
abstract: Endosulfan (ES), an organochlorine (OC) insecticide that belongs to the cyclodiene group, is one of the most commonly used pesticides to control pests in vegetables, cotton, and fruits. The toxicokinetics of 14C-endosulfan following oral administration of a single dose of 5 mg/kg body weight was investigated in male Sprague-Dawley rats. Three rats were sacrificed 30 min, 1 h, 2 h, 4 h, and 8 h after dosing. 14C-endosulfan radioactivity was detected in all tissues at each time point. In a separate experiment urine and feces were collected for 96 h. The total radioactivity recovered in the excreta for 4 days was 106.8% +/- 26.2%, with fecal elimination the major route of elimination route (94.4% +/- 21.4%). The cumulative excretion in the urine for 4 days was 12.4% +/- 4.8%. Radioactivity 8 h after administration was highest in gastrointestinal (GI) tract tissue (20.28 +/- 16.35 mg ES eq./L) and lowest in muscle (0.18 +/- 0.06 mg ES eq./L). The toxicokinetic parameters obtained from 14C-endosulfan-derived radioactivity in blood were distribution half-life (T1/2 x) = 31 min and terminal elimination half-life (T1/2 y) = 193 h. Blood concentration reached its maximum (Cmax) of 0.36 +/- 0.08 mg ES eq./L 2 h after the oral dose. Endosulfan was rapidly absorbed into the GI tract in rats, with an absorption rate constant (ka) of 3.07 h(-1).
authors.affiliation: Department of Global Environment Engineering, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Kyoto 606-8501, Japan. melissa@risk.env.kyoto-u.ac.jp
authors.forename: Melissa P L
authors.initials: MP
authors.lastname: Chan
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Morisawa
authors.forename: Aki
authors.initials: A
authors.lastname: Nakayama
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kawamoto
authors.forename: Miki
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoneda
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002250:Carbon Radioisotopes; D004726:Endosulfan / Q000493:pharmacokinetics* / Q000633:toxicity; D005243:Feces / Q000737:chemistry; D041981:Gastrointestinal Tract / Q000378:metabolism; D006207:Half-Life; D007306:Insecticides / Q000493:pharmacokinetics* / Q000633:toxicity; D008297:Male; D008657:Metabolic Clearance Rate; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D002250:Carbon Radioisotopes; D007306:Insecticides; D004726:Endosulfan