title: Mirex uptake and tissue disposition in intact and adrenalectomized rats.
abstract: The toxicity of mirex, an organochlorine insecticide, is increased significantly in adrenalectomized rats. To determine if this might be due to alterations in the tissue distribution of mirex, a disposition study was conducted in intact, adrenalectomized, and adrenalectomized corticosterone-supplemented rats. The peak plasma levels of [14C]mirex were shifted from 2 hr in intact and adrenalectomized corticosterone-supplemented rats to 4 hr in the adrenalectomized rats. The initial uptake and disposition of [14C]mirex in the brain of the intact, adrenalectomized, and adrenalectomized corticosterone-supplemented rats was essentially the same from 0.5 to 6 hr after dosing. By 48 hr after dosing, the [14C]mirex concentration in the brain of intact and adrenalectomized rats was significantly higher than that in adrenalectomized corticosterone-supplemented rats. Brain to plasma ratios reflected this difference. Corticosterone supplements to adrenalectomized rats decreased the absorption of [14C]mirex in the brain. The uptake of [14C]mirex during the initial 6 hr after dosing in all other tissues studied (liver, kidney, testes, and omental fat) was essentially the same for the three treatment groups. By 48 hr postdose, [14C]mirex concentration per liver was significantly higher in intact than in adrenalectomized and adrenalectomized corticosterone-supplemented rats. The difference in [14C]mirex disposition between the three treatment groups was not due to alterations in metabolism or elimination.
authors.affiliation: Department of Biological Sciences, Mississippi State, Mississippi 39762.
authors.forename: L D
authors.initials: LD
authors.lastname: Brown
authors.forename: J D
authors.initials: JD
authors.lastname: Yarbrough
mesh_terms: D000315:Adrenalectomy; D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism; D002250:Carbon Radioisotopes; D003345:Corticosterone / Q000494:pharmacology; D007306:Insecticides / Q000493:pharmacokinetics*; D008099:Liver / Q000378:metabolism; D008297:Male; D008917:Mirex / Q000493:pharmacokinetics*; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D007306:Insecticides; D003345:Corticosterone; D008917:Mirex