title: Evaluation of the respiratory elimination kinetics of selenate and Se-methylselenocysteine after oral administration in lambs.
abstract: Sheep can be acutely poisoned by selenium (Se) accumulating forages which often contain selenate or Se-methylselenocysteine as their predominant forms. Excess Se can be eliminated via respiration. Sheep were given a single oral dose of 0, 1, 2, 3, 4, or 6 mg Se/kg BW as sodium selenate and Se-methylselenocysteine or 6 mg Se/kg BW as sodium selenite or selenomethionine. Expired air samples were collected and analyzed for Se. The Se concentration of the expired air reflected a dose-dependent increase at individual time points for both Se-methylselenocysteine and sodium selenate, however, Se content was greater and eliminated more rapidly from sheep receiving Se-methylselenocysteine. The mean Se concentration in respired air from sheep administered 6 mg Se/kg BW of different selenocompounds was greatest in sheep dosed Se-methylselenocysteine > selenomethionine > sodium selenate > sodium selenite. The Se concentration in respired air of acutely poisoned sheep is significantly different for different chemical forms of Se.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Poisonous Plant Research Laboratory, 1150 E. 1400 N., Logan, UT, USA. Electronic address: Zane.Davis@ars.usda.gov.
authors.forename: T Z
authors.initials: TZ
authors.lastname: Davis
authors.forename: B L
authors.initials: BL
authors.lastname: Stegelmeier
authors.forename: B T
authors.initials: BT
authors.lastname: Green
authors.forename: K D
authors.initials: KD
authors.lastname: Welch
authors.forename: J O
authors.initials: JO
authors.lastname: Hall
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001944:Breath Tests; D004305:Dose-Response Relationship, Drug; D045853:Exhalation; D064586:Selenic Acid / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D017279:Selenocysteine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000032:analysis / Q000493:pharmacokinetics; D012756:Sheep
chemical_list: D017279:Selenocysteine; D064586:Selenic Acid; C002979:selenomethylselenocysteine
keywords: Respiratory elimination; Se-methylselenocysteine; Selenate; Selenium