title: Pharmacokinetics of [125I]-recombinant human interleukin-11: 2. Placental transfer and excretion into milk after subcutaneous administration to rats.
abstract: Placental transfer and excretion into milk of [125I]-rhIL-11 (recombinant human interleukin-11) after subcutaneous administration in female rats were investigated. After administration of [125I]-rhIL-11 to rats on the 14th day of gestation, radioactivity in the kidney was the highest among excised tissues, being 3 times higher than that in the plasma at 1.5 h. Radioactivity in other tissues, including the mammary gland, ovary, uterus, placenta and amniotic fluid, was lower than that in the plasma. Although radioactivity in fetuses was detected 6 h after administration, the level was only 2% of the plasma concentration in dams, and the radioactivity was not found in fetal-derived TCA precipitates. These results indicate that rhIL-11 does not readily pass through the placenta into the fetus. After subcutaneous administration of [125I]-rhIL-11 to lactating rats 14 days after delivery, radioactivity in milk was 1.1-1.6 times that in the plasma of dams. Radioactivity in clotted milk in the stomachs of suckling infants was almost equal to that in the dam's milk; however, only a small amount of radioactivity was detected in infant kidneys.
authors.affiliation: Drug Metabolism Laboratories, Yamanouchi Pharmaceutical Co. Ltd, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Uchida
authors.forename: K
authors.initials: K
authors.lastname: Aoyama
authors.forename: K
authors.initials: K
authors.lastname: Mori
authors.forename: T
authors.initials: T
authors.lastname: Usui
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Takariki
authors.forename: N
authors.initials: N
authors.lastname: Asahara
authors.forename: M
authors.initials: M
authors.lastname: Hirose
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Tateishi
authors.forename: S
authors.initials: S
authors.lastname: Higuchi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D017370:Interleukin-11 / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007774:Lactation / Q000378:metabolism; D008431:Maternal-Fetal Exchange; D008657:Metabolic Clearance Rate; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D017370:Interleukin-11; D007457:Iodine Radioisotopes; D011994:Recombinant Proteins