title: The disposition and intestinal absorption of zinc in rats.
abstract: The variety of physiologic and biologic functions of zinc is expected to enable the development of zinc-related medicines. In this study, the distribution of endogenous zinc, the disposition after intravenous injection, and the intestinal absorption of zinc were investigated in vivo using rats from the viewpoints of pharmaceutical science and pharmacokinetics. High levels of endogenous zinc were observed in bone, testis, and liver. RT-PCR analysis on the mRNA of metallothionein in tissues clarified that it is significantly correlated with the distribution of zinc, suggesting that zinc is accumulated in tissues as a complex with MT. Following intravenous injection, uptake of zinc was high in liver, spleen, pancreas, kidney, and intestine. Fractional absorptions of zinc after oral administration to fasted rats were greater than those to fed rats, suggesting that some factors in diet inhibit the absorption of zinc. In fasted rats, fractional absorption was slightly decreased in high-dose group, suggesting the involvement of carrier-mediated transport. Study utilizing an in situ closed-loop method also indicated saturable intestinal absorption of zinc. These findings will further the research and development of zinc-related medicines by providing basic and important information on zinc.
authors: Department of Biopharmaceutics, Kyoto Pharmaceutical University, Misasaginakauchi-cho 5, Yamashina-ku, Kyoto 6078414, Japan. yasuno-tohru@linical.co.jp
authors: Tohru
authors: T
authors: Yasuno
authors: Hiroki
authors: H
authors: Okamoto
authors: Miho
authors: M
authors: Nagai
authors: Shunsuke
authors: S
authors: Kimura
authors: Takanori
authors: T
authors: Yamamoto
authors: Kozue
authors: K
authors: Nagano
authors: Tomoyuki
authors: T
authors: Furubayashi
authors: Yutaka
authors: Y
authors: Yoshikawa
authors: Hiroyuki
authors: H
authors: Yasui
authors: Hidemasa
authors: H
authors: Katsumi
authors: Toshiyasu
authors: T
authors: Sakane
authors: Akira
authors: A
authors: Yamamoto
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D008297:Male; D008668:Metallothionein / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution; D015032:Zinc / Q000097:blood / Q000378:metabolism*; D015033:Zinc Isotopes; D019287:Zinc Sulfate / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D015033:Zinc Isotopes; D019287:Zinc Sulfate; D008668:Metallothionein; D015032:Zinc