Tohno Y, Tohno S, Minami T, Matsubara H, Yamagiwa H, Kawaki H, Okazaki Y, Utsumi M, Yamada M
Dept. of Anatomy, Nara Medical University, Japan.
Cell Mol Biol (Noisy-le-grand). 1996 Dec;42(8):1121-7.
To examine intranuclear localization of metallothionein (MT) induced by administration of 4-aminopyrazolo [3,4-d] pyrimidine (4-APP), the present study of MT was performed by immuno-electron microscopy. One day after oral administration of 4-APP, the mouse pancreas removed and frozen with dry ice was cut at about 1 mm thickness. Pancreatic slices were reacted with anti-MT antibody, fixed with formaldehyde and glutaraldehyde, and embedded in hydrophilic Lowicryl K4M resin. Ultrathin sections were reacted with the secondary antibody labelled with colloidal gold, and stained both with uranyl acetate and with lead citrate. It was found that the MT site was shown simultaneously in the chromatin and in the rough endoplasmic reticulum of mouse pancreatic exocrine cells one day after administration of 4-APP. The structure of MT-binding chromatin was composed of supranucleosomal fibers, but not of nucleosomal fibers.
为检测4-氨基吡唑并[3,4-d]嘧啶（4-APP）给药诱导的金属硫蛋白（MT）的核内定位，本研究通过免疫电子显微镜对MT进行了研究。口服4-APP一天后，取出小鼠胰腺并用干冰冷冻，切成约1毫米厚。胰腺切片与抗MT抗体反应，用甲醛和戊二醛固定，然后包埋在亲水性Lowicryl K4M树脂中。超薄切片与胶体金标记的二抗反应，并用醋酸铀和柠檬酸铅染色。结果发现，给药4-APP一天后，小鼠胰腺外分泌细胞的染色质和粗面内质网中同时显示出MT位点。MT结合染色质的结构由超核小体纤维组成，而不是核小体纤维。
