Mullins J E, Fuentealba I C
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada.
Histol Histopathol. 1998 Jul;13(3):627-33. doi: 10.14670/HH-13.627.
Metallothionein (MT) has been used in immunohistochemical techniques to indicate presence and distribution of heavy metals within biological tissues. This study describes a comparison of the pattern of MT-immunostaining in the liver, duodenum and kidney during dietary copper overload in rats. Sixteen male 10-week-old Wistar rats were randomly allocated into groups of four. Two groups were fed a pelleted diet containing 1,500 mg/kg copper and two control groups received a rodent diet containing 10 mg/kg copper. After 6 weeks samples of liver, kidney and duodenum were collected for immunohistochemistry and histology. An indirect immunoperoxidase technique, using monoclonal antibody E9 against horse MT and polyclonal sera against rabbit MT, was employed. Copper-loaded rats had marked MT-immunoreactivity within the nucleus and cytoplasm of many periportal hepatocytes, renal proximal convoluted tubule epithelial cells, intestinal columnar epithelial cells and Paneth cells. Immunohistochemical staining was similar using either mouse anti-MT polyclonal serum, or monoclonal antibody E9. Hepatocytes surrounding inflammatory foci were positive for MT, supporting the proposed role of this protein in free radical scavenging. The presence of MT in the kidney appears to be associated with renal excretion of copper-metallothionein (Cu-MT) in copper-loaded rats. Paneth cells were easily detected using MT-immunostaining. MT may play a part in absorption of copper from intestinal contents and possible storage as Cu-MT in Paneth cells. The function of Paneth cells remains unknown but the presence of marked MT-immunoreactivity in these cells, observed in copper-loaded rats, suggests their involvement in homeostasis and metabolism of copper.
金属硫蛋白（MT）已被用于免疫组织化学技术，以指示生物组织中重金属的存在和分布。本研究描述了大鼠饮食铜过载期间肝脏、十二指肠和肾脏中MT免疫染色模式的比较。16只10周龄雄性Wistar大鼠随机分为四组，每组四只。两组喂食含1500 mg/kg铜的颗粒饲料，两组对照组喂食含10 mg/kg铜的啮齿动物饲料。6周后，采集肝脏、肾脏和十二指肠样本进行免疫组织化学和组织学检查。采用间接免疫过氧化物酶技术，使用抗马MT的单克隆抗体E9和抗兔MT的多克隆血清。铜负荷大鼠的许多门静脉周围肝细胞、肾近端曲管上皮细胞、肠柱状上皮细胞和潘氏细胞的细胞核和细胞质内有明显的MT免疫反应性。使用小鼠抗MT多克隆血清或单克隆抗体E9进行免疫组织化学染色相似。炎症灶周围的肝细胞MT呈阳性，支持了该蛋白在清除自由基中的作用。在铜负荷大鼠中，肾脏中MT的存在似乎与铜-金属硫蛋白（Cu-MT）的肾脏排泄有关。使用MT免疫染色很容易检测到潘氏细胞。MT可能参与从肠内容物中吸收铜，并可能以Cu-MT的形式储存在潘氏细胞中。潘氏细胞的功能尚不清楚，但在铜负荷大鼠中观察到这些细胞中有明显的MT免疫反应性，表明它们参与铜的稳态和代谢。
