多药耐药基因产物P-糖蛋白在正常人体组织中的分布和细胞定位

TISSUE DISTRIBUTION AND INTRA CELLULAR LOCALIZATION OF THE MULTIDRUG RESISTANCE GENE PRODUCT P-GLYCOPROTEIN IN NORMAL HUMAN TISSUES

采用两种抗P—糖蛋白抗体免疫组化检测了32份正常人体组织中多药耐药基因产物P—糖蛋白(P－gp)。结果发现，肾上腺、肾、肝、大肠、小肠、胰腺及甲状腺中P－gp高度表达。在肾上腺和甲状腺中，P－gp弥散分布于细胞浆质。在肾脏中，P—gp在近曲小管上皮细胞的管腔侧分布较多。在肝脏中，P—gp在肝细胞的胆管面和小胆管上皮细胞的管腔侧分布较多。在大肠中，P－gp表达水平有愈向远瑞愈高的趋势，阳性颗粒主要位于粘膜技状上皮细胞的管腔面。在小肠上皮细胞和胰腺小胰管上皮细胞P—gp分布也有朝向管腔侧较多的极性特点。P—gp在正常人体组织中的高度表达与其生理功能有关。

PURPOSE To study the expression of P-gp in normal human tissues.METHODS Tissue distribution and intracellular localization of the multidrug resistance gene product P-glycoprotein (P-gp) were detected by immunohistechemistry method using McAb JSB-1 and PcAb mdr(Ab-1 ) in normal human tissues.RESULTS P-gp was expressed strongly in the cytoplasm of the adrenal gland including cortex and medulla, kidney, liver, large intestine, small intestine, pancreas and thyroid. P-gp was distributed diffusely in the cytoplasm of the adrenal cells, but concentrated in the apical side of epithelial cells of the proximal tubules of the kidney. P-gp was also found in the biliary canalicular front of hepatocytes and the apical side of epithelial cells in small biliary ductules of the liver. High level of P-gp in the apical side of superficial columnar epithelial cells was found in the large intestine. In the pancreas and small intestine, P-gp was also found in the apical side of epithelial cells. In thyroid, P-gp was distributed homogeneously in cytoplasm.CONCLUSIONS P-gp has a role in physiological metabolism of normal human tissues.