Immunohistochemical study of enzymes using monoclonal antibodies: Oncofetal enzymes.

r-GTP和GST-被称为癌胎抗原。由于这些酶的单克隆抗体对癌症的诊断和癌变过程的阐明是有用的，我们制备了针对大鼠、兔和人肾脏r-GTP和人胎盘GST的单克隆抗体，并利用免疫组织化学检测了这些酶的定位。在成年大鼠肾脏中，r-GTP沿近端小管的刷状边缘、近端小管S_2和S_3节段的基底外膜和henle’s袢下降细肢的顶端细胞膜存在。在人和家兔肾脏中，r-GTP的分布规律与大鼠肾脏基本一致。妊娠18 d大鼠肾近端小管可识别r-GTP。免疫染色的强度随着动物的发育而增加。定位模式与成人基本相同。在大鼠肝脏中，新生儿（出生0-1天）和部分肝切除的大鼠沿胆管小叶间细胞尖膜和胆管小叶间细胞尖膜有强烈的反应，而在成年大鼠中，反应非常微弱。在人肝脏中，从妊娠7周到成年，沿胆管可见免疫反应，在产前阶段反应最强。提示r-GTP是肝细胞增殖的标志物，即肝内癌胎酶。而在肾脏和胰腺中则未见此变化。在足月人胎盘中，GST-定位于胚胎起源的合胞滋养细胞和x细胞的无定形细胞质中。本研究获得的单克隆抗体可为恶性组织中酶的肿瘤学研究提供良好的工具。

r-GTP and GST- are known as oncofetal antigens. Since monoclonal antibodies to these enzymes are useful in diagnosis of the cancer and in the elucidation of the cartinogenic process, we have prepared monoclonal antibodies to rat, rabbit and human r-GTP of kindney, and human placenta GST- and examined the localization of these enzymes using immunohistochemistry.In adult rat kidney, r-GTP was present along the brush borders of the proximal tubules, along the basolateral membranes of the S_2 and S_3 segments of the proximal tubules and the apical cell membranes of the descending thin limbs of henle's loop. In human and rabbit kidneies, the distribution patterns of r-GTP almost coincided with those of rat. r-GTP was recognized in proximal tubules at 18-days of gestation in rat kidney. The intensity of the immunostaining increased with the develpoment of animals. The localization pattern was almost the same as that of adult. In rat liver, strong reaction was recognized along the blie canaliculi and apical membrane of interlobular bile ductal cells in neonate(0-1 days of birbh) and in partial hepatectomized rat, however, very faint reaction was present in adult rat. In human liver, immunoreaction was seen along the bile canaliculi from 7-weeks of gestation to adult: the strongest reaction was recognized at the prenatal stages. These results suggested that r-GTP is a marker for proliferating liver cells, i.e. oncofetal enzyme in liver. However, it did not show such change of distribution pattern in kidney and pancreas.GST- was localized in the amorphous cytoplasm of syncytiotrophblasts and X-cells both of which are fetal origin, in full-term human placenta.The monoclonal antibodies in this study may provide a good tool for oncological research of the enzymes in maligant tissues.