ALTERNATIVE REGULATION BETWEEN THE Ya AND Yc SUBUNIT OF LIVER GLUTATHIONE S-TRANSFERASES IN HEPATITIS AND CANCEROUS RATS

大鼠自发性肝炎在某些方面与人类急性肝炎和肝癌相似。大鼠肝炎发生于约4月龄，大多数重度黄疸大鼠在一周内死亡。据了解，肝炎被确定为孟德尔式的隐性突变。我们推测，大鼠肝炎的机制可能是由于肝脏中酶的改变或缺乏。最近我们证实了那些繁殖超过一年的老鼠有肝脏肿瘤。众所周知，谷胱甘肽S-转移酶是肝脏中的主要代谢酶，也是肝癌的良好标志物。为探讨肝炎及肝癌发生的机制，本研究采用β-己基谷胱甘肽连接琼脂糖柱，聚焦层析，从肝炎大鼠和正常大鼠中分离纯化谷胱甘肽S-转移酶。七个主要的谷胱甘肽s-转移酶分离。我们发现谷胱甘肽S-转移酶1-1显著降低，而谷胱甘肽S-转移酶2-2则显著升高。据了解，基因是非常相似的，但不同的基因。因此，似乎在肝炎大鼠肝脏中基因表达发生了改变。我们制备了抗谷胱甘肽S-转移酶2-2和抗谷胱甘肽S-转移酶4-4的单克隆抗体。我们用免疫组织化学方法用抗体在有肿瘤结节的肝切片上确定酶的定位。谷胱甘肽S-转移酶2-2和4-4的表达似乎在肿瘤结节外，与正常大鼠相比，肝炎大鼠的基因表达明显改变。目前尚不清楚这种改变是由于临床现象还是遗传因素。基因分析正在进行中。

Spontaneously hepatitis in rats are similar in certain respects to human acute hepatitis and liver cancer. The hepatitis in rats occur at the age of approximately 4 months old and most rats with severe jaundice were died within one week. It was known that the hepatitis was identified as a recessive mutation of mendelian fashion. We have postulated that the mechanism of the hepatitis in rat may be due to enzyme alterations or lack in the liver. Recently. we confirmed that the rats which were breeding for over one year had liver tumors. It is well known that glutathione S-transferases are major metabolic enzyme in liver and very good marker of hepatoma.-Namely, expression of this enzyme reflects circumstances of liver.In order to investigate the mechanism of hepatitis and then hepatoma, glutathione S-transferases were purified from hepatitis rats and normal rats by -s-hexylglutathione-linked agarose column, chromatofocusing. Seven major glutathione s-transferases were isolated. We found that glutathione S-transferase 1-1 was markedly decrease, and conversely glutathione S-transferase 2-2 was markedly increase. It is known that the genes are very similar but different genes. So it seems that the gene expression alters in hepatitis rat liver. Glutathione S-transferase 4-4 also increased.We have produced a monoclonal antibody specific for glutathione S-transferase 2-2 and rabbit anti glutathione S-transferase 4-4. We determined the enzyme localization on the liver section which had neoplastic nodules by immunohistochemical method using the antibodies. The expression of glutathione S-transferase 2-2 and 4-4 seemed to be out of the neoplastic nodules.It is obvious that the gene expression alters in hepatitis rats as compared with in normal rats. It is not clear whether such a alteration is due to a clinical phenomenon, or genetical factor. Genetic analysis is now in progress.