大鼠肝癌前病灶与卵圆细胞的关系

Relationship between oval cells and preneoplastic lesions induced by 2 acetylaminofluorine in rat liver

目的探讨肝脏癌前病灶的细胞学起源。方法用雄性Ｆｉｓｈｅｒ３４４大鼠，在两个不同的化学致癌模型中，用放射自显影方法追踪癌前病灶的发生与卵圆细胞（ｏｖａｌｃｅｌ）或肝细胞的关系。模型Ⅰ动物连续饲喂含００２％二乙酰胺基芴（２ＡＡＦ）共２８天，第７天作２／３肝大部切除（２／３ＰＨ）以刺激卵圆细胞增生，第１２天用３ＨＴｄｒ腹腔注射以选择性标记卵圆细胞；模型Ⅱ在２８天连续饲喂００２％２ＡＡＦ之前第９天，先进行２／３ＰＨ，术后２２小时用３ＨＴｄｒ腹腔注射以标记代偿性增生的肝细胞。结果模型Ⅰ与模型Ⅱ在癌前病灶出现之前分别获得了对卵圆细胞和肝细胞的选择性标记，而癌前病灶细胞核内的示踪银颗粒只出现在卵圆细胞被选择性标记的模型Ⅰ中。结论提供了大鼠以２ＡＡＦ为致癌物诱发的癌前病灶来自卵圆细胞的直接证据。

Objective To study the cellular origin of preneoplastic lesion of liver induced by the 2 acetylaminofluorine (2 AAF) in rat. Methods male fisher 344 rats were used for two different carcinogenesis models. Model 1: Rats were fed with regular diet containing 0.02% 2 AAF for totally 28 days, and subjected to a standard two thirds partial hepatectomy (2/3 PH) on the 7th day in order to stimulate the proliferation of oval cells. 3H thymidine ( 3H Tdr) was administered intraperitoneally on the 12th day for selective labelling of oval cells. Model Ⅱ: Rats were subjected to 2/3 PH and 3H Tdr was administered intraperitoneally 22 hours after the operation for the selective labelling of hepatocytes. The rats were then fed with 2 AAF for totally 28 days after a 9 days recovery period from 2/3 PH. The relationship between preneoplastic lesion and selectively labelled oval cells, or hepatocytes, was traced by autoradiography. Results Pathological examination and autoradiography denoted that the silver grains (labelled signals) were only formed in the preneoplastic cells in model I rather than the cells of model II animals. Conlusion It is a direct evidence to demonstrate that the preneoplastic cells are mostly originated from the oval cells.