大鼠肝抑素提取物对肝再生过程的影响

EFFECT OF RAT HEPATIC CHALONE EXTRACT ON LIVER REGENERATION

制备大鼠肝抑素，研究它对肝再生过程的影响。应用酒精沉析和超速离心法从正常大鼠肝提取肝抑素提取物（ＨＣ），将其注入肝大部切除大鼠体内。每１２ｈ一次至９６ｈ。每１２ｈ取残余肝测重量和体积，计肝细胞分裂指数（ＭＩ），用体视法测肝细胞数，用流式细胞术测分离肝细胞含不同ＤＮＡ倍体的细胞数。结果：①再生肝重量和体积增长缓慢，至９６ｈ为对照组的７１％；②肝细胞ＭＩ明显降低，ＭＩ高峰延后并为对照组的３３％；③再生肝肝细胞数增长缓慢，至９６ｈ为对照组的６９，８％；④４倍体肝细胞ＤＮＡ合成受阻，Ｓ期和８倍肝细胞数增长现象（见于对照组）消失。结论：ＨＣ提取物具有延缓肝再生的生物活性，它主要阻滞４ｎ肝细胞合成ＤＮＡ，抑制再生肝肝细胞的增殖与分裂。

PURPOSE The crude extract of rat hepatic chalone(HC)was prepared and its biological effect on rat liver regeneration was assayed in vivo.METHODS HC crude extract was prepared from normal rat livers by ethanol precipitation and ultracentrifugation and injected to subtotal hepatectomized rats per 12 h within 96 h, Interval 12 h respectively,the weight and volume of regeneration liver were measured and the mitotic index(MI) and number of hepatocytes in regenerating livers were counted with stereological method. DNA content of hepatocyte and numbers of hepatocytes containing different DNAfold in isolated hepatocytes were measured using flow-cytometry.RESULTS①The weight and volum of regenerating liver increased slowly and were 71% of that of control at 96 h after operation;②MI of hepatocytes was obviously lower and MI peak was delayed and only 33% of that of control;③The number of hepatocytes in regenerating livers increased slowly and was 69.8%of that of control at 96 h;④DNA synthesis of tetraploid hepatocytes was inhibited and the increase of numbers of S-phase and octoploid hepatocytes as appeared in control could not be seen in H C injected rats.CONCLUSIONS The crude extract containing HC possesses biological activity that can delay the liver regeneration. It chiefly blocks DNA synthesis of 4n hepatocytes and inhibits proliferation and mitosis of hepatocytes in regenerating liver.