PLATELET ACCUMULATION IN THE REMNANT LIVER AFTER PARTIAL HEPATECTOMY : THE ROLE OF PLATELETS IN LIVER REGENERATION

背景和目的。我们评估了部分肝切除术后肝脏中血小板积累的水平，并检查了血小板在肝脏再生中的作用。材料与方法。我们对小鼠进行了70%的部分肝切除术。小鼠按治疗方法分为三组；Hx组对照组注射生理盐水，Kd组用脂质体包埋二氯亚甲基二膦酸盐使库普弗细胞消失，Tp组给予抗血小板抗体，导致严重的血小板减少。通过组织化学检查和测定肝脏血小板中5-羟色胺含量来评估血小板易位。采用PCNA标记指数和肝/体重比检测肝再生。抗血小板组织化学染色显示，肝部分切除后，Hx组肝脏中有大量血小板聚集，而Kd和Tp组没有。Kd组和Tp组肝脏5-羟色胺无明显变化。肝切除术后36小时，血小板不参与肝脏的Kd组和Tp组PCNA标记指数分别为18.9【负正】8.1和28.1【负正】7.1%，明显低于Hx组（42.0【负正】7.6）。与Hx组相比，Kd组和Tp组肝切除术后肝/体重比恢复迟缓。本研究提示，kupffer细胞诱导肝切除术后血小板向肝脏转运，血小板的积累在肝再生中起重要作用。

Background and Aim. We evaluate the level of platelets accumulation in liver after partial hepatectomy and examined the role of platelets in liver regeneration.Materials and Methods. We performed 70% partial hepatectomy in mice. The mice divided into three groups by treatment ; Hx group was control injected with saline, Kd group was depleted kupffer cells by administration of liposome encapsulating dichloromethylene bisphosphonate, Tp group was given anti-platelet antibody with resulting severe thrombocytepenia. Translocation of platelets was assessed by histochemical findings and measuring 5-hydroxytryptamine contained in platelets which were existed in liver. Liver regeneration was examined by PCNA labeling index and liver/body weight ratio.Results. Anti-platelet histochemical staining revealed accumulation of many platelets in the liver of Hx group after partial hepatectomy, but not in Kd and Tp groups. Hepatic 5-hydroxytryptamine of Kd and Tp groups did not changed. At the time of 36hr after hepatectomy, PCNA labeling indexes of Kd and Tp groups, in which platelets did not participate in the liver, were 18.9【minus-plus】8.1 and 28.1【minus-plus】7.1% respectively, and those were markedly lower than that of Hx group (42.0【minus-plus】7.6). Restoration of liver/body weight ratio after hepatectomy were retarded in Kd and Tp groups compared to Hx group.Conclusion. This study suggests that kupffer cells induce the translocation of platelets to the liver after hepatectomy and that accumulating platelets play an important role in liver regeneration.