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

背景和目标。我们评估了部分肝切除术后血小板在肝脏中的积聚水平，并研究了血小板在肝再生中的作用。我们在小鼠中进行了70%的部分肝切除术。将小鼠随机分为3组，Hx组为生理盐水对照组，Kd组为脂质体介导的去枯否细胞组，Tp组为抗血小板抗体诱导的严重血小板减少组。通过组织化学和5-羟色胺含量的测定来评价肝内血小板的移位。以PCNA标记指数和肝/体重比值检测肝再生情况。抗血小板组织化学染色显示部分肝切除后Hx组肝内有大量血小板聚集，而Kd组和Tp组肝内无血小板聚集。Kd组和Tp组肝脏5-HT含量无明显变化。术后36小时，血小板不参与肝组织的Kd组和Tp组的PCNA标记指数分别为18.9 ± 8.1和28.1 ± 7.1%，均明显低于Hx组（42.0 ± 7.6）。肝切除术后肝/体重比的恢复在Kd组和Tp组较Hx组延迟。这项研究表明，枯否细胞诱导血小板移位到肝切除术后的肝脏和血小板的积累在肝再生中发挥重要作用。

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.