Braulio V B, Kouyoumdjian M, Zucoloto S, Figueiredo F, Borges D R
Department of Medicine, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Brazil.
Liver. 1998 Dec;18(6):371-7. doi: 10.1111/j.1600-0676.1998.tb00820.x.
AIMS/BACKGROUND: The liver clears circulating plasma-kallikrein through a receptor-mediated endocytosis process: an initial fast phase is followed by a slow exponential phase.
To determine whether the clearance rate of plasma-kallikrein is affected during liver regeneration, we perfused isolated rat livers with rat plasma-kallikrein (rPK) at 0, 1, 2, 3 and 7 days after partial hepatectomy or sham operation.
Liver regeneration was followed by the expression of the proliferating-cell nuclear antigen (PCNA) labeling index. The serum concentration of alpha2-macroglobulin, an acute phase protein in rats, was measured. At day 1, the fast phase of rPK clearance rate increased in hepatectomized rats when compared with day 0 (4.9+/-0.4 and 3.7+/-0.4 mU/g liver min, p<0.05). However, at day 2, the rPK fast phase clearance rate dropped significantly (2.6+/-0.2, p<0.05), when compared with day 1. No difference was found among the sham groups at different days of hepatectomy. These changes seem to be independent of the acute phase reaction. The regenerative liver weight increased continuously during the observation period. PCNA expression increased significantly after hepatectomy, with maximal PCNA-labeling indices at days 1 and 2, declining thereafter.
The rPK fast phase clearance rate changes during liver regeneration, with a zenith occurring when PCNA labeling index is maximal (day 1) and a nadir occurring at the mitotic phase (day 2).
目的/背景：肝脏通过受体介导的内吞作用清除循环中的血浆激肽释放酶：最初为快速清除阶段，随后是缓慢的指数清除阶段。
为了确定肝脏再生过程中血浆激肽释放酶的清除率是否受到影响，我们在部分肝切除或假手术后的0、1、2、3和7天，用大鼠血浆激肽释放酶（rPK）灌注分离的大鼠肝脏。
通过增殖细胞核抗原（PCNA）标记指数来跟踪肝脏再生情况。测定了大鼠急性期蛋白α2-巨球蛋白的血清浓度。在第1天，与第0天相比，肝切除大鼠的rPK清除率快速清除阶段有所增加（分别为4.9±0.4和3.7±0.4 mU/g肝脏·分钟，p<0.05）。然而，与第1天相比，在第2天，rPK快速清除阶段的清除率显著下降（2.6±0.2，p<0.05）。在肝切除不同天数的假手术组之间未发现差异。这些变化似乎与急性期反应无关。在观察期内，再生肝脏重量持续增加。肝切除后PCNA表达显著增加，在第1天和第2天PCNA标记指数最高，此后下降。
肝脏再生过程中rPK快速清除阶段的清除率发生变化，在PCNA标记指数最高时（第1天）达到峰值，在有丝分裂期（第2天）达到谷底。
