Min Seon Ok, Kim Sung Hoon, Lee Sang Woo, Cho Jin A, Kim Kyung Sik
Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
Korean J Hepatol. 2011 Jun;17(2):139-47. doi: 10.3350/kjhep.2011.17.2.139.
BACKGROUND/AIMS: Ischemic preconditioning (IP) decreases severity of liver necrosis and has anti-apoptotic effects in previous studies using liver regeneration in normal rats. This study assessed the effect of IP on liver regeneration after hepatic resection in cirrhotic rats.
To induce liver cirrhosis, thioacetamide (300 mg/kg) was injected intraperitoneally into Sprague-Dawley rats twice per week for 16 weeks. Animals were divided into four groups: non-clamping (NC), total clamping (TC), IP, and intermittent clamping (IC). Ischemic injury was induced by clamping the left portal pedicle including the portal vein and hepatic artery. Liver enzymes alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured to assess liver damage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining for apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell replication were also performed.
Day-1 ALT and AST were highest in IP, however, levels in NC and IC were comparably low on days 1-7. There was no significant correlation of AST or ALT with experimental groups (P=0.615 and P=0.186). On TUNEL, numbers of apoptotic cells at 100× magnification (cells/field) were 31.8±24.2 in NC, 69.0±72.3 in TC, 80.2±63.1 in IP, and 21.2±20.8 in IC (P<0.05). When regeneration capacity was assessed by PCNA staining, PCNA-positive cells (cells/field) at 400× were 3.4±6.0 in NC, 16.9±69 in TC, 17.0±7.8 in IP and 7.4±7.6 in IC (P<0.05).
Although regeneration capacity in IP is higher than IC, the liver is vulnerable to ischemic damage in cirrhotic rats. Careful consideration is needed in applying IP in the clinical setting.
背景/目的：在以往使用正常大鼠肝脏再生的研究中，缺血预处理（IP）可减轻肝坏死的严重程度并具有抗凋亡作用。本研究评估了IP对肝硬化大鼠肝切除术后肝脏再生的影响。
为诱导肝硬化，将硫代乙酰胺（300mg/kg）每周两次腹腔注射到Sprague-Dawley大鼠体内，持续16周。动物被分为四组：非夹闭组（NC）、完全夹闭组（TC）、缺血预处理组（IP）和间歇性夹闭组（IC）。通过夹闭包括门静脉和肝动脉的左门静脉蒂诱导缺血性损伤。测量肝酶丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）以评估肝损伤。还进行了末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记（TUNEL）染色检测凋亡以及增殖细胞核抗原（PCNA）染色检测细胞增殖。
术后第1天IP组的ALT和AST最高，然而，NC组和IC组在术后1 - 7天的水平相对较低。AST或ALT与实验组之间无显著相关性（P = 0.615和P = 0.186）。在TUNEL检测中，100倍放大倍数下（细胞/视野）的凋亡细胞数在NC组为31.8±24.2，TC组为69.0±72.3，IP组为80.2±63.1，IC组为21.2±20.8（P<0.05）。当通过PCNA染色评估再生能力时，400倍放大倍数下PCNA阳性细胞（细胞/视野）在NC组为3.4±6.0，TC组为16.9±69，IP组为17.0±7.8，IC组为7.4±7.6（P<0.05）。
尽管IP组的再生能力高于IC组，但肝硬化大鼠的肝脏易受缺血损伤。在临床应用IP时需要仔细考虑。
