阿米洛利可降低肝硬化大鼠的门静脉高压。

Amiloride reduces portal hypertension in rat liver cirrhosis.

机构信息

Department of Medicine II (Gastroenterology and Hepatology), Liver Center Munich, University of Munich e Grosshadern, Munich 81377, Germany.

出版信息

Gut. 2010 Jun;59(6):827-36. doi: 10.1136/gut.2009.197756.

DOI:10.1136/gut.2009.197756

PMID:20551467

Abstract

OBJECTIVE

This study aimed to investigate the effect of amiloride on portal hypertension. Amiloride is known to inhibit Na(+)/H(+) exchangers on activated hepatic stellate cells.

METHODS

Liver cirrhosis in rats was induced by bile duct ligation (BDL) or thioacetamide (TAA) administration. The effects of zymosan for Kupffer cell (KC) activation or a thromboxane (TX) analogue (U46619) were tested in isolated perfused livers of cirrhotic rats and in vivo. Downstream mechanisms were investigated using Rho kinase inhibitor (Y-27632) or amiloride. Acute and chronic effects of amiloride and canrenoate on portal pressure were compared in perfused livers and in vivo. TXB(2) efflux was measured by ELISA. The phosphorylation state of moesin (p-moesin) as an indicator of Rho kinase activity and expression of the thromboxane synthase were assessed by western blot analyses. The activity of hepatic stellate cells was analysed by western blot and staining for alpha-smooth muscle actin (alpha-SMA).

RESULTS

In BDL rats, KC activation via zymosan increased portal pressure. This was attenuated by the Rho kinase inhibitor Y-27632. Increased thromboxane efflux following zymosan infusion remained unaltered by Y-27632. The infusion of amiloride attenuated zymosan- and U46619-induced increases in portal perfusion pressure. In vivo, direct administration of amiloride, but not of canrenoate, lowered portal pressure. In TAA and BDL rats, treatment with amiloride for 3 days reduced basal portal pressure and KC-induced increases in portal pressure whereas canrenoate had no effect. In livers of amiloride-treated animals, the phosphorylation state of moesin and the number of alpha-SMA positive cells were reduced.

CONCLUSIONS

Amiloride lowers portal pressure in rat liver cirrhosis by inhibition of intrahepatic vasocontraction. Therefore, patients with cirrhosis and portal hypertension may benefit from amiloride therapy.

摘要

目的

本研究旨在探讨阿米洛利对门脉高压的影响。已知阿米洛利可抑制活化的肝星状细胞上的 Na(+)/H(+)交换器。

方法

通过胆管结扎（BDL）或硫代乙酰胺（TAA）给药诱导大鼠肝硬化。在肝硬化大鼠离体灌注肝脏和体内检测了酵母聚糖激活库普弗细胞（KC）或血栓烷（TX）类似物（U46619）的作用。使用 Rho 激酶抑制剂（Y-27632）或阿米洛利研究下游机制。在灌注肝脏和体内比较了阿米洛利和坎利酮对门脉压的急性和慢性影响。通过 ELISA 测量 TXB(2)外排。通过 Western blot 分析评估 moesin 的磷酸化状态（p-moesin）作为 Rho 激酶活性的指标和血栓烷合酶的表达。通过 Western blot 和α-平滑肌肌动蛋白（α-SMA）染色分析肝星状细胞的活性。

结果

在 BDL 大鼠中，酵母聚糖激活 KC 增加门脉压。这可被 Rho 激酶抑制剂 Y-27632 减弱。酵母聚糖输注后 TX 外排增加仍不受 Y-27632 影响。阿米洛利输注可减弱酵母聚糖和 U46619 诱导的门静脉灌注压升高。在体内，直接给予阿米洛利而非坎利酮可降低门脉压。在 TAA 和 BDL 大鼠中，阿米洛利治疗 3 天可降低基础门脉压和 KC 诱导的门脉压升高，而坎利酮则无作用。在阿米洛利治疗动物的肝脏中，moesin 的磷酸化状态和α-SMA 阳性细胞的数量减少。