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Hepatic microvascular pressure during circulatory shock

循环休克期间的肝微血管压力

基本信息

批准号：
18591730
负责人：
SHIBAMOTO Toshishige
金额：
$ 2.31万
依托单位：
Kanazawa Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

The main purpose of this study is to measure the hepatic microvascular pressure during circulatory shock in anesthetized rats. The transmural pressure (Pμhv) of the hepatic venule (the diameter 30-50μm) at the liver surface was measured, using a servonull micropipette pressure-measuring system. At first, we compared Pphv with the hepatic occlusion pressures determined with the hepatic vascular occlusion methods developed by the authors (Am. J. Physiol. 286:H121-H130, 2004) in isolated perfused rat livers during the basal states and hepatic venoconstriction induced by norepinephrine, increased blood flow and hepatic anaphylaxis. We found that Pphv is close to the double ooclusion pressure rather than the hepatic venous occlusion pressure. The second, we measured Pphv during anaphylactic hypotension in anesthetized rats. Anaphylactic hypotension was induced by an intravenous injection of 0.6 mg ovalbumin. When the antigen was injected, the systemic arterial pressure decreased profoundly … More to approximately 45 mmHg, which was accompanied by an increase in Ppv and Pphv: Pphv only transiently increased by 5.7 cmH_2O at lmin and then rapidly returned to the baseline within 2 min, when Ppv continued to increase and reached the peak of 36 cm H_2O at 3.5 min. This indicated that the constriction of the portal veins and the sinusoids much predominate over that of the hepatic veins. Along with this hepatic pre and sinusoidal constriction, the liver lobe thickness significantly decreased by 4% after antigen. Presinusoidal constriction during anaphylactic shock in anesthetized rats increased the portal venous pressure while the hepatic venular pressure only increased slightly and transiently. This predominant presinusoidal constriction is accompanied by a passive decrease in liver volume. Finally, we measured Pphv during endotoxin shock in anesthetized rats. Similar to anaphylactic hypotension, only transient and small increase in Pμhv was observed in response to an intravenous injection of E. coli endotoxin (10〜30mg/kg), indicating that the presinusoidal constriction was predominant during endotoxin shock in anesthetized rats. Less

本研究的主要目的是测定麻醉大鼠循环休克时肝脏微血管压力。用微吸管测压系统测定肝表面肝微静脉（直径30-50μm）的跨壁压（Pμhv）。首先，我们将Pphv与作者开发的肝血管闭塞方法确定的肝闭塞压力进行了比较（Am. J.Physiol.286：H121-H130，2004）在基础状态和由去甲肾上腺素诱导的肝静脉收缩、血流量增加和肝过敏反应期间在分离的灌注大鼠肝脏中的作用。发现Pphv接近于双闭塞压而不是肝静脉闭塞压。第二，我们在麻醉大鼠过敏性低血压过程中测定了Pphv。通过静脉注射0.6 mg卵清蛋白诱导过敏性低血压。注射抗原后，体循环动脉压显著下降 ...更多信息 Ppv和Pphv在1 min时仅短暂增加5.7cmH_2O，2 min内迅速恢复到基线水平，Ppv继续增加，3.5min时达峰值36cmH_2O，表明门静脉和肝窦的收缩作用明显优于肝静脉。沿着这种肝前和肝窦收缩，肝叶厚度在抗原后显著降低4%。过敏性休克时窦前收缩可使门静脉压升高，而肝小静脉压仅短暂轻微升高。这种主要的窦前收缩伴随着肝脏体积的被动减少。最后，我们在麻醉大鼠内毒素休克期间测量Pphv。与过敏性低血压相似，静脉注射E后，仅观察到Pμhv一过性小幅升高。coli内毒素（10 ~ 30 mg/kg）对豚鼠耳蜗窦前区的收缩作用明显增强，提示内毒素休克时窦前区的收缩作用占优势。少