Tsukamoto H, Xi X P
Hepatopancreatic Research Laboratory, Veterans Administration Medical Center, Martinez, California 94553.
Hepatology. 1989 Feb;9(2):302-6. doi: 10.1002/hep.1840090223.
Centrilobular hypoxia mediated by enhanced hepatic consumption of oxygen has been hypothesized to be a factor of pathogenetic importance in ethanol-induced liver injury. In the present study, this hypothesis was tested in a rat model which developed alcoholic centrilobular liver necrosis. Male Wistar rats were infused with high fat diet plus ethanol or isocaloric glucose for 7 weeks, a duration which resulted in induction of balloon cell degeneration, focal necrosis, and inflammation in the centrilobular region of the liver of the ethanol-fed animals. Hepatic blood flow, oxygen consumption and oxygen delivery were determined by the radiolabeled microsphere method and measurement of oxygen content in arterial, portal venous, and hepatic venous blood. Hepatic oxygen consumption was markedly increased by 159% in the ethanol-fed animals compared to that in the controls when results were expressed as relative to body weight. Even after these results were standardized per gram of liver weight, hepatic oxygen consumption was still significantly elevated in the ethanol-fed group, but the magnitude of the elevation was reduced to 70%, due to marked hepatomegaly observed in these animals. There was a concomitant 59% increase in hepatic oxygen delivery in the ethanol-fed rats when expressed per kilogram of body weight, and this effect was attributable entirely to increased portal blood flow. However, the increment of this increase in oxygen delivery was much too small to compensate for the 159% increase in oxygen consumption. In addition, this increase in hepatic oxygen delivery was no longer observable when the results were reexpressed based on the liver weight.(ABSTRACT TRUNCATED AT 250 WORDS)
肝脏对氧气消耗增加所介导的小叶中心性缺氧被认为是乙醇性肝损伤发病机制中的一个重要因素。在本研究中,该假设在一个发生酒精性小叶中心性肝坏死的大鼠模型中进行了验证。雄性Wistar大鼠接受高脂肪饮食加乙醇或等热量葡萄糖输注7周,这一时间段导致喂食乙醇的动物肝脏小叶中心区域出现气球样细胞变性、局灶性坏死和炎症。通过放射性微球法以及测定动脉血、门静脉血和肝静脉血中的氧含量来确定肝血流量、氧消耗和氧输送。当以相对于体重来表示结果时,喂食乙醇的动物肝脏氧消耗比对照组显著增加了159%。即使将这些结果按每克肝脏重量进行标准化后,喂食乙醇组的肝脏氧消耗仍显著升高,但由于在这些动物中观察到明显的肝肿大,升高幅度降至70%。当按每千克体重表示时,喂食乙醇的大鼠肝脏氧输送伴随增加了59%,且这种效应完全归因于门静脉血流量的增加。然而,这种氧输送增加的幅度太小,无法补偿159%的氧消耗增加。此外,当基于肝脏重量重新表示结果时,这种肝脏氧输送的增加不再明显。(摘要截短于250字)