Colombato L A, Albillos A, Groszmann R J
Hepatic Hemodynamic Laboratory, Veterans Affairs Medical Center, West Haven, Connecticut 06516.
Hepatology. 1992 Feb;15(2):323-8. doi: 10.1002/hep.1840150224.
Peripheral vasodilatation and plasma volume expansion are required to generate the hyperdynamic circulatory state observed in portal hypertension. To determine which of these factors is the initial event and to assess their temporal relationship with the development of hyperdynamic circulation, we sequentially measured plasma volume (by 125I-albumin dilution), cardiac index (by thermodilution), mean arterial pressure (by catheterization), superior mesenteric and iliac arterial flows (by Doppler flowmetry) and calculated total and regional peripheral resistances in portal-hypertensive rats. Experimental groups were studied from day 1 through day 4 after partial portal-vein ligation (n = 110) or sham operation (n = 111). Decreased total peripheral resistance was detected within a day of portal-vein ligation (4.18 +/- 0.21 mm Hg.min.ml-1 x 100 gm vs. 5.19 +/- 0.16 mm Hg.min.ml-1 x 100 gm; p less than 0.01). Plasma volume increased significantly on day 2 (4.31 +/- 0.07 ml.100 gm-1 vs. 3.86 +/- 0.04 ml.100 gm-1; p less than 0.05). Cardiac index and regional blood flows increased in parallel with plasma volume elevation. On day 4, maximum values of plasma volume (4.49 +/- 0.08 ml.100 gm-1 vs. 3.73 +/- 0.03 ml.100 gm-1) coincided with fully developed hyperdynamic circulation, as shown by a significant elevation in cardiac index (32.3 +/- 0.6 ml.min-1 x 100 gm-1 vs. 25.5 +/- 1.2 ml.min-1 x 100 gm-1), iliac and mesenteric blood flow. On day 1, vasodilatation was present in the iliac arterial circulation. In contrast, the superior mesenteric artery vascular bed showed vasoconstriction in response to the protal outflow block.(ABSTRACT TRUNCATED AT 250 WORDS)
外周血管舒张和血浆容量扩张是产生门静脉高压时观察到的高动力循环状态所必需的。为了确定这些因素中哪一个是初始事件，并评估它们与高动力循环发展的时间关系，我们连续测量了门静脉高压大鼠的血浆容量（通过125I-白蛋白稀释法）、心脏指数（通过热稀释法）、平均动脉压（通过导管插入术）、肠系膜上动脉和髂动脉血流（通过多普勒血流仪），并计算了总外周阻力和局部外周阻力。从部分门静脉结扎后第1天至第4天对实验组（n = 110）或假手术组（n = 111）进行研究。门静脉结扎后一天内检测到总外周阻力降低（4.18±0.21 mmHg·min·ml-1×100 g对5.19±0.16 mmHg·min·ml-1×100 g；p<0.01）。第2天血浆容量显著增加（4.31±0.07 ml·100 g-1对3.86±0.04 ml·100 g-1；p<0.05）。心脏指数和局部血流与血浆容量升高平行增加。第4天，血浆容量的最大值（4.49±0.08 ml·100 g-1对3.73±0.03 ml·100 g-1）与完全发展的高动力循环同时出现，表现为心脏指数显著升高（32.3±0.6 ml·min-1×100 g-1对25.5±1.2 ml·min-1×100 g-1）、髂动脉和肠系膜血流增加。第1天，髂动脉循环出现血管舒张。相反，肠系膜上动脉血管床对门静脉流出受阻表现出血管收缩。（摘要截断于250字）
