Grossman H J, Grossman V L, Bhathal P S
Department of Pathology, University of Melbourne, Parkville, Victoria, Australia.
J Gastroenterol Hepatol. 1995 Jul-Aug;10(4):459-64. doi: 10.1111/j.1440-1746.1995.tb01600.x.
The effect of altered vascular tone on the haemodynamic characteristics of the intrahepatic portal vascular bed was studied in the isolated perfused rat liver preparation. The relationship between portal venous inflow (Q) and portal perfusion pressure (P) was determined in the presence of a maximally effective concentration of a vasoconstrictor agent (noradrenaline, NAmax, 3 x 10(-5)mol/L), an intermediate concentration (NAmed, 1 x 10(-6)mol/L) or a vasodilator agent (papaverine, PAP, 6 x 10(-4)mol/L). At flow rates greater than 20 mL/min, the pressure-flow relationship could be regarded as linear (P < 0.001), with mean values for the extrapolated intercept with the pressure axis (Po) of 6.8 +/- 0.9 mmHg for NAmax, 4.5 +/- 0.5 mmHg for NAmed, and 1.65 +/- 0.05 mmHg for PAP-treated preparations. Over the full flow range (0-70 mL/min), in both NA- and PAP-treated preparations, portal vascular conductance (G = Q/P) was related directly to perfusion pressure. Thus, G = C.P, where C is a constant (mean values for NAmax, NAmed, and PAP-treated preparations were 0.0090 +/- 0.0020, 0.023 +/- 0.005, and 0.26 +/- 0.02 mL/min per g per mmHg2, respectively). It is concluded that both C and Po may be useful indices of tone in the isolated perfused rat liver, and that analysis of hepatic portal haemodynamics in this manner may have considerable practical value in studies of the action of vasoactive agents.
在离体灌注大鼠肝脏标本中，研究了血管张力改变对肝内门静脉血管床血流动力学特性的影响。在存在最大有效浓度的血管收缩剂（去甲肾上腺素，NAmax，3×10⁻⁵mol/L）、中等浓度（NAmed，1×10⁻⁶mol/L）或血管扩张剂（罂粟碱，PAP，6×10⁻⁴mol/L）的情况下，测定门静脉流入量（Q）与门静脉灌注压（P）之间的关系。在流速大于20 mL/min时，压力-流量关系可视为线性关系（P<0.001），NAmax处理组、NAmed处理组和PAP处理组外推至压力轴的截距（Po）平均值分别为6.8±0.9 mmHg、4.5±0.5 mmHg和1.65±0.05 mmHg。在整个流量范围内（0 - 70 mL/min），无论是NA处理组还是PAP处理组，门静脉血管传导率（G = Q/P）均与灌注压直接相关。因此，G = C·P，其中C为常数（NAmax处理组、NAmed处理组和PAP处理组的平均值分别为0.0090±0.0020、0.023±0.005和0.26±0.02 mL/min·g·mmHg²）。结论是，C和Po都可能是离体灌注大鼠肝脏中血管张力的有用指标，并且以这种方式分析肝门静脉血流动力学在血管活性药物作用的研究中可能具有相当大的实用价值。
