Allen D, Korthuis R J, Clark S
University of Georgia, College of Veterinary Medicine, Department of Large Animal Medicine, Athens 30602.
J Appl Physiol (1985). 1988 Apr;64(4):1580-3. doi: 10.1152/jappl.1988.64.4.1580.
A pump-perfused extracorporeal digital preparation was used to evaluate blood flow, arterial pressure, venous pressure, isogravimetric capillary filtration coefficient, capillary pressure, and vascular compliance in six normal horses. From these data, pre- and postcapillary resistances and pre- and postcapillary resistance ratios were determined. Vascular and tissue oncotic pressures were estimated from plasma and lymph protein concentrations, respectively. By use of the collected and calculated data, tissue pressure in the digit was calculated using the Starling equation. In the isolated equine digit, isogravimetric capillary pressure averaged 36.7 mmHg, plasma and lymph oncotic pressures averaged aged 19.12 and 6.6 mmHg, respectively, interstitial fluid pressure averaged 25.6 mmHg, and the capillary filtration coefficient averaged 0.0013 ml.min-1.mm-1.100 g-1. Our results indicate that digital capillary pressure in the laterally recumbent horse is much higher than in analogous tissues in other species such as dog and human. However, the potential edemagenic effects of this high digital capillary pressure are opposed by at least two mechanisms: 1) a high tissue pressure and 2) a low microvascular surface area for fluid exchange and/or a low microvascular permeability to filtered fluid.
采用泵灌注的体外数字模型，对6匹正常马的血流、动脉压、静脉压、等重力毛细血管滤过系数、毛细血管压和血管顺应性进行评估。根据这些数据，确定毛细血管前、后阻力以及毛细血管前、后阻力比。血管和组织胶体渗透压分别根据血浆和淋巴蛋白浓度估算。利用收集和计算的数据，采用斯塔林方程计算指部组织压力。在离体马指中，等重力毛细血管压平均为36.7 mmHg，血浆和淋巴胶体渗透压平均分别为19.12和6.6 mmHg，组织间隙液压力平均为25.6 mmHg，毛细血管滤过系数平均为0.0013 ml·min⁻¹·mm⁻¹·100 g⁻¹。我们的结果表明，侧卧马的指部毛细血管压远高于狗和人等其他物种的类似组织。然而，这种高指部毛细血管压的潜在致水肿作用至少受到两种机制的对抗：1）高组织压力；2）用于液体交换的微血管表面积低和/或微血管对滤过液的通透性低。
