Vargas F F, Blackshear G L
Am J Physiol. 1981 Apr;240(4):H457-64. doi: 10.1152/ajpheart.1981.240.4.H457.
We evaluated secondary hydrostatic and osmotic pressure gradients caused by an osmotic flow across the wall of rabbit heart capillaries in vitro. Tissue fluid loss after addition of 80 mM sucrose to the Ringer perfusate depressed interstitial fluid pressure (IFP) by 13.2 +/- 1.1 cmH2O, as measured with a fine intramyocardial needle. This, plus a calculated rise in capillary pressure, caused a difference of 4.3 cmH2O in transcapillary pressures which represents 1.4% of the simultaneous and opposite osmotic pressure difference. The effect of transient-induced experimental changes in interstitial effect of transient-induced experimental changes in interstitial concentration of NaCl (main resident solute) during an osmotic transient and osmotic balance experiments using opposing transcapillary flows (Jv) and a sigma sucrose = 2.9 sigma NaCl. Long-term perfusion with solutions having abnormal concentrations of NaCl did not influence Jv, whereas inclusions of sucrose as resident solute depressed Jv by 10%. Results indicate that secondary hydrostatic and osmotic forces are small relative to the main osmotic driving force. Compliance measurements and calculations suggest that cells contribute three-fourths organ water loss during an osmotic transient, thus buffering volume, pressure, and concentration changes in the interstitial spaces.
我们在体外评估了兔心毛细血管壁上渗透流引起的继发性静水压和渗透压梯度。在用林格氏灌流液灌注时添加80 mM蔗糖后，组织液流失使心肌内细针测量的组织间液压力（IFP）降低了13.2±1.1 cmH₂O。这一点，再加上计算得出的毛细血管压力升高，导致跨毛细血管压力差为4.3 cmH₂O，这占同时存在的相反渗透压差值的1.4%。在使用相反的跨毛细血管流（Jv）且σ蔗糖 = 2.9σ氯化钠的渗透瞬变和渗透平衡实验中，瞬时诱导的间质中氯化钠（主要驻留溶质）浓度实验变化的间质效应。用氯化钠浓度异常的溶液进行长期灌注不影响Jv，而作为驻留溶质加入蔗糖会使Jv降低10%。结果表明，相对于主要渗透驱动力而言，继发性静水压和渗透力较小。顺应性测量和计算表明，在渗透瞬变期间，细胞贡献了器官四分之三的水分流失，从而缓冲了组织间隙中的体积、压力和浓度变化。
