Wells U M, Woods A J, Hanafi Z, Widdicombe J G
Department of Physiology, St. George's Hospital Medical School, London, United Kingdom.
J Appl Physiol (1985). 1995 May;78(5):1921-30. doi: 10.1152/jappl.1995.78.5.1921.
Tracheal osmolaity affects blood flow and the flux of a tracer, technetium-99m-labeled diethylenetriamine pentaacetic acid (99mTc-DTPA), from tracheal lumen to venous blood in anesthetized sheep. Hyperosmolar liquids increase blood flow and slightly decrease 99mTc-DTPA flux, whereas hyposmolar liquids have no effect on blood flow and greatly increase 99mTc-DTPA flux. We have now investigated whether epithelial damage induced by exposure of the tracheal lumen to a detergent (0.2% Triton X-100) alters these effects. A tracheal artery was perfused, and tracheal venous blood was collected. The initial tracheal volume was 12.8 +/- 0.7 ml. Triton X-100 greatly increased the permeability coefficient for 99mTc-DTPA from -2.1 x 10(-7) to -240 x 10(-7) cm/s. Hyperosmolar Krebs-Henseleit solution (KH; 739 +/- 6 mosmol/kg) increased arterial (+14.3%) and venous (+21.5%) flows and decreased 99mTc-DTPA output by 51.7%. Water flux into the lumen (+0.3 +/- 0.1 ml) was not significant, and the osmolality decreased by 99 +/- 9 mosmol/kg. Hyposmolar KH (124 +/- 2 mosmol/kg) had no effect on arterial and venous flows (-1.3% for both), and the increase in 99mTc-DTPA output (+8.3%) was small and not significant. The volume decreased by 0.4 +/- 0.1 ml, and the osmolaity increased by 36 +/- 4 mosmol/kg. Thus epithelial damage greatly increases the baseline permeability of the tracheal wall to 99mTc-DTPA. It does not alter the qualitative effects of hypersomolar KH on blood flow and 99mTc-DTPA output but does reduce the effect of hyposmolar KH on 99mTc-DTPA output. The latter effect may be a consequence of the reduced net water movement in response to non-isosmolar solutions after epithelial damage.
气管渗透压会影响麻醉绵羊的血流以及示踪剂（锝 - 99m标记的二乙三胺五乙酸，即99mTc - DTPA）从气管腔到静脉血的通量。高渗液体可增加血流并略微降低99mTc - DTPA通量，而低渗液体对血流无影响，但会大幅增加99mTc - DTPA通量。我们现在研究了气管腔暴露于去污剂（0.2% Triton X - 100）所诱导的上皮损伤是否会改变这些效应。对一条气管动脉进行灌注，并收集气管静脉血。初始气管容积为12.8±0.7毫升。Triton X - 100使99mTc - DTPA的渗透系数从 - 2.1×10⁻⁷大幅增加至 - 240×10⁻⁷厘米/秒。高渗的克雷布斯 - 亨泽莱特溶液（KH；739±6毫摩尔/千克）使动脉血流（增加14.3%）和静脉血流（增加21.5%）增加，并使99mTc - DTPA输出减少51.7%。进入管腔的水通量（+0.3±0.1毫升）不显著，渗透压降低了99±9毫摩尔/千克。低渗KH（124±2毫摩尔/千克）对动脉和静脉血流均无影响（两者均为 - 1.3%），99mTc - DTPA输出的增加（+8.3%）较小且不显著。容积减少了0.4±0.1毫升，渗透压增加了36±4毫摩尔/千克。因此，上皮损伤极大地增加了气管壁对99mTc - DTPA的基线通透性。它不会改变高渗KH对血流和99mTc - DTPA输出的定性影响，但会降低低渗KH对99mTc - DTPA输出的影响。后一种效应可能是上皮损伤后对非等渗溶液的净水移动减少的结果。
