Lin W, Jacobs E, Schapira R M, Presberg K, Effros R M
Department of Medicine, Medical College of Wisconsin, Milwaukee 53226, USA.
J Appl Physiol (1985). 1998 Jan;84(1):47-52. doi: 10.1152/jappl.1998.84.1.47.
The stop-flow approach was used to investigate where filtration occurs in the pulmonary vasculature after elevation of left atrial pressure and aspiration of HCl. Rat lungs were perfused for 11 min at zero left atrial pressures, and then flow was stopped for 10 min and left atrial pressures were increased to 20 cmH2O. Thereafter, 3HOH was instilled into the air spaces, and the pulmonary vasculature was flushed by perfusing it from the pulmonary artery to left atrium (anterograde flush) or in the opposite direction (retrograde flush). Increases in fluorescein isothiocyanate (FITC)-dextran (molecular weight 2,000,000) indicated filtration, and these preceded increases in 3HOH after anterograde but not retrograde flushes. This suggests that some filtration occurred through vessels that were relatively venous compared with those through which 3HOH exchange had occurred. Filtration increased fivefold after instillation of 0.1 N HCl in isotonic saline into the air spaces before perfusion. Increases in Evans blue-labeled albumin concentrations were < 40% those of FITC-dextran, indicating loss from the vasculature, but increases in unlabeled albumin and FITC-albumin were comparable.
采用停流法研究左心房压力升高和吸入盐酸后肺血管系统中滤过发生的部位。在左心房压力为零时，对大鼠肺进行11分钟的灌注，然后停流10分钟，并将左心房压力升至20 cmH₂O。此后，将³HOH注入气腔，并通过从肺动脉到左心房的灌注（顺行冲洗）或相反方向（逆行冲洗）对肺血管系统进行冲洗。异硫氰酸荧光素（FITC）-葡聚糖（分子量2,000,000）的增加表明发生了滤过，在顺行冲洗而非逆行冲洗后，³HOH增加之前FITC-葡聚糖就已增加。这表明与³HOH交换发生的血管相比，一些滤过是通过相对静脉性的血管发生的。在灌注前将0.1 N盐酸等渗盐水注入气腔后，滤过增加了五倍。伊文思蓝标记白蛋白浓度的增加不到FITC-葡聚糖的40%，表明有血管内物质丢失，但未标记白蛋白和FITC-白蛋白的增加相当。
