Gore R W
Am J Physiol. 1982 Feb;242(2):H268-87. doi: 10.1152/ajpheart.1982.242.2.H268.
Previous studies suggest that large differences exist among fluid exchange parameters in the mesenteric, muscle, and mucosal regions of the small intestine. However, few quantitative data from the separate regions, with the exception of the mesentery, are available for comparison. In this study, quantitative measurements of hydraulic conductivities (LP) and occluded effective pressures (P'e) were made on single capillaries in rat intestinal muscle. The microcirculation of longitudinal intestinal muscle was viewed through a microscope using the method of Bohlen and Gore. The single-occlusion method of Lee, Smaje, and Zweifach was used to estimate LP and P'e in single capillaries. Details of the procedures for analyzing the experimental data using the Lee analytical model are included in an APPENDIX. Measurements were made at four different sites in each capillary studied so gradients in LP could be quantitated and variations in P'e could be detected. The average LP at the venous end of the capillaries was nearly seven times greater than LP at the arterial end. The average LP at the arterial end [18.6 +/- 2.3(SE)% of the distance (%L/Lo) from the fifth-order arterioles] was 1.32 +/- 0.4 X 10(-2) micrometers.s-1.cmH2O-1. The average LP at the venous end (%L/Lo = 81.7 +/- 2.2%) was 9.15 +/- 0.34 X 10(-2) micrometers.s-1.cmH2O-1. Values of LP at intermediate capillary locations 39.9 +/- 2.3 and 61.3 +/- 3.2% were 2.17 +/- 0.34 and 4.48 +/- 0.62 X 10(-2) micrometers.s-1.cmH2O-1, respectively. The total mean LP for all the data (132 samples, 33 capillaries, 10 rats) was 4.19 +/- 0.61 X 10(-2) micrometers.s-1.cmH2O-1. Comparison of these data with results from other tissues indicates that LP of intestinal muscle capillaries is 1.7 times greater than LP of omental capillaries and three times greater than LP of mesenteric capillaries. Values of P'e were corrected for the unoccluded state and were used to calculate total transcapillary pressures (delta P). The results suggested that the intestinal muscle layers were well hydrated and that tissue hydrostatic pressures were positive. Transcapillary fluid fluxes (JVo) at different sites on the capillaries were estimated from the relationship, JVo = LP X delta P. The results imply that intestinal muscle capillaries are primarily an absorptive network when systemic arterial pressure and capillary pressures are normal.
先前的研究表明，小肠系膜、肌肉和黏膜区域的液体交换参数存在很大差异。然而，除了肠系膜外，来自其他单独区域的定量数据很少，无法进行比较。在本研究中，对大鼠肠肌中的单个毛细血管进行了水力传导率（LP）和闭塞有效压力（P'e）的定量测量。使用博伦和戈尔的方法，通过显微镜观察纵向肠肌的微循环。采用李、斯马杰和茨魏法赫的单闭塞法来估计单个毛细血管中的LP和P'e。使用李分析模型分析实验数据的程序细节包含在附录中。在每个研究的毛细血管的四个不同部位进行测量，以便能够定量LP的梯度并检测P'e的变化。毛细血管静脉端的平均LP几乎是动脉端LP的七倍。动脉端的平均LP[距五级小动脉距离（%L/Lo）的18.6±2.3（SE）%]为1.32±0.4×10⁻²微米·秒⁻¹·厘米水柱⁻¹。静脉端的平均LP（%L/Lo = 81.7±2.2%）为9.15±0.34×10⁻²微米·秒⁻¹·厘米水柱⁻¹。毛细血管中间位置39.9±2.3%和61.3±3.2%处的LP值分别为2.17±0.34和4.48±0.62×10⁻²微米·秒⁻¹·厘米水柱⁻¹。所有数据（132个样本，33根毛细血管，10只大鼠）的总平均LP为4.19±0.61×10⁻²微米·秒⁻¹·厘米水柱⁻¹。将这些数据与其他组织的结果进行比较表明，肠肌毛细血管的LP比网膜毛细血管的LP大1.7倍，比肠系膜毛细血管的LP大三倍。对P'e的值进行了未闭塞状态的校正，并用于计算总跨毛细血管压力（ΔP）。结果表明肠肌层水分充足，组织静水压为正。根据JVo = LP×ΔP的关系估计毛细血管不同部位的跨毛细血管液体通量（JVo）。结果表明，当全身动脉压和毛细血管压力正常时，肠肌毛细血管主要是一个吸收性网络。
