Michel R P, Inoue S, Hogg J C
J Appl Physiol Respir Environ Exerc Physiol. 1977 Jan;42(1):13-21. doi: 10.1152/jappl.1977.42.1.13.
Pulmonary capillary permeability was studied in 10 normal anesthetized dogs using horseradish peroxidase (HRP) as tracer. Physiological studies involved measurement of left ventricular, pulmonary arterial, and wedge pressures, and of right lymphatic duct (RLD) and thoracic duct lymph flows. Plasma and interstitial oncotic pressures were calculated from protein measurements. After 1 h of lymph collection, HRP was injected intravenously at three total dose levels, low (20-30 mg/kg), medium (55 mg/kg), and high (110-120 mg/kg) as a bolus followed by smaller doses over 1.5-3 h. HRP was measured colorimetrically in plasma and lymph and appeared in the first RLD lymph sample collected at all dose levels. Electron microscopic studies to examine the passage of HRP from plasma to RLD, while less sensitive in that HRP was seen only at the high dose, showed that it crossed pulmonary capillaries under normal physiological conditions. Freeze-cleaving studies suggest this may have occurred through pathways in the interendothelial space caused by discontinuities in the junctional strands of tight junctions.
以辣根过氧化物酶（HRP）作为示踪剂，对10只正常麻醉犬的肺毛细血管通透性进行了研究。生理学研究包括测量左心室、肺动脉和楔压，以及右淋巴管（RLD）和胸导管淋巴流量。根据蛋白质测量值计算血浆和间质胶体渗透压。在收集淋巴1小时后，以三种总剂量水平静脉注射HRP，低剂量（20 - 30毫克/千克）、中剂量（55毫克/千克）和高剂量（110 - 120毫克/千克），推注后在1.5 - 3小时内给予较小剂量。通过比色法测量血浆和淋巴中的HRP，在所有剂量水平下，首次收集的RLD淋巴样本中均出现了HRP。电子显微镜研究用于检查HRP从血浆到RLD的通道，虽然在高剂量时才观察到HRP，敏感性较低，但显示在正常生理条件下HRP穿过了肺毛细血管。冷冻蚀刻研究表明，这可能是通过紧密连接的连接链中断导致的内皮间隙中的通道发生的。
