Payne D K, Kinasewitz G T, Gonzalez E
Department of Medicine, Louisiana State University Medical Center, Shreveport 71130-3932.
J Appl Physiol (1985). 1988 Dec;65(6):2558-64. doi: 10.1152/jappl.1988.65.6.2558.
To determine the permeability of canine pleural mesothelium, visceral and intercostal parietal pleura from mongrel dogs was carefully stripped from the underlying tissue and mounted as a planar sheet in a Ussing-type chamber. The hydraulic conductivity (Lp) was determined from the rate of volume flux in response to hydrostatic pressure gradients applied to either the mucosal or serosal surface of the pleural membrane. The diffusional permeability (Pd) of radiolabeled water, sucrose, inulin, and albumin was determined under equilibrium conditions from the unidirectional tracer flux. The Lp of the visceral pleura was 0.39 +/- 0.032 (SE) X 10(-4) ml.s-1.cmH2O-1.cm-2 and that Lp of parietal pleura was 1.93 +/- 0.93 X 10(-4) ml.s-1.cmH2O-1.cm-2 (P less than 0.001). The Pd of the visceral pleura ranged from 12.21 +/- 0.45 X 10(-4) cm/s for 3H2O to 0.34 +/- 0.03 X 10(-4) cm/s for [3H]albumin. The Pd of the parietal pleura for water and sucrose was similar to that of the visceral membrane, whereas its Pd for the larger inulin and albumin molecules was greater than that of visceral pleura (P less than 0.01). A spontaneous potential difference could not be detected across either membrane. The relatively higher parietal pleural Lp and Pd for larger solutes is probably due to the presence of stomata in this membrane. These results indicate that both the parietal and the visceral pleura are extremely permeable tissues which offer little resistance to water and solute flux.
为了测定犬胸膜间皮的通透性，从杂种犬身上小心剥离脏层和肋间壁层胸膜下的组织，并将其作为平面片安装在Ussing型小室中。根据施加于胸膜黏膜或浆膜表面的静水压力梯度下的体积通量速率来测定水力传导率（Lp）。在平衡条件下，根据单向示踪剂通量测定放射性标记水、蔗糖、菊粉和白蛋白的扩散通透性（Pd）。脏层胸膜的Lp为0.39±0.032（标准误）×10⁻⁴ ml·s⁻¹·cmH₂O⁻¹·cm⁻²，壁层胸膜的Lp为1.93±0.93×10⁻⁴ ml·s⁻¹·cmH₂O⁻¹·cm⁻²（P<0.001）。脏层胸膜的Pd范围从³H₂O的12.2 ± 0.45×10⁻⁴ cm/s到[³H]白蛋白的0.34±0.03×10⁻⁴ cm/s。壁层胸膜对水和蔗糖的Pd与脏层膜相似，而其对较大的菊粉和白蛋白分子的Pd大于脏层胸膜（P<0.01）。在任何一层膜上均未检测到自发电位差。壁层胸膜对较大溶质的Lp和Pd相对较高可能是由于该膜中存在气孔。这些结果表明，壁层和脏层胸膜都是极易渗透的组织，对水和溶质通量几乎没有阻力。
