Siegenbeek van Heukelom J, van den Ham M D, Albus H, Groot J A
J Membr Biol. 1981;63(1-2):31-9. doi: 10.1007/BF01969443.
The rate of shrinkage of the mucosal folds of goldfish intestine in response to mucosal hypertonicity was measured by microscopic means. Because of the geometry of the intestinal folds the rate of shrinkage could be directly related to the loss of volume from the fold through the brush border membranes and tight junctions. Experimentally a wide range of velocities was observed, reflecting the difficulty of rapidly establishing a uniform osmotic gradient at the preparation's mucosal surface. The initial velocity of volume loss provided a measure of the filtration permeability (Pf) of the mucosal surface. From the highest velocities observed the filtration permeability was estimated to be approximately 14 X 10(-3) cm/sec related to the folded mucosal surface and 65 X 10(-3) cm/sec related to the straight serosal surface. Consideration of the experimental errors and unstirred layer effects make it probable that the latter value is still an underestimate of the true Pf. The series barriers of the epithelium cause the total tissue Pf to be less than the Pf of the mucosal surface alone. In addition the Pf measured in the presence of an osmotic gradient may differ substantially from the tissue filtration permeability which exists in the absence of a change in osmolarity.
采用显微镜测量法，测定金鱼肠道黏膜皱襞对黏膜高渗性的收缩速率。由于肠道皱襞的几何形状，收缩速率可直接与通过刷状缘膜和紧密连接从皱襞中损失的体积相关。实验中观察到了广泛的速率范围，这反映了在制剂黏膜表面快速建立均匀渗透梯度的困难。体积损失的初始速率提供了黏膜表面过滤渗透率（Pf）的一种度量。根据观察到的最高速率，估计与折叠的黏膜表面相关的过滤渗透率约为14×10⁻³厘米/秒；与直的浆膜表面相关的过滤渗透率为65×10⁻³厘米/秒。考虑到实验误差和未搅动层效应，后一个值很可能仍然低估了真实的Pf。上皮细胞的一系列屏障导致整个组织的Pf小于仅黏膜表面的Pf。此外，在存在渗透梯度的情况下测得的Pf可能与在渗透压无变化时存在的组织过滤渗透率有很大差异。
