Briggman J V, Bank H, Graves J S, Spicer S S
Lab Invest. 1983 Jul;49(1):62-8.
The resorption of Na+ and Cl- across the duct of the human eccrine sweat gland is markedly decreased in individuals with cystic fibrosis (CF). Conceivably, a defective transcellular ion transport mechanism or an increased paracellular backflux of ions could account for the abnormal salt resorption in the sweat gland duct and other organs affected in CF. Tight junctions are thought to regulate paracellular ion flow. Specifically, the number of junctional elements observed by freeze fracture are believed to correspond with the extent of paracellular transport. We compared the freeze fracture morphology of tight junctions of eccrine sweat glands taken from 11 control and seven CF patients. In an attempt to "fingerprint" the junctions morphometrically, the following parameters were measured: the number of strands, the depth of the junction from the apical to the basal strand, the angle of intersection between strands, and the mean distance along a strand between intersections with two other strands. No significant difference was observed between control and CF sweat glands in the freeze fracture morphology of the tight junctions of the duct, the segment where the net reabsorption of Na+ and Cl- is abnormally decreased in CF. Significant changes were observed, however, in the means of the number of strands, the depth, and the distance between intersections for the tight junctions of the intercellular canaliculus of the secretory coil, which appears to function normally in CF.
在患有囊性纤维化（CF）的个体中，经人外泌汗腺导管对Na⁺和Cl⁻的重吸收显著降低。可以想象，跨细胞离子转运机制缺陷或细胞旁离子回流量增加可能是CF患者汗腺导管及其他受累器官中盐重吸收异常的原因。紧密连接被认为可调节细胞旁离子流动。具体而言，通过冷冻断裂观察到的连接元件数量被认为与细胞旁转运程度相对应。我们比较了取自11名对照者和7名CF患者的外泌汗腺紧密连接的冷冻断裂形态。为了从形态计量学上“描绘”这些连接，测量了以下参数：股线数量、从顶端股线到基底股线的连接深度、股线之间的交叉角度以及沿着一条股线在与其他两条股线交叉点之间的平均距离。在导管紧密连接的冷冻断裂形态方面，对照者和CF患者的汗腺之间未观察到显著差异，在CF中，导管段Na⁺和Cl⁻的净重吸收异常降低。然而，在分泌盘曲部细胞间小管紧密连接的股线数量、深度和交叉点之间距离的平均值方面观察到了显著变化，而分泌盘曲部在CF中似乎功能正常。
