The structure of tight junctions in the tracheal epithelium may not correlate with permeability

Abstract

To test the hypothesis that cigarette smoke produces changes in the morphology of tight junctions guinea pigs were exposed to cigarette smoke or air in a previously standardized fashion (Simani et al. 1974). Permeability is greatest one half hour following exposure to cigarette smoke (Hulbert et al. 1981). The animals were sacrificed at that time. The tracheal epithelium was studied using both thin-section and freeze-fracture techniques. A quantitative analysis of the organization and integrity of junctional complexes was performed for each animal. Organization was assessed by measuring and comparing areas delimited by PF fibers and EF furrows. PF fiber integrity was assessed by measuring uninterrupted lengths of fibers and furrows from freeze-fracture replicas. This assessment did not demonstrate a change in tight-junction morphology following exposure to cigarette smoke.

Human airway epithelial tight junctions

“…A number of workers have stressed a possible role for epithelial tight junctions in the development of chronic bronchitis (Hulbert et al, 1981;Walker et al, 1984), asthma (Devalia et al, 1994;Boucher et al, 1978;Braude et al, 1984), and cystic fibrosis (Boucher et al, 1983;Geddes, 1990). However, owing to the difficulty in obtaining physiological measurements on the function of human airway epithelial tight junctions in vivo, little data to support these hypotheses have been published.…”

Role of claudin interactions in airway tight junctional permeability

“…Several studies have investigated the role for airway epithelial TJs in the development of chronic disease (3,5,11,18,27). These studies have largely focused on TJ ultrastructure in diseased lungs, and most work investigating the correlation between the diseased airway and TJ ultrastructure has been conducted in patients with cystic fibrosis (CF) (7,16).…”

A Re-Assessment of the Tricellular Region of Epithelial Cell Tight Junctions in Trachea of Guinea Pig

“…The observation that increased tracheal epithelial permeability may not be accompanied by disruption of tight junctions along lateral surfaces of adjacent epithe lial cells [Walker et al, 1984] led us to re-examine tricel lular junctions where three cells meet. In the course of studying the epithelial tight junctions from the tracheas of at least 10 guinea pigs and from the lungs of 12 mon grel dogs, we have observed a number of tricellular regions of tight junctions.…”