title: Tight junction-related barrier contributes to the electrophysiological asymmetry across vocal fold epithelium.
abstract: Electrophysiological homeostasis is indispensable to vocal fold hydration. We investigate tight junction (TJ)-associated components, occludin and ZO-1, and permeability with or without the challenge of a permeability-augmenting agent, histamine. Freshly excised ovine larynges are obtained from a local abattoir. TJ markers are explored via reverse transcriptase polymerase chain reaction (RT-PCR). Paracellular permeabilities are measured in an Ussing system. The gene expression of both TJ markers is detected in native ovine vocal fold epithelium. Luminal histamine treatment significantly decreases transepithelial resistance (TER) (N = 72, p<0.01) and increases penetration of protein tracer (N = 35, p<0.001), respectively, in a time-, and dose-dependent fashion. The present study demonstrates that histamine compromises TJ-related paracellular barrier across vocal fold epithelium. The detection of TJ markers indicates the existence of typical TJ components in non-keratinized, stratified vocal fold epithelium. The responsiveness of paracellular permeabilities to histamine would highlight the functional significance of this TJ-equivalent system to the electrophysiological homeostasis, which, in turn, regulates the vocal fold superficial hydration.
authors.affiliation: Experimental Center of Functional Subjects, College of Basic Science, China Medical University, Shenyang, Liaoning, China. qianruzhang2008@u.northwestern.edu
authors.forename: Qianru
authors.initials: Q
authors.lastname: Zhang
authors.forename: Kimberly
authors.initials: K
authors.lastname: Fisher
mesh_terms: D000818:Animals; D055724:Electrophysiological Phenomena; D005786:Gene Expression Regulation / Q000502:physiology; D007820:Laryngeal Mucosa / Q000166:cytology / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis; D062793:Occludin; D010539:Permeability; D010750:Phosphoproteins / Q000096:biosynthesis; D012756:Sheep; D019108:Tight Junctions / Q000378:metabolism*; D014827:Vocal Cords / Q000166:cytology / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein
chemical_list: D008565:Membrane Proteins; D062793:Occludin; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein