Expression of ENaC subunits in sensory nerve endings in the rat larynx.
We investigated the expression of three subunits of epithelial sodium channel (ENaC), alphaENaC, betaENaC and gammaENaC, in the nodose ganglion and laryngeal mucosa of rat by RT-PCR analysis and immunohistochemistry. PCR products of predicted size for alphaENaC, betaENaC and gammaENaC subunits were amplified from extract of nodose ganglion. Immunohistochemically, nodose ganglion neurons of medium to large diameter were immunoreactive for alphaENaC, betaENaC and gammaENaC. In the deep region of laryngeal submucosal layer, thick nerve fibers without varicosities were immunoreactive for alphaENaC, betaENaC and gammaENaC. In the laryngeal mucosa, terminal arborizations of the nerve endings, that immunoreacted for alphaENaC, betaENaC and gammaENaC were scattered in the lamina propria just beneath the epithelia of epiglottis and laryngeal vestibule. Double immunofluorescence with calretinin revealed that they were laminar nerve endings. Some thick nerve fibers near the laryngeal taste buds were also immunoreactive for betaENaC and gammaENaC, but negative for alphaENaC. In the larynx, ENaC channels may play important roles in mechanotransduction in the laminar endings and in the mechano- and chemotransductions in the taste bud-associated nerve fibers.
Yamamoto
Yoshio
Y
Laboratory of Veterinary Anatomy, Department of Veterinary Sciences, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan. yyoshio@iwate-u.ac.jp
Taniguchi
Kazuyuki
K
D000818:Animals; D053503:Epithelial Sodium Channels; D005260:Female; D007150:Immunohistochemistry; D007820:Laryngeal Mucosa / Q000294:innervation / Q000378:metabolism; D007823:Laryngeal Nerves / Q000378:metabolism*; D007830:Larynx / Q000378:metabolism*; D008297:Male; D040542:Mechanotransduction, Cellular; D009474:Neurons / Q000378:metabolism; D009620:Nodose Ganglion / Q000378:metabolism; D021122:Protein Subunits / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D011984:Sensory Receptor Cells / Q000378:metabolism*; D015222:Sodium Channels / Q000096:biosynthesis* / Q000235:genetics
D053503:Epithelial Sodium Channels; D021122:Protein Subunits; D012333:RNA, Messenger; D015222:Sodium Channels