Cell Biology of Laryngeal Epithelial Defenses in Health and Disease: Preliminary Studies

Abstract

Esophageal epithelium has intrinsic antireflux defenses, including carbonic anhydrases (CAs I to IV) that appear to be protective against gastric reflux. This study aimed to investigate the expression and distribution of CA isoenzymes in laryngeal epithelium. Laryngeal biopsy specimens collected from the vocal fold and interarytenoid regions were analyzed by Western blotting and immunofluorescence. Carbonic anhydrases I and II were expressed by the majority of samples analyzed. In contrast, CA III was differentially expressed in the interarytenoid samples and was not detected in any vocal fold samples. The expression of CA III was increased in esophagitis as compared to normal esophageal tissue. Carbonic anhydrase I and III isoenzymes were distributed cytoplasmically in the basal and lower prickle cell layers. The laryngeal epithelium expresses some CA isoenzymes and has the potential to protect itself against laryngopharyngeal reflux. Laryngeal tissue may be more sensitive to injury due to reflux damage than the esophageal mucosa because of different responses of CA isoenzymes.

Vocal cord dysfunction: what do we know?

“…While it is reported that pH drops below 4 are associated with oesophageal damage, it is recognised that the deleterious actions of pepsin can occur with pH levels as high as 6 [17]. Previous studies have suggested that 50 episodes of reflux are at the upper limits of normal, however three episodes of laryngeal reflux over a week are capable of leading to significant damage in the laryngeal area [23,25,26,27].…”

A pilot study on diagnosing laryngopharyngeal reflux disease by pharyngeal pH probe monitoring

“…Therefore, LPR symptoms might arise, before severity of acidic reflux is not sufficient to induce development of esophagitis. [12] Contrary to GER, complaints of heartburn and regurgitation are not frequently encountered in LPR. [13,14] Ossakow et al [11] reported that patients with complaints of reflux had been either treated in the outpatient clinics of ENT (earnose and throat) (n=63) or gastroenterology (GE) (n=36).…”

Zapalne i nowotworowe zmiany błony śluzowej krtani w chorobie refluksowej

“…Katalizuje ona proces odwracalnej hydratacji dwutlenku węgla a produktem reakcji są między innymi jony wodorowęglanowe alkalizujące środowisko. Wykazano, Ŝe u chorych z LPR ilość CA III spada w przednim odcinku krtani przy jednoczesnym wzroście w tylnym spoidle [119]. Wysunięto hipotezę, Ŝe właśnie duŜa koncentracja CA III w tylnym spoidle krtani moŜe zapobiegać rozwojowi raka, gdyŜ, jak powszechnie wiadomo, rak w tylnym odcinku krtani rozwija się bardzo rzadko [114].…”