Abstract
Purpose::
Oral ecabet sodium is a gastroprotective drug with an excellent safety profile. Oral ecabet sodium enhances gastric mucous secretion and is indicated for the treatment of gastric ulcers. The gel-forming mucin, MUC5AC, is secreted from both the epithelium of the stomach and the conjunctival goblet cells. Importantly, MUC5AC maintains the stability of tear film on the ocular surface and the amount of MUC5AC in dry eye patients is lower compared to normal volunteers. We evaluated the effect of topical ecabet sodium on the secretion of MUC5AC in rabbit tears.
Methods::
In a crossover study, either ecabet sodium ophthalmic solution 3% or physiological saline was instilled in one rabbit eye. Right after instillation, the tear fluid was collected by gently forced blinking. Next day, the remaining test agent was instilled in the same rabbit and the tear fluid was collected. Proteins in the constant volume of tear fluid were separated by agarose gel electrophoresis and MUC5AC was detected by anti-MUC5AC antibody using vacuum blotting method. The amount of MUC5AC was compared in the same eye between ecabet sodium ophthalmic solution 3% and physiological saline. The immunoreactivity of the antibody was confirmed by immunostaining of goblet cells in rabbit conjunctival frozen section.
Results::
Ecabet sodium ophthalmic solution 3% significantly increased the amount of MUC5AC in rabbit tears compared to physiological saline (one-sided paired t-test, p<0.05). Immunostaining demonstrated that the rabbit conjunctival goblet cells were stained by the antibody against MUC5AC.
Conclusions::
Ecabet sodium increased the amount of MUC5AC and its onset of action is very quick compared to placebo. This study strongly suggests that ecabet sodium may promote MUC5AC secretion in humans and may offer an effective treatment for dry eyes.
Keywords: cornea: surface mucins • cornea: tears/tear film/dry eye • glycoconjugates/glycoproteins