Expression of heat shock protein in the atrophic corneal epithelium of the Royal College of Surgeons dystrophic rat.

We report atrophic changes in the corneal epithelium of Royal College of Surgeons (RCS) dystrophic rats. The thickness of the corneal epithelium of 180-day-old RCS dystrophic rats was significantly decreased compared to that of 26-day-old RCS dystrophic and age-matched Sprague-Dawley (SD) rats. Immunostaining for (Na+ + K+) ATPase in the corneal epithelium of 180-day-old RCS dystrophic rats was dramatically reduced when compared to that of 26-day-old RCS dystrophic and age-matched SD rats. In contrast, heat shock protein immunostaining in the corneal epithelium was dense in all of the basal cells, wing cells, and superficial cells of 180-day-old RCS dystrophic rats but was minimally observed in some of the basal cells and in fewer wing and superficial cells of the corneal epithelium of 26-day-old RCS dystrophic and age-matched SD rats. We speculate that toxic products from the degenerating rod outer segments in the course of retinal dystrophy may affect the corneal epithelium, resulting in its atrophy. It is also possible that heat shock proteins appear in the atrophic corneal epithelium due to its degenerative condition.