Kosaku, Kazuhiro, Tomonori Harada, Toyoharu Jike, Isao Tsuboi, and Shin Aizawa. Long-term hypoxic tolerance in murine cornea. High Alt Med Biol 19:35-41, 2018.
Aims: The cornea is believed to be an exceedingly sensitive organ to decreases in atmospheric oxygen concentrations. Previous corneal studies have shown the hypoxic tolerance of the cornea during short-term and local hypoxic exposure. This study investigated the tolerance of the cornea during long-term and systemic hypoxia.
Methods and results: Mice were bred under normobaric normoxia or hypoxia (10% oxygen concentration) conditions for 140 days. The layer structure, surface microvilli, and glycogen granules in the corneal epithelium were examined on day 2 and on day 140. The layer and surface structures of the corneal epithelium were normally maintained during the long-term hypoxia. Hypoxic stress caused a decrease in the glycogen granules in the corneal epithelial cells.
Conclusions: Maintenance of normal structures during long-term hypoxia suggests that the cornea has a high tolerance for hypoxic stress. The quantity of glycogen in corneal epithelial cells is considered an index of corneal hypoxia resistance.
Keywords: cornea; glycogen; long-term; systemic hypoxia.