Purpose: Corneal keratocytes are responsible for repairing the corneal stromal matrix after injury or infection. Recent work has characterized the primary voltage-gated ion currents in keratocytes from normal, uninjured corneas. The purpose of the present study was to examine and characterize keratocyte voltage-gated ion currents from freeze-wounded rabbit corneas.
Methods: Rabbit corneas were injured using a liquid nitrogen cooled brass probe. Keratocytes were isolated from control eyes, trephined buttons of stroma encompassing the wound area, and the stromal rim surrounding the button. Ionic currents were examined using the amphotericin perforated-patch variation of the whole cell patch clamp technique.
Results: The delayed rectifier K+ current, described previously as the primary voltage-gated outward current in keratocytes, was found in 100% of control cells, 91% of cells isolated from the corneal rim of wounded cells, and 33% of cells isolated from the wound region. Na+ currents were also seen with a lower frequency in cells from the wound area.
Conclusion: The majority of keratocytes migrating into a corneal freeze wound lose the voltage-gated K+ and Na+ ion channels present in cells from normal corneas. Ion channels from cells surrounding the wound site are minimally affected by the injury.