The corneal epithelium is crucial for maintaining ocular surface homeostasis.
Understanding its electrical properties is key to comprehending corneal function and disease.
Purpose of the Study:
To investigate the electrical potentials and resistances of rabbit corneal epithelial cell membranes.
To elucidate the contribution of individual membrane potentials to the overall corneal electrical potential.
Main Methods:
Utilized 3 M-KCl-filled micro-electrodes for potential and resistance measurements.
Employed iontophoretic dye injection to localize potential steps across epithelial layers.
Performed experiments on both isolated corneas and living rabbit eyes.
Main Results:
Identified three distinct potential steps across the rabbit corneal epithelium, localized to specific cell membranes.
The outer epithelial membrane accounted for 60% of the total corneal resistance.
Stromal potential was found to be positive to the tear side, contrary to some previous reports.
Demonstrated that loop currents significantly contribute to potential distribution within the epithelium.
Observed differences in major resistance sites between rabbit and frog corneal epithelia.
Conclusions:
The outer membrane of the squamous cell is the primary determinant of corneal electrical resistance in rabbits.
Loop currents play a significant role in generating potential differences across the corneal epithelium.
Established a detailed electrophysiological profile of the rabbit corneal epithelium, with implications for understanding ion transport and barrier function.