Dye coupling of rabbit ciliary epithelial cells in vitro.
OBJECTIVE
To examine the in vitro properties of gap junctions on the isolated rabbit ciliary epithelium.


METHODS
Intracellular potential was measured and lucifer yellow (5% in 1 M LiCl) was iontophoretically injected into a ciliary epithelial cell. Fixated tissue was examined with a laser confocal microscope.


RESULTS
Dye spread was observed throughout both layers (horizontally and vertically) of the ciliary epithelium adjacent to the injected cell that was more intensely labeled. Dye reflux did not occur at the site of microimpalement. Microiontophoretic dye injection in a bathing solution with a high Ca2+ (10 mM) or an acidic pH (6.3) completely inhibited cell-cell dye coupling in the rabbit ciliary epithelial cells.


CONCLUSIONS
Laser confocal microscopy of intracellularly injected lucifer yellow dye demonstrates the physiologic presence of gap junctions between both ciliary epithelial layers. Extracellular acidosis and high concentration of extracellular Ca2+ cause loss of cell-cell coupling in the rabbit ciliary epithelium.
Oh
J
J
Department of Ophthalmology, Northwestern University Medical School, Chicago, Illinois 60611.
Krupin
T
T
Tang
L Q
LQ
Sveen
J
J
Lahlum
R A
RA
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002924:Ciliary Body / Q000378:metabolism* / Q000648:ultrastructure; D004848:Epithelium / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D017629:Gap Junctions / Q000378:metabolism*; D007478:Iontophoresis; D007546:Isoquinolines / Q000378:metabolism*; D008564:Membrane Potentials; D008856:Microscopy, Fluorescence; D010477:Perfusion; D011817:Rabbits
D005456:Fluorescent Dyes; D007546:Isoquinolines; C017475:lucifer yellow; D002118:Calcium