Dye coupling in the corneal endothelium: effects of ouabain and extracellular calcium removal.
The effects of ouabain and extracellular calcium removal on gap junctional coupling of isolated rabbit corneal endothelium was examined using a modified dye-spread technique. This technique is a modification of a microelectrode procedure that now utilizes patch electrodes connected to a current-clamp circuit for dye iontophoresis and a shuttering system in the excitation light path to reduce phototoxic effects in the monolayer. It was found that a significant degree of junctional uncoupling occurred after 45 min of exposure to ouabain, quantified as a reduction in the effective diffusion coefficient of injected Lucifer yellow CH: 1.74 x 10(-7) cm2/s (control) versus 0.43 x 10(-7) cm2/s (ouabain-treated). It was also determined that no gap junctional uncoupling occurs after extended exposure (up to 3.5 h) to a calcium-free extracellular environment.
Watsky
M A
MA
Department of Physiology and Biophysics, Mayo Foundation, Rochester, MN 55905.
Rae
J L
JL
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002450:Cell Communication; D002478:Cells, Cultured; D004728:Endothelium, Corneal / Q000187:drug effects / Q000378:metabolism*; D007365:Intercellular Junctions / Q000378:metabolism*; D007546:Isoquinolines; D008845:Microinjections; D010042:Ouabain / Q000494:pharmacology*; D011817:Rabbits
D007546:Isoquinolines; D010042:Ouabain; C017475:lucifer yellow; D002118:Calcium