Gap junction change in supporting cells of the organ of Corti with ryanodine and caffeine.
It has been demonstrated that the gap junctions of the supporting cells of the organ of Corti are controlled by H+ and Ca2+. Inside these cells there is a tubular structure. It is supposed that this network is endoplasmic reticulum. Calcium release from inside the cells, and the effect of calcium on the gap junctions of these cells, were investigated under whole cell clamping application of ryanodine and caffeine. Membrane capacitance and membrane resistance were calculated, with corrections for changes in whole cell parameters. Ryanodine-treated cells (1 microM-10 mM), caffeine-treated cells (5 mM 500 nM) and A23187-treated cells were uncoupled at their gap junctions. Therefore, Ca2+ plays a role in the uncoupling of the gap junctions in supporting cells of the organ of Corti from inside the cells.
Sato
Y
Y
Sato ENT Clinic (Okayama), Japan. sato-y@pp.iij4u.or.jp
Handa
T
T
Matsumura
M
M
Orita
Y
Y
D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000502:physiology; D015220:Calcium Channels / Q000187:drug effects*; D020013:Calcium Signaling / Q000187:drug effects*; D002462:Cell Membrane / Q000502:physiology; D004553:Electric Conductivity; D017097:Electric Impedance; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000648:ultrastructure; D017629:Gap Junctions / Q000187:drug effects* / Q000648:ultrastructure; D006168:Guinea Pigs; D006859:Hydrogen / Q000502:physiology; D007476:Ionophores / Q000494:pharmacology; D007760:Labyrinth Supporting Cells / Q000187:drug effects* / Q000648:ultrastructure; D009925:Organ of Corti / Q000187:drug effects* / Q000648:ultrastructure; D018408:Patch-Clamp Techniques; D012433:Ryanodine / Q000494:pharmacology*; D014475:Uncoupling Agents / Q000494:pharmacology
D015220:Calcium Channels; D007476:Ionophores; D014475:Uncoupling Agents; D012433:Ryanodine; D000001:Calcimycin; D002110:Caffeine; D006859:Hydrogen; D002118:Calcium