[The role of cellular contacts in the recovery of the ion channels of epithelial cell membranes].
Cationic currents in mature MDCK cells are almost exclusively due to K+ channels. Harvesting with trypsin-EDTA destroys 80-90% of these channels. Upon replating, K+ currents recover in 12-20 h, by means a process that requires synthesis of proteins and of RNA. In the present work we demonstrate that this restoration depends on a Ca2+ activated-cell contact. Thus, cells in confluent monolayers bathed with 1.8 mM Ca2+ have a K+ current of 343 +/- 82 pA; confluent without Ca2+ have only 90 +/- 12 pA (27% of control; and without cell-cell contacts incubated with 1.8 mM Ca2+ (subconfl+Ca2+) have 104 +/- 21 pA (31% of control). This demonstration that the expression of K+ channels depends on Ca-activated cell-attaching molecules suggests that a molecule of the type of uvomorulin is involved.
Cereijido
M
M
Centro de Investigación y Estudios Avanzados, México, D.F.
Talavera
D
D
Ponce
A
A
Vega
J
J
García-Villegas
M R
MR
Valdés
J
J
D000818:Animals; D002118:Calcium / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D004285:Dogs; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology; D007668:Kidney / Q000166:cytology / Q000502:physiology; D008564:Membrane Potentials; D008839:Microelectrodes; D018408:Patch-Clamp Techniques / Q000295:instrumentation / Q000379:methods; D015221:Potassium Channels / Q000502:physiology*
D015221:Potassium Channels; D002118:Calcium
El papel de los contactos celulares en la recuperación de canales iónicos de membranas de células epiteliales.