Porcine Müller glial cells increase expression of BKCa channels in retinal detachment.
OBJECTIVE
To determine whether experimental retinal detachment causes an alteration in Ca2 +-activated, big conductance K+ (BK) currents of Müller glial cells.


METHODS
Rhegmatogenous retinal detachment was induced in porcine eyes. Müller cells were acutely isolated from control retinas and from retinas that were detached for 7 days. BK currents were detected by using the BK channel opener and the blocker phloretin and tetraethylammonium, respectively.


RESULTS
In addition to cellular hypertrophy and a decrease in inward rectifier K+ currents, Müller cells from detached retinas showed an increase in the amplitude of currents mediated by BK channels (850 +/- 105 pA) when compared with cells from control retinas (228 +/- 60 pA; p < 0.001). Similarly, the density of the BK channel-mediated currents was greater in cells from detached retinas (12.32 +/- 1.52 pA/pF) compared with control cells (4.07 +/- 1.07 pA/pF; p < 0.001). The increase in BK currents was correlated with the decrease of the inward rectifier K+ currents.


CONCLUSIONS
It is suggested that an increase in the expression of functional BK channels may be involved in gliotic responses of Müller cells after retinal detachment (e.g., in mitogen-induced Ca2+ responses and cellular proliferation).
Bringmann
Andreas
A
Department of Ophthalmology and Eye Clinic, Faculty of Medicine, University of Leipzig, Liebigstrasse 10-14, D-04103 Leipzig, Germany. bria@medizin.uni-leipzig.de
Iandiev
Ianors
I
Pannicke
Thomas
T
Wurm
Antje
A
Bühner
Eva
E
Reichenbach
Andreas
A
Wiedemann
Peter
P
Uhlmann
Susann
S
D000818:Animals; D004594:Electrophysiology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism*; D008297:Male; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism*; D010693:Phloretin / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism; D012160:Retina / Q000187:drug effects / Q000378:metabolism*; D012163:Retinal Detachment / Q000378:metabolism*; D013552:Swine; D019789:Tetraethylammonium / Q000494:pharmacology; D000098854:Kcnj10 Channel
D000098854:Kcnj10 Channel; D051036:Large-Conductance Calcium-Activated Potassium Channels; D026902:Potassium Channel Blockers; D024661:Potassium Channels, Inwardly Rectifying; D019789:Tetraethylammonium; D010693:Phloretin