title: Potassium as a signal for both proliferation and differentiation of rabbit retinal (Müller) glia growing in cell culture.
abstract: Retinal glial (Müller) cells were grown from explants of early postnatal rabbit retinae. The resulting monolayers of flat cells were exposed to control media (containing 5.85 mM K+), and to media with enhanced K+ concentrations (10 and 20 mM) or arginine-vasopressin (AVP, 20 micrograms/ml) or epithelial growth factor (EGF, 10 ng/ml). Autoradiographically, protein synthesis was quantified as L-[3H]-lysine incorporation, and DNA synthesis as [3H]-thymidine incorporation. Furthermore, the activity of Na+,K(+)-ATPase was measured radiochemically. Short exposure to either moderately enhanced K+ concentrations (10 mM) or to AVP, stimulated L-[3H]-lysine incorporation into the cells. Long-lasting exposure to either high K+ concentrations (20 mM) or to EGF stimulated [3H]-uptake. The Na+,K(+)-ATPase activity of cell cultures increased with increasing K+ concentration of the media. It is suggested that release of K+ by active neuronal compartments stimulates local protein synthesis of glial cells, resulting in the formation of glial sheaths with active K+ uptake capacity. Strong K+ release may even induce glial proliferation.
authors.affiliation: Carl Ludwig Institute of Physiology, Karl Marx University, DDR, Leipzig.
authors.forename: W
authors.initials: W
authors.lastname: Reichelt
authors.forename: D
authors.initials: D
authors.lastname: Dettmer
authors.forename: G
authors.initials: G
authors.lastname: Brückner
authors.forename: P
authors.initials: P
authors.lastname: Brust
authors.forename: W
authors.initials: W
authors.lastname: Eberhardt
authors.forename: A
authors.initials: A
authors.lastname: Reichenbach
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D008239:Lysine / Q000378:metabolism; D009457:Neuroglia / Q000166:cytology* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D011817:Rabbits; D012160:Retina / Q000166:cytology* / Q000378:metabolism; D015398:Signal Transduction; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism
chemical_list: D001127:Arginine Vasopressin; D004247:DNA; D000254:Sodium-Potassium-Exchanging ATPase; D008239:Lysine; D011188:Potassium; D013936:Thymidine