Reichelt W, Dettmer D, Brückner G, Brust P, Eberhardt W, Reichenbach A
Carl Ludwig Institute of Physiology, Karl Marx University, DDR, Leipzig.
Cell Signal. 1989;1(2):187-94. doi: 10.1016/0898-6568(89)90009-0.
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.
视网膜神经胶质（穆勒）细胞由出生后早期兔视网膜外植体培养而来。将所得的扁平细胞单层分别暴露于对照培养基（含5.85 mM钾离子）、钾离子浓度升高的培养基（10 mM和20 mM）、精氨酸加压素（AVP，20微克/毫升）或上皮生长因子（EGF，10纳克/毫升）中。通过放射自显影，将蛋白质合成定量为L-[3H]-赖氨酸掺入量，DNA合成定量为[3H]-胸腺嘧啶掺入量。此外，通过放射化学方法测定钠钾ATP酶的活性。短期暴露于中等升高的钾离子浓度（10 mM）或AVP中，可刺激L-[3H]-赖氨酸掺入细胞。长期暴露于高钾离子浓度（20 mM）或EGF中，可刺激[3H]摄取。细胞培养物的钠钾ATP酶活性随培养基中钾离子浓度的增加而升高。提示活跃的神经区室释放钾离子可刺激神经胶质细胞的局部蛋白质合成，从而形成具有活跃钾离子摄取能力的神经胶质鞘。强烈的钾离子释放甚至可能诱导神经胶质细胞增殖。
