Cell volume regulation in cultured cerebellar granule neurons.
Cultured rat cerebellar granule neurons exposed to solutions of reduced osmolarity, responded initially by swelling followed by a regulatory volume decrease (RVD) which is completed within 15 min. Increasing external osmolarity lead to cell shrinking but no evidence of volume regulation was observed within 1 hr. Replacing Na+ by choline did not affect RVD whereas N-methyl-D-glucamine accelerated the volume recovery and K+ suppressed it completely. The blockade of RVD in high extracellular K+ was only observed when chloride and nitrate but not sulfate or gluconate were the accompanying anions. Replacing intracellular Cl-, by long incubations with gluconate, markedly inhibited RVD. Removal of extracellular Ca2+ or addition of dantrolene which blocks Ca2+ released from intracellular stores had no effect on RVD. Increasing extracellular taurine prevented RVD. These results indicate that membrane permeability to K+, Cl-, and taurine is increased by hyposmolarity and suggest the involvement of these molecules in RVD in granule neurons.
Pasantes-Morales
H
H
Institute of Cell Physiology, National University of Mexico, Mexico City.
Maar
T E
TE
Morán
J
J
D000818:Animals; D002118:Calcium / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D002531:Cerebellum / Q000502:physiology / Q000648:ultrastructure*; D002794:Choline / Q000494:pharmacology; D003620:Dantrolene / Q000494:pharmacology; D008536:Meglumine / Q000494:pharmacology; D051379:Mice; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure*; D009994:Osmolar Concentration; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000502:physiology; D013654:Taurine / Q000378:metabolism
D013654:Taurine; D008536:Meglumine; D012964:Sodium; D003620:Dantrolene; D002794:Choline; D011188:Potassium; D002118:Calcium