Mechanisms underlying glutamate-induced swelling of astrocytes in primary culture.
The effects of glutamate and its agonists and antagonists on the swelling of primary astrocytes were studied. Glutamate, aspartate, homocysteate, and quisqualate caused a significant increase in astrocytic swelling as measured by 3-0-methyl-[14C]-glucose uptake and by phase-contrast microscopic observations. N-methyl-D-aspartate and kainate were not effective, nor were the competitive NMDA receptor antagonists. Ketamine and MK-801, the non-competitive NMDA receptor antagonists protected the cultured astrocytes against glutamate-induced swelling. Moreover, Glu-induced astrocytic swelling was significantly reduced when sodium-ions were depleted from the culture medium. The sodium ion dependence of Glu-induced astrocytic swelling is rather specific, since depletion of Ca2+ or Mg2+ had no effect. Our data suggest that Na(+)-dependent, Glu-mediated cell swelling occurs in primary cell cultures of astrocytes.
Chan
P H
PH
Department of Neurological Surgery and Neurology, School of Medicine, University of California, San Francisco.
Chu
L
L
D000818:Animals; D001253:Astrocytes / Q000166:cytology* / Q000378:metabolism; D002478:Cells, Cultured; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008858:Microscopy, Phase-Contrast; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013997:Time Factors
D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D007770:L-Lactate Dehydrogenase