Association between cell swelling and glycogen content in cultured astrocytes.
Treatment of cultured rat astrocytes with hypotonic media or with 1 mM glutamate for 90 min caused cell swelling and a significant increase in glycogen content. Conversely, treatment with hypertonic media caused cell shrinkage with a corresponding decrease in astrocyte glycogen, which was proportional to the increasing osmolality of the hypertonic media. The glutamate receptor antagonist, MK-801, lowered both the glutamate-induced swelling and glycogen increase. These findings demonstrate a correlation between changes in cell volume and astrocyte glycogen content. This may explain the increased astrocytic glycogen observed in many neuropathological conditions where astrocyte swelling occurs. Because glycogen represents the largest energy reserve in the central nervous system, a swelling-induced disturbance in glycogen metabolism may lead to abnormal glial-neuronal interactions resulting in impaired brain bioenergetics.
Dombro
R S
RS
Veterans Administration Medical Center, Miami, FL, USA.
Bender
A S
AS
Norenberg
M D
MD
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology*; D006003:Glycogen / Q000378:metabolism*; D007038:Hypotonic Solutions / Q000494:pharmacology*; D009994:Osmolar Concentration; D051381:Rats; D011916:Rats, Inbred F344; D014867:Water / Q000378:metabolism
D018691:Excitatory Amino Acid Antagonists; D007038:Hypotonic Solutions; D014867:Water; D018698:Glutamic Acid; D016291:Dizocilpine Maleate; D006003:Glycogen