Osmolyte contents of cultured astrocytes grown in hypoosmotic medium.
Primary rat cerebral astrocyte cultures were grown for 2 weeks in isoosmotic medium (305 mosmol) and then placed in similar medium with a reduced NaCl concentration. During the first hour of growth in this moderately hypoosmotic medium (240 mosmol), the cells lose 88% of their taurine contents, 62% of their alanine contents, and 54% of their aspartate contents while regaining normal volume. Loss of these amino acids accounts for 43% of observed volume regulation. Contents of these amino acids remain decreased during 24 h of growth in hypoosmotic medium. In contrast, potassium, glutamate, glutamine, and asparagine contents are not changed, relative to cells in isoosmotic medium, at time points between 1 h and 24 h of hypoosmotic exposure. The data suggest astrocytes contribute to net loss of amino acids, but not potassium, from brains exposed to hypoosmotic conditions in situ.
Olson
J E
JE
Department of Emergency Medicine, Wright State University School of Medicine, Cox Institute, Kettering, OH 45429, USA. jolson@nova.wright.edu
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001253:Astrocytes / Q000737:chemistry*; D001923:Brain Chemistry; D048429:Cell Size; D003470:Culture Media / Q000737:chemistry; D009994:Osmolar Concentration; D051381:Rats; D012965:Sodium Chloride / Q000032:analysis; D013402:Sugar Alcohols / Q000032:analysis; D013997:Time Factors