Water and electrolyte contents, cell pH, and membrane potential of primary cultures of astrocytes from DBA, C57, and SW mice.

Some basic properties of primary cultures of astrocytes derived from the cerebral cortex of an audiogenic seizure-sensitive strain of mice, DBA/2J (DBA), were studied with different approaches. The results were compared with those of audiogenic seizure-resistant strains, C57BL/6J (C57) and Swiss Webster (SW). Contents of intracellular water, protein, and DNA of DBA astrocytes were 0.673 +/- 0.019 ml/g cells, 0.082 +/- 0.006 g/g cells, and 0.0072 +/- 0.0005 g/g cells, respectively. These results are not different from those of either C57 or SW astrocytes. Intracellular concentration of K+, Na+, and Cl- ([K+]1, [Na+]1, and [Cl-]1) derived from the flame photometric and from the radioisotope uptake data of DBA astrocytes were 120.4 +/- 8.5, 25.9 +/- 3.2, and 26.8 +/- 1.8 mM/L cell H2O, respectively. [Na+]1 and [Cl-]1 in DBA astrocytes were lower than those in C57 and SW astrocytes. In DBA astrocytes, SITS decreased the cell/medium ratio (C/M) of 36Cl- and increased the C/M of 125I-; ouabain increased the C/M of 22Na+ and decreased the C/M of 125I-; bumetanide decreased the C/M of both 36Cl- and 22Na+; and NaClO4 decreased the C/M of 125I-. Similar results were observed in both C57 and SW astrocytes. Intracellular pH (pHi) as determined with 14C-DMO of astrocytes in HEPES-buffered saline solution averaged 7.04 +/- 0.03 for DBA, 7.01 +/- 0.02 for C57, and 6.97 +/- 0.02 for SW mice when pH of medium was maintained at 7.4. Modification of ion (HCO3-, Cl-, Na+, and K+) concentration and pH of culture medium all changed the pHi of astrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)