Swelling-Induced Release of Glutamate, Aspartate, and Taurine from Astrocyte Cultures
The Journal of Neuroscience, May 1990, IO@): 1583-l 591 Swelling-Induced Release of Glutamate, Aspartate, and Taurine from Astrocyte Cultures H. K. Kimelberg,1,2,3 S. K. Goderie,’ S. Higman,’ S. Pang,laa and R. A. Waniewski4 ‘Division of Neurosurgery, *Department of PharmacologyiToxicology, 9nterdepartmental Program in Neuroscience, Albany Medical College, Albany, New York 12208, and 4Wadsworth Center for Laboratories and Research, New York State Department 07 Health, Albany, New York 12201 Swelling of primary astrocyte cultures by exposing them to astrocytes seenin a number of pathological states (Kimelberg hypotonic media caused release of label after the cells had and Ransom, 1986), since swelling of isolated cells and many been allowed to accumulate 3H-L-glutamate, 3H-D-aSpattate, vertebrate and invertebrate tissuesis known to lead to the release or 3H-taurine. Comparable release of endogenous L-gluta- of taurine, glutamate, aspartate, and other amino acids as part mate or taurine, as measured by high-pressure liquid chro- of the processof regulatory volume decrease(RVD) by which matography (HPLC), was also found. Release of label was swollen cells regain their normal volume (Gilles et al., 1987). not affected by treating the cells with cytochalasin B, indi- The pathological conditions in which astroglial swelling is cating that microfilament polymerization was not signifi- observed include experimental (Barron et al., 1988) and human cantly involved. Hypotonic-induced release did not appear (Castejon, 1980) closed head injury, traumatic (stab wound) to principally involve reversal of the Na+-dependent uptake brain edema(Gerschenfeld et al., 1959), ischemia (Garcia et al., system since increasing external K+ to depolarize the cells 1977; Jenkins et al., 1984) hypoglycemia and status epilepticus by replacement of external Na+, thus maintaining isotonic (Siesjo, 1981) prolonged hypoxia (Yu et al., 1972), acute hy- conditions, increased release to a lesser extent.
[Show full text]