Effects of Glutamate on Glycerophospholipid Degradation

5 Excitatory Amino Acid Receptors and Neural Membrane 

6-cyano-7-nitroquinoxaline (CNQX) block this release in a dose-dependent manner (Table 5.2). As pH shifts from 7.2 to 7.8, the glutamate-mediated release of arachi-donic acid is enhanced 3-fold (Stella et al., 1995). Quinacrine, a CPLA2 non-specific inhibitor (Sanfeliu et al., 1990 Kim et al., 1995 Farooqui et al., 2003b), as well as arachidonoyl trifluoromethylketone, a potent inhibitor of CPLA2, also inhibit this increase in CPLA2 activity mediated by glutamate (Table 5.3). 

Systemic administration of KA into adult rats markedly increases CPLA2 immunoreactivity in neurons at 1 and 3 days after injection (Sandhya et al., 1998). KA injection increases the CPLA2 immunoreactivity in astrocytes after 1, 2, 4, 11 weeks. Increased CPLA2 activity in neurons in KA-mediated toxicity may be involved in neurodegeneration, whereas the elevation of CPLA2 immunoreactivity in astrocytes is associated with gliosis (Sandhya et al., 1998 Farooqui et al., 1997c) 

CPLA2 activity was determined by procedure described earlier. Results are the means SEM for three different cultures. APV, 2-amino-5- phosphonovalerate and CNQX, 6-cyano-7-nitroquinox aline. 

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