Protective effect of piracetam against PGF2 alpha-impaired cerebral resistance to hypoxia

The protective effect of piracetam against PGF2 alpha-impaired cerebral resistance to hypoxia was investigated by EEG study in relaxed and artificially ventilated cats. Asphyxic anoxia was performed after 5 min of intracarotid (i.c.) or i.v. infusion of 10 micrograms/kg/min PGF2 alpha before and 30 min after piracetam (100 mg/kg i.v.). The following parameters were determined: cortical resistance (CRs)--as time between stopping the ventilation and the extinction of EEG; cortical recovery (CRc) - as time between restitution of ventilation and reappearance of brain activity; anoxia resistance index (ARI) - as the ratio between these two parameters (CRs/Crc). Both the i.c. and i.v. infusion of PGF2 alpha led to a significant decrease in CRs and lengthening of CRc which resulted in a decrease in ARI. Piracetam reverses the PGF2 alpha-induced changes in asphyxic anoxia. The possible mechanism of piracetam's effect and the probable therapeutic value of the latter are considered.