The stimulating effect of piracetam on the respiration and glycolysis was observed in rat brain cortex slices incubated under oxygen atmosphere. After preincubation of the slices under pure nitrogen atmosphere, piracetam infuenced also decarboxylation of the C1-glucose carbon, indicating stimulation of the pentose cysle. Any significant effect of piracetam on the lowered by anoxia incorporation of 14C from U-14C-glucose into macromolecular fractions was not observed. The results have supported a protective effect of piracetam against oxygen deficiency, caused mainly by stimulation of metabolic glucose pathways, connected with energy production in CNS.