The effects of audiogenic stress (92 dB at 2000 Hz) on the liver and adrenal levels of glucose-6-phosphate-dehydrogenase (G6-PD) and 6-phosphogluconate-dehydrogenase (6-PGD) were studied in adult male rats. Blood glucose and liver glycogen were also measured. In liver of stressed rats the levels of glycogen, G6-PD and 6-PGD were lower in comparison with controls. On the contrary, a significant increase of the measured enzymatic activities was shown in the adrenals. The mechanism and biological meaning of such modifications are discussed.