Nerve growth factor increases in adult rat brain after hypoxic injury

Brain injury increases the synthesis of many growth and trophic factors. We have measured nerve growth factor (NGF) content in brain of adult rats with bilateral carotid artery occlusion exposed to 7% O2. Five days after hypoxia the NGF content was increased in neostriatum, hippocampus and cerebral neocortex, areas exhibiting focal neuronal degeneration and inflammation. The increase was not related to changes in choline acetyltransferase activity that was only reduced in heavily damaged cortex. The findings may indicate that the increase in NGF content was due to enhanced NGF synthesis by inflammatory cells including stimulated glia.