Effect of glutamate and its antagonist on shift of water from extra- to intracellular space after cerebral ischaemia.

The effects of glutamate and the excitatory amino acid antagonist, MK-801, were investigated on the time course of the shift of water from extracellular to intracellular space (progression or cytotoxic oedema) after total brain ischaemia in rats. Administration of sodium glutamate intravenously before ischaemia accelerated the shift of water dose-dependently. On the contrary, preischaemic administration of MK-801, an NMDA antagonist, delayed the progression of cytotoxic oedema due to brain ischaemia. We consider that glutamate and NMDA antagonists may have important roles in the development and prevention of cytotoxic oedema in the ischaemic state.