The effect of 5-hydroxytryptamine and histamine on glycolysis in the mouse brain.

Following the intraventricular injection of 5-hydroxytryptamine into the lateral ventricles of conscious mice, the concentration of brain lactate rose immediately but then decreased significantly compared with the saline injected controls. The concentration of brain glucose increased 20 min after the injection of 5-hydroxytryptamine. These effects of 5-hydroxytryptamine on lactate and glucose were qualitatively similar to those found following the administration of methysergide. After the parenteral administration of 5-hydroxytryptophan, the lactate levels showed a bephasic change but brain glucose was significantly decreased for up to 90 min following the injection. p-Chlorophenylalanine potentiated the effect of 5-hydroxytryptamine by further increasing glucose and decreasing lactate levels. After histamine had been injected into the ventricles, the concentrations of bound glycogen and lactate were decreased whereas free glycogen and glucose were raised. It is suggested that 5-hydroxytryptamine, and possibly histamine, are involved with control of glycolysis in the mouse brain.