Glutamine and epilepsy

Abstract

The amount of glutamine is abundant in the central nervous system (CNS) and it is evenly distributed in the different brain regions [1, 2]. The transport of glutamine from blood to the brain is insufficient to reach the requirement of the brain, and the synthesis from glutamate by glutamine synthetase (GS) in astrocytes supplements the demand [2]. Glutamine is required for several physiological processes, including synthesis of proteins, osmoregulation and synthesis of glutamate and GABA [3]. So, glutamine is crucial to the glutamine-glutamate-GABA cycle in the brain, which may largely affect the balance between the excitatory and inhibitory transmission. However, the excessive accumulation of glutamine in the brain may result in CNS dysfunction, due to cerebral edema and mitochondrial damage. For instance, hyperammonemia can cause such disturbance by facilitating the formation of glutamine. Yet, this chapter focuses on the participation of glutamine in the glutamine-glutamate-GABA cycle, and the association between the disruption of the cycle and seizure or epilepsy.