Dexmedetomidine-induced stimulation of glutamine oxidation in astrocytes: A possible mechanism for its neuroprotective activity

Dexmedetomidine is a highly specific alpha(2)-adrenergic agonist, which is used clinically as an anesthetic adjuvant and in animal experiments has a neuroprotective effect during ischemia. The current study showed that dexmedetomidine enhances glutamine disposal by oxidative metabolism in astrocytes. This effect occurs at pharmacologically relevant concentrations. It is exerted on alpha(2)-adrenergic receptors and not on imidazoline-preferring sites, and it is large enough to reduce the availability of glutamine as a precursor of neurotoxic glutamate.