Glycine

Glycine, a major inhibitory transmitter in the CNS (predominantly in the spinal cord and brainstem), is only slightly increased in whole rat brain at high concentrations of a volatile agent.^[67] It seems unlikely that glycine plays a major role in the production of the anesthetic state because massive intravascular infusions of glycine that are occasionally seen as a complication of urologic surgery with the use of a glycine irrigation solution ( Chapter 54 ) do not produce general anesthesia. Nevertheless, the ability of a specific glycine receptor antagonist (e.g., strychnine) to increase the isoflurane MAC implies a partial involvement of glycine receptors in the production of immobility by volatile anesthetics.^[71]