Noradrenaline (norepinephrine) inactivation

The Diffusion and reuptake are the key mechanisms eliminating NA from the synapse. The noradrenaline (norepinephrine) transporter is a saturable Na⁺/Cl^--dependent transporter expressed in noradrenergic neurons. It distributes homology with the dopamine transporter. The noradrenaline (norepinephrine) transporter is reserved by the tricyclic antidepressant group of drugs.

The metabolic degradation of NA is not significant for its inactivation and takes place through different routes in the periphery and CNS. In CNS, the monoamine oxidase (MAO) catalyzes the creation of 3,4-dihydroxy phenylglycoaldehyde that is then decreased to the corresponding alcohol, 3,4-dihydroxy phenylglycol (DOPEG). Lastly this is methylated by COMT to give 3-methoxy,4-hydroxy phenylglycol (MOPEG) that is excreted in the urine.