GABAB receptor antagonists

Homotaurine, also known as tramiprosate (INN), 3-amino-1-propanesulfonic acid, or 3-APS, is a natural sulfonic acid found in seaweed. It is analogous to taurine, but with an extra carbon in its chain. It has GABAergic activity, apparently by mimicking GABA, which it resembles.

SCH-50911 is a selective GABAB antagonist. Its main applications are in pharmacology research.

Saclofen is a competitive antagonist for the GABAB receptor. This drug is an analogue of the GABAB agonist baclofen. The GABAB receptor is heptahelical receptor, expressed as an obligate heterodimer, which couples to the Gi/o class of heterotrimeric G-proteins. The action of saclofen on the central nervous system is understandably modest, because G-proteins rely on an enzyme cascade to alter cell behavior while ionotropic receptors immediately change the ionic permeability of the neuronal plasma membrane, thus changing its firing patterns. These particular receptors, presynaptically inhibit N-

Phaclofen, or phosphonobaclofen, is a selective antagonist for the GABAB receptor. It was the first selective GABAB antagonist discovered, but its utility was limited by the fact that it does not cross the blood brain barrier.