ABSTRACT
We have previously demonstrated that the prototypical GABA B receptor agonist baclofen inhibits transient lower esophageal sphincter relaxations (TLESRs), the most important mechanism for gastroesophageal reflux. Thus, GABA B agonists could be exploited for the treatment of gastroesophageal reflux disease. However, baclofen, which is used as an antispastic agent, and other previously known GABA B agonists can produce CNS side effects such as sedation, dizziness, nausea, and vomiting at higher doses. We now report the discovery of atypical GABA B agonists devoid of classical GABA B agonist related CNS side effects at therapeutic doses and the optimization of this type of compound for inhibition of TLESRs, which has resulted in a candidate drug ( R)- 7 (AZD3355) that is presently being evaluated in man.
Subject(s)
GABA Agonists/chemistry , GABA Agonists/pharmacology , GABA-B Receptor Agonists , Gastroesophageal Reflux/drug therapy , Animals , Dose-Response Relationship, Drug , GABA Agonists/therapeutic use , Humans , Magnetic Resonance Spectroscopy , Spectrometry, Mass, Fast Atom BombardmentABSTRACT
The CRF antagonist pharmacophore is a heterocyclic ring bearing a critical hydrogen-bond acceptor nitrogen and an orthogonal aromatic ring. CRFR1 antagonists have shown a 40-fold and 200-fold loss in potency against the CRFR1 H199V and M276I mutant receptors, suggesting key interactions with these residues. We have derived a two component computational model that correlates CRFR1 binding affinity within the reported series to antagoinst/H199 complexation energy and M276 hydrophobic contacts.
