Open AccessThe Pharmacology of DMP696 and DMP904, Non‐Peptidergic CRF 1 Receptor Antagonists
Author(s) -
Li YuWen,
Fitzgerald Lawrence,
Wong Harvey,
Lelas Snjezana,
Zhang Ge,
Lindner Mark D.,
Wallace Tanya,
McElroy John,
Lodge Nicholas J.,
Gilligan Paul,
Zaczek Robert
Publication year - 2005
Publication title -
cns drug reviews
Language(s) - English
Resource type - Journals
eISSN - 1527-3458
pISSN - 1080-563X
DOI - 10.1111/j.1527-3458.2005.tb00034.x
Subject(s) - anxiolytic , pharmacology , receptor , adenylyl cyclase , chemistry , in vivo , elevated plus maze , chlordiazepoxide , endocrinology , medicine , anxiety , biology , diazepam , microbiology and biotechnology , psychiatry
ABSTRACT CRF 1 antagonists DMP696 and DMP904 were designed as drug development candidates for the treatment of anxiety and depression. Both compounds display nanomolar affinity for human CRF 1 receptors, and exhibit >1000‐fold selectivity for CRF 1 over CRF 2 receptors and over a broad panel of other proteins. DMP696 and DMP904 block CRF‐stimulated adenylyl cyclase activity in cortical homogenates and cell‐lines expressing CRF 1 receptors. Both compounds inhibit CRF‐stimulated ACTH release from rat pituitary corticotropes. Binding and functional studies indicate that DMP696 and DMP904 behave as noncompetitive full antagonists. DMP696 and DMP904 exhibit anxiolytic‐like efficacy in several rat anxiety models. In the defensive withdrawal test, both compounds reduce exit latency with lowest effective doses of 3 and 1 mg/kg, respectively. The anxiolytic‐like effect is maintained over 14 days of repeated dosing. In the context of a novel environment used in this test, DMP696 and DMP904 reverse mild stress‐induced increases in plasma CORT secretion but at doses 3‐4‐fold greater than those required for anxiolytic‐like efficacy. DMP696 and DMP904 are ineffective in three depression models including the learned helplessness paradigm at doses up to 30 mg/kg. At lowest anxiolytic‐like doses, DMP696 and DMP904 occupy >50% CRF 1 receptors in the brain. The in vivo IC 50 values (plasma concentrations required for occupying 50% CRF 1 receptors) estimated based upon free, but not total, plasma concentrations are an excellent correlation with the in vitro IC 50 values. Neither compound produces sedation, ataxia, chlordiazepoxide‐like subjective effects or adverse effects on cognition at doses 10‐fold higher than anxiolytic‐like doses. Neither compound produces physiologically significant changes in cardiovascular, respiratory, gastrointestinal or renal functions at anxiolytic‐like doses. DMP696 and DMP904 have favorable pharmacokinetic profiles with good oral bioavailabilities. The overall pharmacological properties suggest that both compounds may be effective anxiolytics with low behavioral side effect liabilities.