CGP is a potent, selectie GABAB receptor antagonist.
Potent, selective GABA B receptor antagonist (IC 50 = 5 nM) that prevents agonist binding (pK i = 8.35) and inhibits GABA and glutamate release (pEC 50 values are 8.08 and 7.85 respectively). Inhibits GABA B responses to baclofen (IC 50 = 130 nM in an isoproterenol assay) and potentiates the hypoglycemic response to glucose in vitro .
CGP 55845 is a potent selective GABA-B receptor antagonist with an IC50 of 5 nM.
antagonist cgp 55845a of the gabab receptor in the presence of cnqx and d(2)-2-amino-5-phosphonovaleric acid prevented the inhibitory postsynaptic potential-b and paired-pulse depression. [3].
[1] waldmeier pc, wicki p, feldtrauer jj, mickel sj, bittiger h, baumann pa. gaba and glutamate release affected by gabab receptor antagonists with similar potency: no evidence for pharmacologically different presynaptic receptors. br j pharmacol. 1994 dec;113(4):1515-21.
[2] cunningham md, enna sj. evidence for pharmacologically distinct gabab receptors associated with camp production in rat brain. brain res. 1996 may 13;720(1-2):220-4.
[3] deisz ra. the gaba(b) receptor antagonist cgp 55845a reduces presynaptic gaba(b) actions in neocortical neurons of the rat in vitro. neuroscience. 1999;93(4):1241-9.
[4] zhang m, buttigieg j, nurse ca. neurotransmitter mechanisms mediating low-glucose signalling in cocultures and fresh tissue slices of rat carotid body. j physiol. 2007 feb 1;578(pt 3):735-50. epub 2006 nov 23.
[5] salah a, perkins kl. effects of subtype-selective group i mglur antagonists on synchronous activity induced by 4-aminopyridine/cgp 55845 in adult guinea pig hippocampal slices. neuropharmacology. 2008 jul;55(1):47-54. doi: 10.1016/j.neuropharm.2008.04.010. epub 2008 apr 23.
