CGP 35348 is a selective antagonist of γ-aminobutyric acidB (GABAB) receptor with IC50 value of 34 μM [1].
The GABAB receptor is a metabotropic transmembrane receptors for GABA that is linked via G-protein to potassium channel. It stimulates the opening of K+ channel and hyperpolarize the neuron.
CGP 35348 is a selective GABAB receptor antagonist that can penetrate the blood-brain barrier. In rat cortex slices, CGP 35348 inhibited the potentiating effect of L-baclofen on adenylate cyclase stimulated by noradrenaline. In the hippocampal slice, CGP 35348 (10, 30, 100 μM) inhibited membrane hyperpolarization induced by L-baclofen (10 μM) and the inhibitory postsynaptic potential [1].
In the spinal cord of the rat, CGP 35348 (3-30 μg) inhibited L-baclofen-induced antinociception in a dose-dependent way [2]. In the rat, CGP 35348 induced pain-like response to mechanical stimulation in a dose-dependent way and reduced the paw withdrawal threshold to pressure [3]. In rats, CGP 35348(500 mg/kg) significantly reduced food consumption by the blockade of central GABAB receptors [4].
References:
[1]. Olpe HR, Karlsson G, Pozza MF, et al. CGP 35348: a centrally active blocker of GABAB receptors. Eur J Pharmacol, 1990, 187(1): 27-38.
[2]. Hammond DL, Washington JD. Antagonism of L-baclofen-induced antinociception by CGP 35348 in the spinal cord of the rat. Eur J Pharmacol, 1993, 234(2-3): 255-262.
[3]. Hao JX, Xu XJ, Wiesenfeld-Hallin Z. Intrathecal gamma-aminobutyric acidB (GABAB) receptor antagonist CGP 35348 induces hypersensitivity to mechanical stimuli in the rat. Neurosci Lett, 1994, 182(2): 299-302.
[4]. Patel SM, Ebenezer IS. The effects of intraperitoneal and intracerebroventricular administration of the GABAB receptor antagonist CGP 35348 on food intake in rats. Eur J Pharmacol, 2004, 503(1-3): 89-93.