GR 125743 is a selective 5-HT1B/1D receptor antagonist, with pKis of 8.85 and 8.31 for wild-type h5-HT1B and wild-type h5-HT1D, respectively. GR 125743 is used for the research of Parkinson's disease and cardiovascular diseases[1][2].
GR 125743 has a Kd of 0.61 nM for h5-HT1B[1].
GR 125743 (0.3 mg/kg; i.p.) produces significant decreases in extracellular 5-HT in the frontal cortex of the conscious guinea pig[2]. Animal Model: Male Dunkin Hartley guinea-pigs (350-450 g)[2]
[1]. T Wurch, et al. Induction of a high-affinity ketanserin binding site at the 5-Hydroxytryptamine(1B) receptor by modification of its carboxy-terminal intracellular portion. Characterization of human serotonin 1D and 1B receptors using [3H]-GR-125743, a novel radiolabelled serotonin 5HT1D/1B receptor antagonist. Biochem Pharmacol. 2000 May 1;59(9):1117-21. [2]. Roberts, C., et al. The role of 5-HT1B/1D receptors in the modulation of 5-hydroxytryptamine levels in the frontal cortex of the conscious guinea pig. European Journal of Pharmacology. 1997 May 12;326(1):23-30.