LY310762 is a 5-HT1D receptor antagonist with Ki of 249 nM, having a weaker affinity for 5-HT1B receptor.IC50 value: 249 nM (Ki) [1]Target: 5-HT1D in vitro: LY310762 has a higher affinity for the guinea pig 5-HT1D receptor than for the 5-HT1B receptor. LY310762 potentiates the potassium-induced [3H]5-HT outflow from guinea pig cortical slices with an EC50 of 30 nM. The maximum potentiation of the potassium-induced outflow which is obtained with LY310762 is about 40% [1]. LY310762 blocks the decreased EPSC amplitude induced by Sumatriptan [2]. in vivo: Systemic administration of LY310762 (10 mg/kg i.p.) produces a further significant enhancement in the 5-HT response to fluoxetine (20 mg/kg i.p.) when compared to animals receiving a control vehicle injection. In fluoxetine treated animals, levels of 5-HT increases from 312±43% to a maximum of 683% after LY310762. In control animals, levels of 5-HT remains unchanged (250%). LY310762 administered alone also significantly increases basal levels of 5-HT above vehicle controls, reaching a maximum of 258% compared to the pre-injection control [1].

References:
[1]. Pullar IA, et al. The role of the 5-HT1D receptor as a presynaptic autoreceptor in the guinea pig. Eur J Pharmacol, 2004, 493(1-3), 85-93.
[2]. Choi IS, et al. 5-HT(1B) receptors inhibit glutamate release from primary afferent terminals in rat medullary dorsal horn neurons. Br J Pharmacol, 2012,167(2), 356-367.