L-365260 hemihydrate

L-365260 hemihydrate is an orally active and selective antagonist of non-peptide gastrin and brain cholecystokinin receptor (CCK-B), with Kis of 1.9 nM and 2.0 nM, respectively. L-365260 hemihydrate interacts in a stereoselective and competitive manner with guinea pig stomach gastrin and brain CCK receptors.

L-365260 hemihydrate exhibits a similar high affinity for brain CCK-B receptors of rats, mice and man, and a lower affinity for gastrin and brain CCK-B (IC₅₀=20-40 nM) receptors in dog tissues^[1].
L-365260 (1 μM) hemihydrate strongly attenuates the CCK8S- and CCK4-mediated depolarization in a different neuron^[2].

L-365260 hemihydrate (0.1-30 mg/kg; p.o.) antagonizes gastrin-stimulated acid secretion in mice (ED₅₀=0.03 mg/kg), rats (ED₅₀=0.9 mg/kg) and guinea pigs (ED₅₀=5.1 mg/kg)^[1].
L-365260 hemihydrate (0.01-10 mg/kg; s.c.) enhances analgesia induced by a submaximal dose of Morphine (4 mg/kg) in rats^[3].
L-365260 hemihydrate (0.2 mg/kg; s.c. twice daily for 5 days) significantly prolongs the duration of Morphine analgesia in rats^[3].

References:
[1]. Lotti VJ, et, al. A new potent and selective non-peptide gastrin antagonist and brain cholecystokinin receptor (CCK-B) ligand: L-365,260. Eur J Pharmacol. 1989 Mar 21;162(2):273-80.
[2]. Dourish CT, et, al. The selective CCK-B receptor antagonist L-365,260 enhances morphine analgesia and prevents morphine tolerance in the rat. Eur J Pharmacol. 1990 Jan 25;176(1):35-44.
[3]. Lotti VJ, et, al. A new potent and selective non-peptide gastrin antagonist and brain cholecystokinin receptor (CCK-B) ligand: L-365,260. Eur J Pharmacol. 1989 Mar 21;162(2):273-80.