Grapiprant
In vitro,
Grapiprant inhibits [(3)H]PGE(2) binding to both human and rat EP(4) receptors with K(i) of 13 +/- 4 and 20 +/- 1 nM, respectively. Grapiprant is highly selective for the human EP(4) receptor over other human prostanoid receptor subtypes. Grapiprant also inhibits PGE(2)-evoked elevation in intracellular cAMP at the human and rat EP(4) receptors with pA(2) of 8.3 +/- 0.03 and 8.2 +/- 0.2 nM, respectively.
In vivo, oral administration of Grapiprant significantly reduces thermal hyperalgesia induced by intraplantar injection of PGE(2) (ED(50) = 12.8 mg/kg).
For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the Km factor for a mouse and then divide by the Km factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.
Detection and quantification of the selective EP4 receptor antagonist CJ-023423 (grapiprant) in canine plasma by HPLC with spectrofluorimetric detection.
Vito V, et al. J Pharm Biomed Anal. 2016 Jan 25;118:251-258. PMID: 26580822.
Evaluation of the safety of long-term, daily oral administration of grapiprant, a novel drug for treatment of osteoarthritic pain and inflammation, in healthy dogs.
Rausch-Derra LC, et al. Am J Vet Res. 2015 Oct;76(10):853-9. PMID: 26413822.
Effects of the selective EP4 antagonist, CJ-023,423 on chronic inflammation and bone destruction in rat adjuvant-induced arthritis.
Okumura T, et al. J Pharm Pharmacol. 2008 Jun;60(6):723-30. PMID: 18498708.
