FRG8701 is a new Histamine H2-receptor antagonist with an IC50 of ranging from 0.25 to 0.43 μM.

H2 receptor:0.25 to 0.43 μM

The inhibitory potency of FRG8701 is almost the same as that of famotidine and approximately 33 times greater than that of cimetidine.Positive chronotropic response to histamine at 10-5 M is dose dependently inhibited by FRG8701 (FRG-8701) famotidine or cimetidine;?and the IC50 values of FRG8701, famotidine and cimetidine are 3.3, 3.0 and 108.6 (×10-7M), respectively.

FRG8701 effectively inhibits the formation of gastric lesions induced by various necrotizing agents, demonstrating its protective effects on the gastrointestinal tract. Oral administration of FRG8701 produces a dose-dependent reduction in the development of gastric lesions caused by stress, indomethacin, and the formation of duodenal ulcers due to mepirizole, with ED50 values ranging from 1.1 to 9.4 mg/kg for gastric lesions and 1.7 to 6.9 mg/kg for each ulcer model. Additionally, in pylorus-ligated rats, intraduodenal delivery of FRG8701 dose-dependently decreases total acid output. Furthermore, FRG8701, whether administered orally or intraperitoneally at doses of 10 or 30 mg/kg, significantly prevents gastric mucosal lesions induced by 0.4 N HCl+50% ethanol, underscoring its potential as a protective agent against gastrointestinal damage.