108498-50-6

IC50: 0.25 to 0.43 μM (Histamine H ₂ -receptor)

Positive chronotropic response to histamine at 10 ^-5 M is dose dependently inhibited by FRG8701 (FRG-8701) famotidine or cimetidine; and the IC ₅₀ values of FRG8701, famotidine and cimetidine are 3.3, 3.0 and 108.6 (×10 ^-7 M), respectively.The inhibitory potency of FRG8701 is almost the same as that of famotidine and approximately 33 times greater than that of cimetidine.

In the pylorus-ligated (4 hr) rats, each drug, given intraduodenally, dose-dependently inhibits the total acid output. FRG8701 at 10 or 30 mg/kg, given orally or intraperitoneally, significantly prevent the formation of the gastric mucosal lesions induced by 0.4 N HCI+50% ethanol (HCI•ethanol). Other necrotizing agents-induced gastric lesions are also inhibited by treatment of FRG8701. The oral ED ₅₀ values against the lesions range from 1.1 to 9.4 mg/kg. FRG8701, given orally, dose-dependently prevents the development of gastric lesions induced by stress and indomethacin. Duodenal ulcer induced by mepirizole is also inhibited with FRG8701. The ED ₅₀ values of FRG8701 for each ulcer model range from 1.7 to 6.9 mg/kg.