Anti-allergic properties of ethyl-3-methoxyphenyl-4-thiazolyl-2-oxamate (F 1865)

F 1865 (ethyl-3-methoxyphenyl-4-thiazolyl-2-oxamate) has powerful oral anti-allergic properties in immediate hypersensitivity models in rats. In IgE-dependent passive cutaneous anaphylaxis (PCA) the ED50 was of 0.8 mg/kg. In IgG-dependent PCA the ED50 was of 0.6 mg/kg. This oxamate derivative inhibited the liberation of histamine during passive peritoneal anaphylaxis in rats at concentrations of 1 X 10(-6) M or higher. Doses of F 1865, active in PCA, had only weak anti-histamine and anti-serotonin effects, as measured by the increase of cutaneous capillary permeability. Likewise, its inhibitory effect on the bronchospasm due to histamine or serotonin in guinea-pigs was apparent only at doses of 1 mg/kg on i.v. administration. At doses of 100 mg/kg (X2) p.o., F 1865 was inactive against reverse passive Arthus pleurisy induced in rats by rabbit anti-bovine-albumin serum.