Antiallergic properties of SQ 13,847, an orally effective agent. I. Activity in vivo.
A structurally novel pyrazolo[1,5-c]quinazoline, SQ 13,847, was demonstrated to be an orally active antiallergic agent. The compound inhibited immunoglobulin (Ig)E-mediated passive cutaneous anaphylaxis (PCA) and passive pulmonary anaphylaxis in the rat (ID50 = 2 to 4 mg/kg p.o.), but failed to affect IgG-mediated PCA in the rat, IgE-mediated PCA in the mouse or IgG1-mediated PCA in the guinea pig. The relative potencies of SQ 13,847 and its 2-carboxylic acid metabolite, SQ 12,903, upon oral vs. intravenous administration were consistent with a role of SQ 13,847 as an orally absorbed prodrug of SQ 12,903. In the rat, SQ 13,847 is not an antagonist of histamine in serotonin, in beta adrenergic agonist or a bronchodilator.
D000818:Animals; D001986:Bronchial Spasm / Q000188:drug therapy*; D005260:Female; D006168:Guinea Pigs; D006967:Hypersensitivity / Q000188:drug therapy*; D008168:Lung / Q000187:drug effects; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D010323:Passive Cutaneous Anaphylaxis / Q000187:drug effects*; D011799:Quinazolines / Q000494:pharmacology*; D051381:Rats; D013045:Species Specificity
D011799:Quinazolines; C028173:pirquinozol