title: Effects of a newly synthesized leukotriene antagonist, NZ-107, on immediate-type hypersensitivity reaction in rats and guinea-pigs.
abstract: The effects of 4-bromo-5-(3-ethoxy-4-methoxybenzylamino)-3(2H)-pyridazinone (NZ-107) on immediate type hypersensitivity reactions in rats and guinea-pigs were studied. 1. When NZ-107, at a dose of 50 mg/kg (i.p.) or 100 mg/kg (orally), was administered to rats, 48-h homologous passive cutaneous anaphylaxis (PCA) reaction and histamine-, leukotriene C4 (LTC4)- and leukotriene D4 (LTD4)-induced skin reactions were suppressed by the agent. 2. NZ-107 (10(-6) g/ml) inhibited both LTC4- and LTD4-induced contractions of isolated rat stomach smooth muscle. 3. NZ-107 inhibited antigen-induced histamine release from rat peritoneal mast cells by 26% at a concentration of 10(-4) g/ml. 4. NZ-107, at doses of 25 and 50 mg/kg (orally), significantly inhibited guinea-pig 3-h heterologous PCA reaction. 5. NZ-107 inhibited antigen-induced histamine release from guinea-pig lung tissue by 17% and 48% at concentrations of 5 x 10(-5) and 10(-4) g/ml, respectively. 6. NZ-107, at doses of 25 and 50 mg/kg (i.p.), inhibited antigen-induced bronchoconstriction and eosinophil accumulation in the bronchoalveolar lavage fluid (BALF) of guinea-pigs. These results suggest that NZ-107 has anti-allergic action including inhibition of eosinophil accumulation in an antigen-challenged airway lesion in rats and guinea-pigs. The anti-allergic action of this agent is thought to be due to its action as a histamine and LT antagonist and its consequent inhibition of antigen-induced histamine release.
mesh_terms: D000818:Animals; D016084:Bronchoconstriction / Q000187:drug effects; D004802:Eosinophilia / Q000517:prevention & control; D005260:Female; D006168:Guinea Pigs; D006636:Histamine Release / Q000187:drug effects; D006969:Hypersensitivity, Immediate / Q000517:prevention & control*; D066298:In Vitro Techniques; D020024:Leukotriene Antagonists; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D010323:Passive Cutaneous Anaphylaxis / Q000187:drug effects; D011724:Pyridazines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D020024:Leukotriene Antagonists; D011724:Pyridazines; C062698:NZ 107