title: The difference in effect of predosing with antiallergic compounds between the rat PCA model and the monkey asthma model. Comparison of the effects of PRD-92-Ea and disodium cromoglycate.
abstract: DSCG and PRD-92-Ea showed tachyphylaxis in the rat PCA test when a large intravenous dose (40 mg/kg of DSCG and 20 mg/kg of PRD-92-Ea) was given 30 min before administering intravenously the expected effective doses at the time of antigen challenge. This predosing led to a marked loss of effectiveness. Cross-reacting tachyphylaxis was also demonstrated in this model. Predosing rats with DSCG led to a great loss of effectiveness of a subsequent expected active dose of PRD-92-Ea and predosing with PRD-92-Ea had the same effect in preventing the antiallergic action of a subsequent dose of DSCG. The Rhesus monkey (Macaca mulatta) did not exhibit this phenomenon of tachyphylaxis. PRD-92-Ea and DSCG were given intravenously 30 min before and the same dose of 20 mg/kg repeated just before Ascaris suum challenge in the Rhesus monkey asthma model with no loss of their expected effectiveness.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001249:Asthma / Q000276:immunology*; D001578:Benzopyrans / Q000008:administration & dosage / Q000494:pharmacology*; D004205:Cromolyn Sodium / Q000008:administration & dosage / Q000494:pharmacology*; D003429:Cross Reactions; D004195:Disease Models, Animal; D004306:Dose-Response Relationship, Immunologic; D000882:Haplorhini; D007275:Injections, Intravenous; D008253:Macaca mulatta; D008297:Male; D010323:Passive Cutaneous Anaphylaxis; D051381:Rats; D013618:Tachyphylaxis; D013997:Time Factors
chemical_list: D001578:Benzopyrans; D004205:Cromolyn Sodium