title: Role of leukotriene D4 in the early and late pulmonary responses of rats to allergen challenge.
abstract: To examine the role of leukotriene D4 (LTD4) in early and late pulmonary responses to antigen, we evaluated the effects of two LTD4, antagonists, MK-571 and FPL-57231, on the changes in pulmonary resistance (RL) in the 8-h period following antigen challenge of allergic rats. A total of 69 rats, aged 6 to 8 wk, were sensitized to subcutaneous ovalbumin (OA, 1 mg) and intraperitoneal Bordetella pertussis vaccine (6 x 10(9) bacilli). At 14 days after sensitization, rats were anesthetized with intraperitoneal urethane (1.1 g/kg) and intubated endotracheally. Aerosols of OA (5% wt/vol in saline for 5 min) were administered to 24 control rats, to 11 rats that were pretreated with aerosolized FPL-57231, and to 8 rats that were pretreated with MK-571; 6 rats also received MK-571 at 2 h after OA. A control group of 13 rats was challenged with aerosols of saline. We defined an early response (ER) as an increase in RL to at least 150% of the postsaline value occurring within 1 h after OA challenge. A late response (LR) was defined as a value of RL exceeding the mean plus 2 SD of all values of RL from 75 min to 8 h after OA challenge and lasting at least 30 min. An ER was observed in 17 of 24 control rats, in 8 of 11 FPL-57231-pretreated rats, and in 3 of 8 MK-571-pretreated rats (not significant). The magnitude and duration of the ER were significantly reduced by MK-571, whereas only the duration was affected by FPL-57231.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Meakins-Christie Laboratories, McGill University, Montreal Quebec, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Sapienza
authors.forename: D H
authors.initials: DH
authors.lastname: Eidelman
authors.forename: P M
authors.initials: PM
authors.lastname: Renzi
authors.forename: J G
authors.initials: JG
authors.lastname: Martin
mesh_terms: D000485:Allergens; D000818:Animals; D001985:Bronchial Provocation Tests; D001986:Bronchial Spasm / Q000209:etiology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002867:Chromones; D005260:Female; D007114:Immunization; D008297:Male; D011422:Propionates; D011804:Quinolines; D051381:Rats; D011914:Rats, Inbred BN; D013189:SRS-A / Q000037:antagonists & inhibitors / Q000502:physiology*; D013997:Time Factors
chemical_list: D000485:Allergens; D002867:Chromones; D011422:Propionates; D011804:Quinolines; D013189:SRS-A; C059141:verlukast; C034338:FPL 57231