title: Methacholine-induced pulmonary gas trapping in guinea pigs, hamsters, mice, and rats.
abstract: Postmortem pulmonary gas trapping was investigated as an index of in vivo airway obstruction following methacholine inhalation in four different rodent species. Male guinea pigs (Hartley), hamsters (golden Syrian), mice (A/J, BALB/c, and ICR), and rats (Brown-Norway, Fischer 344, Lewis, and Sprague-Dawley) were exposed to aerosols of methacholine or sodium chloride. Maximum excised lung gas volumes (ELGV) of methacholine-exposed guinea pigs, hamsters, mice, and rats were 2.3-8.7 times those of sodium chloride-treated animals. Mean ELGV values of sodium chloride-exposed animals ranged from 1.50 +/- 0.20 ml/kg for guinea pigs to 2.75 +/- 0.20 ml/kg for Brown-Norway rats. Although all species responded to methacholine, guinea pigs were the most responsive, with approximately 1.6 microgram/kg of inhaled methacholine needed to increase ELGV to 200% of control. Compared with guinea pigs, hamsters, mice, and rats were 11- to 1,395-fold less responsive. Although hamsters, mice, and rats are less sensitive than guinea pigs to the airway-obstructive effects of methacholine, pulmonary gas trapping appears useful as a measure of airway responses in these species.
authors.affiliation: Cardiovascular Research, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Stengel
authors.forename: C A
authors.initials: CA
authors.lastname: Yiamouyiannis
authors.forename: R L
authors.initials: RL
authors.lastname: Obenchain
authors.forename: S L
authors.initials: SL
authors.lastname: Cockerham
authors.forename: S A
authors.initials: SA
authors.lastname: Silbaugh
mesh_terms: D000818:Animals; D016084:Bronchoconstriction / Q000502:physiology; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D008168:Lung / Q000187:drug effects / Q000502:physiology; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology*; D051379:Mice; D011659:Pulmonary Gas Exchange / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley
chemical_list: D016210:Methacholine Chloride