Study objectives: To study the effects of extracts of brewery dust on isola
ted guinea pig trachea smooth muscle in vitro.
Design: Parallel pharmacologic intervention on guinea pig tracheal rings th
at were obtained from the same animal.
Setting: Mount Sinai School of Medicine, Department of Pulmonary Medicine.
Material: The isolated guinea pig tracheal tissue of 18 guinea pigs.
Interventions: Pretreatment of guinea pig rings by mediator-modifying agent
s before challenge with the brewery dust extracts.
Measurements and results: The effect of brewery dust extracts on isolated g
uinea pig tracheal smooth muscle was studied using water-soluble extracts o
f dust obtained from brewery materials, including hops, barley, and brewery
yeast. Dust extracts were prepared as a 1:10 (wt/vol) aqueous solution. Do
se-related contractions of nonsensitized guinea pig tracheas were demonstra
ted using these extracts. The dust extracts contained significant quantitie
s of bacterial components leg, endotoxin and n-formyl-methionyl-leucyl-phen
ylalanine), but these agents were not thought to contribute directly to the
constrictor effect of the dusts. Pharmacologic studies were performed by p
retreating guinea pig tracheal tissue with the following drugs known to mod
ulate smooth muscle contraction: atropine; indomethacin; pyrilamine; LY1718
83; nordihydroguaiaretic acid; captopril; thiorphan; verapamil; and TMB8. T
he constrictor effects of the dust extracts were inhibited by a wide variet
y of agents, the patterns of which depended on the dust extract, Atropine c
onsistently and strikingly reduced the contractile effects of these extract
s. These observations may suggest an interaction of the extracts with paras
ympathetic nerves or, more directly, with muscarinic receptors, The inhibit
ion of contraction by the blocking of other mediators was less effective an
d varied with the dust extract.
Conclusions: We suggest that brewery dust extracts cause a dose-related air
way smooth muscle constriction by nonimmunologic mechanisms involving a var
iety of airway mediators and, possibly, cholinergic receptors, This effect
is not dependent on presensitization of the guinea pigs,