89841
document
Effect of inhaled heparin on adenosine-induced bronchial hyperreactivity . Glycosaminoglycan heparin possesses multiple noncoagulant properties including antiinflammatory actions . We have previously shown that heparin attenuates the methacholine-induced bronchoconstriction in humans . In contrast to methacholine , a stimulus that induces airway constriction mainly by " direct " stimulation of airway smooth muscle cells , adenosine airway responsiveness reflects " indirectly " induced airway narrowing via inflammatory mediators or neural reflex mechanisms . Whether heparin modulates bronchial hyperreactivity induced by adenosine , is not well known . We investigated the effect of inhaled heparin on adenosine-induced bronchoconstriction and compared the inhibitory role of heparin on the adenosine challenge test with that on the methacholine challenge test . Fifteen subjects ( 7 males , 8 females ) with mild asthma were included in the study . Bronchial provocation tests were performed in a single-blind , crossover , randomized order , and repeated 45 minutes after placebo or aerosolized heparin inhalation ( 1,000 U/kg ) . The heparin increased the geometric mean log methacholine PD20 value from 0.47 +/- 0.16 ( 2.95 mg/ml ) to 0.96 +/- 0.10 ( 8.91 mg/ml ) , ( P < 0.0009 ) in 15 patients and the geometric mean log adenosine PD20 values from 1.59 +/- 0.23 ( 38.9 mg/ml ) to 1.98 +/- 0.14 ( 97.7 mg/ml ) ( NS ) in 7 patients whose baseline adenosine PD20 levels were less than 200 mg/ml . The degree of protection by heparin against adenosine-induced bronchoconstriction was not correlated with that against methacholine-induced bronchoconstriction ( r = 0.60 , NS ) . The data suggest that inhaled heparin may have an inhibitory effect on the methacholine bronchial challenge , and thus , most likely directs its effect against smooth muscle . Heparin caused less attenuation of a challenge with adenosine and probably does not affect mast cell degranulation .
89842
Intervention_Pharmacological
heparin
89843
Intervention_Pharmacological
Glycosaminoglycan heparin
89844
Intervention_Pharmacological
heparin
89845
Intervention_Pharmacological
heparin
89846
Intervention_Pharmacological
inhaled heparin
89847
Intervention_Pharmacological
heparin
89848
Intervention_Control
placebo
89849
Intervention_Pharmacological
aerosolized heparin inhalation
89850
Intervention_Pharmacological
heparin
89851
Intervention_Pharmacological
heparin
89852
Intervention_Pharmacological
heparin
89853
Intervention_Pharmacological
Heparin
89854
Outcome_Other
geometric mean log methacholine PD20 value
89855
Outcome_Other
geometric mean log adenosine PD20 values
89856
Outcome_Other
degree of protection
89857
Participant_Condition
adenosine-induced bronchial hyperreactivity .
89858
Participant_Condition
humans
89859
Participant_Sample-size
Fifteen
89860
Participant_Sample-size
7
89861
Participant_Sex
males
89862
Participant_Sample-size
8
89863
Participant_Sex
females
89864
Participant_Condition
mild asthma