title: The effect of dipyridamole on histamine- and adenosine-induced bronchoconstriction in normal and asthmatic subjects.
abstract: The effect of intravenous infusion of dipyridamole on histamine- and adenosine-induced bronchoconstriction was studied in 6 normal and 6 allergic asthmatic subjects. Dipyridamole in a single dose of 50 mg over 50 min had no effect upon baseline airway calibre measured as specific airways conductance (sGaw) and the forced expiratory volume in 1 s (FEV1). In the asthmatic subjects adenosine-induced bronchoconstriction was potentiated to a small extent by dipyridamole as indicated by a decrease in the concentration of adenosine required to produce falls from baseline of 40% for sGaw (PCs40) and 20% for FEV (PCf20) from 0.48 mg/ml to 0.32 and 0.37 mg/ml respectively. Dipyridamole had a small protective effect on histamine-induced bronchoconstriction with PCs40 and PCf20 increasing from 0.08 mg/ml to 0.11 and 0.17 mg/ml. In normal subjects dipyridamole failed to reveal a bronchoconstrictor effect of adenosine. These studies demonstrate the complex interaction between dipyridamole and bronchoconstrictor stimuli on the airways.
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000009:adverse effects*; D000281:Administration, Intranasal; D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001980:Bronchi / Q000503:physiopathology*; D004176:Dipyridamole / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D007263:Infusions, Parenteral; D008297:Male; D008875:Middle Aged
chemical_list: D004176:Dipyridamole; D006632:Histamine; D000241:Adenosine