title: Bleeding time and PAF-acether-induced platelet aggregation in atopy.
abstract: In a double-blind cross-over study 20 mg of aspirin or placebo were administered to 18 patients with respiratory atopy without eczema and to 12 healthy controls. Mean bleeding time before administration of either aspirin or placebo was on average about 1 min. longer in atopics than in the controls, and this difference was significant (p 0.05). Atopics' platelets also aggregated less well in response to arachidonic acid in comparison to controls. On the contrary, no difference in platelet aggregability was detected in response to either PAF-acether alone or to combination of subthreshold, synergistic concentrations of PAF-acether and collagen. Aspirin at a dose used did not affect either bleeding time or platelet aggregability. Thus, in respiratory atopy there exists a moderate hemostatic imbalance, the reason of which remains to be established.
mesh_terms: D000328:Adult; D001241:Aspirin / Q000494:pharmacology; D001249:Asthma / Q000097:blood*; D001760:Bleeding Time; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010972:Platelet Activating Factor; D010974:Platelet Aggregation / Q000187:drug effects; D010979:Platelet Function Tests; D006255:Rhinitis, Allergic, Seasonal / Q000097:blood*
chemical_list: D010972:Platelet Activating Factor; D001241:Aspirin