title: Normal alpha 2-adrenergic responses in platelets from patients with asthma.
abstract: recent in vivo studies suggest that alpha-adrenergic responses are exaggerated in asthmatic subjects. We studied alpha 2-adrenergic responses in platelets from 12 healthy subjects and 10 patients with asthma who had taken no medication for at least 9 days prior to study except low-dose (less than 600 micrograms daily) beclomethasone diproprionate. Alpha 2-adrenergic inhibiton of prostaglandin E1-stimulated adenosine 3':5; cyclic monophosphate (cAMP) accumulation was normal in platelets from subjects with asthma. The time course of inhibition, the extent of inhibition, and the dose-response relationship did not differ between the groups. Results from allergic and nonallergic patients did not differ, and alpha 2-adrenergic responses were not correlated with age, sex, peak flow rated, or total eosinophil counts. Platelet alpha 2-adrenergic cAMP responses are normal in subjects with asthma.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000328:Adult; D000527:Alprostadil; D001249:Asthma / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D000242:Cyclic AMP / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D011458:Prostaglandins E / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000316:Adrenergic alpha-Agonists; D011458:Prostaglandins E; D010656:Phenylephrine; D000242:Cyclic AMP; D000527:Alprostadil; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine