title: Coronary anaphylaxis in vitro.
abstract: 1 The reactivity of isolated coronary arteries and cardiac veins of the calf to selected chemical mediators of anaphylaxis and to sensitizing antigen (horse plasma) was studied. 2 Both the coronary arteries and cardiac veins contracted to bradykinin, 5-hydroxytryptamine (5-HT), prostaglandin E2 (PGE2), PGF2 alpha, histamine and carbachol. 3 Isoprenaline and PGE1 relaxed vessels which had been partially contracted by PGF2 alpha, PGE2, histamine, 5-HT, bradykinin, carbachol or antigen. 4 Horse plasma (antigen) contracted coronary vessels obtained from sensitized calves, but not from control calves. Subsequent antigen 'challenge' produced 'densensitization' (tachphylaxis). After 1 or 2 h of rest, the anaphylactic response partially recovered although there was no change in tissue reactivity to the exogenous agonists. 5 Specific doses of atropine, mepyramine (H1-blocker) and methysergide (5-HT antagonist) did not modify the anaphylactic reaction in coronary arteries, suggesting a negligible role for these biogenic amines. 6 Compound PRD-92-EA (a new anti-allergic agent) exhibited non-specific receptor blocking activity towards histamine, 5-HT and carbachol and inhibited the coronary anaphylactic reaction.
mesh_terms: D000707:Anaphylaxis / Q000276:immunology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D003331:Coronary Vessels / Q000276:immunology*; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011738:Pyrilamine / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology
chemical_list: D012701:Serotonin; D001285:Atropine; D006632:Histamine; D002217:Carbachol; D011738:Pyrilamine; D008784:Methysergide