Effect of beta-adrenergic stimulation on experimental canine anaphylaxis in vivo

We studied beta-adrenergic modulation of antigen-induced release of histamine and changes in lung function in natively allergic, anesthetized dogs. After thoracotomy and bilateral cervical vagotomy, samples of peripheral lung frozen in situ were obtained for measurement of adenosine cyclic 3',5'-monophosphate (cAMP) and histamine. In 11 dogs with beta-adrenergic blockade (propranolol), subsequent Ascaris suum antigen (intravenous) decreased lung tissue histamine 21.5% +/- 5.3% (mean +/- SE), with marked physiologic changes of anaphylaxis. In six other dogs, with no pharmacologic treatment before antigen, A. suum decreased lung tissue histamine only 11.5% +/- 1.9%. In six other dogs, terbutaline (1 mg/kg, i.v.) increased concentration of cAMP in peripheral lung, indicating stimulation of beta-adrenergic receptors, and inhibited response to A. suum. When a beta-adrenergic agonist was given 15 sec prior to A. suum, cAMP doubled and inhibition was incomplete. When a beta-agonist was given 150 sec prior to A. suum, cAMP increased fivefold and inhibition was complete.