Effect of beta-adrenergic blockade and sympathetic stimulation on canine bronchial mast cell response to immune degranulation in vivo

We examined the effect of beta-adrenoceptor blockade and residual alpha-adrenoceptor effects during sympathetic stimulation on mast cell secretion of histamine in 12 natively allergic mongrel dogs. Bronchial mast cell response was measured as the arteriovenous difference (AVd) in plasma histamine concentration [H] across the bronchus. Plasma [H] was determined simultaneously from the azygos outflow tract and femoral artery as a marker of mast cell response prior to and for 90 s after intra-arterial injection of sham diluent and 1:100 and 1:30 dilutions of Ascaris suum antigen. Sympathetic (alpha-adrenergic) stimulation was elicited with continuous infusion of the nicotinic agonist, dimethylphenylpiperazinium (DMPP) under conditions of muscarinic blockade with atropine and beta-adrenoceptor blockade with propanolol. Plasma epinephrine (EPI) increased from 315 ± 106 to 34,127 ± 10,711 pg/ml (p < 0.02). Control animals receiving sham infusion in place of sympathetic stimulation additionally had neural blocka...