Immunochemical and Biologic Properties of Rat IgE

[摘要] The antigen-induced release of slow-reacting substance of anaphylaxis (SRS-A) in rats prepared with IgE antibody is markedly influenced by agents which act to increase or decrease the levels of cellular cyclic 3′,5′-adenosine monophosphate (cyclic-AMP). Three lines of evidence indicate that the intracellular accumulation of cyclic-AMP suppresses SRS-A release: β-adrenergic stimulation with isoproterenol or epinephrine is inhibitory; methylxanthine derivatives inhibit in a dose-response fashion; and synergism is observed when isoproterenol and aminophylline are used together. Conversely, depletion of cellular cyclic-AMP through direct α-adrenergic stimulation with norepinephrine enhances IgE-mediated SRS-A release. Agents known to be specific α- or β-adrenergic antagonists were employed to establish the specificity of the effects observed with the catecholamines. The β-adrenergic blocking agent, propranolol, prevents the inhibition observed with isoproterenol but has no effect on that observed with aminophylline. The α-adrenergic blocking agent phenoxybenzamine prevents the enhancement of SRS-A release achieved with norepinephrine and enhances the inhibition produced with epinephrine. The implication that the intracellular accumulation of cyclic-AMP inhibits the IgE-mediated release of SRS-A is further supported by the observation that exogenous administration of dibutyryl cyclic-AMP inhibits SRS-A release in a dose-response fashion.

[学科分类] 生物科学（综合）