BETA-ADRENERGIC RECEPTORS MEDIATE IN-VIVO THE ADRENALINE INHIBITION OF LIPOPOLYSACCHARIDE-INDUCED TUMOR-NECROSIS-FACTOR RELEASE

Adrenaline has been shown to inhibit the release of tumor necrosis fac tor (TNF) elicited by lipopolysaccharide (LPS) when tested in vitro on cultured human blood cells and rat macrophages. In this report we hav e examined the effect of the in vivo administration of adrenaline on T NF serum levels induced by LPS. In agreement with in vitro data, adren aline (0.1 mg/kg, s.c.) was found to inhibit in the mouse the LPS-indu ced TNF release. The beta-adrenergic antagonist propranolol administer ed 1 h before adrenaline completely blocked the adrenaline activity, w hereas the alpha-adrenergic antagonist phentolamine was ineffective. T hese data demonstrate that: (i) adrenaline is an effective antagonist of LPS-induced TNF release in vivo, and (ii) its effect is mediated by adrenergic receptors.