BETA(2)-ADRENERGIC ACTIVATION ENHANCES INTERLEUKIN-8 PRODUCTION BY HUMAN MONOCYTES

Interleukin-8 (IL-8) is an important cytokine in inflammatory processe s by functioning as a chemoattractant and as an activator of oxygen me tabolism. In the present study we demonstrate that beta(2)-adrenergic agonists potentiate the lipopolysaccharide (LPS) and IL-1 induced prod uction of IL-8 by human monocytes. In addition. beta(2)-adrenergic act ivation enhances IL-8 release and mRNA expression for IL-8 in the huma n monocytic cell line U937. beta(2)-adrenergic activation of these cel ls also results in enhanced production of the anti-inflammatory cytoki ne IL-IO. However, IL-IO is not involved in the regulation of IL-8 pro duction. The effect of the beta(2)-adrenergic agonist on IL-8 producti on is presumably mediated via increased cAMP formation, since it can b e mimicked by the cAMP analogue dibutyryl-cAMP (db-cAMP). We conclude that enhancement of IL-8 production is one of the pathways via which b eta(2)-adrenergic agonists such as catecholamines can influence inflam matory responses.