Modulation of lipopolysaccharide-induced tumor necrosis factor-alpha production by selective alpha- and beta-adrenergic drugs in mice.
In a previous study we demonstrated that mice pretreated with the highly selective alpha 2-adrenoceptor antagonist CH-38083 showed blunting of the tumor necrosis factor-alpha (TNF-alpha) response induced by bacterial lipopolysaccharide (LPS). In the present study, the effect of a selective block of alpha 2-adrenoreceptors and the role of the sympathetic nervous system (SNS) in the regulation of LPS-induced TNF-alpha production was explored further using different selective adrenoceptor antagonists and agonists. While adrenalectomy did not prevent the effect of CH-38083, the block of the sympathetic transmission by chlorisondamine fully abolished the inhibitory effect of CH-38083 on LPS-induced TNF-alpha production, suggesting that the effect of the alpha 2-adrenoceptor blocking agent is corticosteroid-independent, but it requires intact sympathetic activity. Since the selective block of alpha 2-adrenoceptors results in an increased sympathetic activity and an increase of the release of noradrenaline (NA) in both the central and the peripheral nervous systems, and in our experiments propranolol, a non-selective beta-adrenoceptor antagonist, and atenolol, a selective antagonist of beta 1-adrenoceptors, prevented the effect of alpha 2-adrenoceptor blockade by CH-38083 of the TNF-alpha response induced by LPS, it seems likely that the excessive stimulation by NA of beta 1-adrenoceptors is responsible for this action. The role of beta-adrenoceptors and endogenous catecholamines is further substantiated by the finding that pretreatment of animals with propranolol alone resulted in a dose-dependent increase of the TNF-alpha response induced by LPS, and that isoproterenol, a non-selective beta-adrenoceptor agonist, decreased it.(ABSTRACT TRUNCATED AT 250 WORDS)
Elenkov
I J
IJ
Department of Pharmacology, Hungarian Academy of Sciences, Budapest, Hungary.
Haskó
G
G
Kovács
K J
KJ
Vizi
E S
ES
D000315:Adrenalectomy; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001599:Berberine / Q000031:analogs & derivatives / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D011433:Propranolol / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D001599:Berberine; C048886:7,8-(methylenedioxy)-14-hydroxyberbane; D011433:Propranolol