Central noradrenergic & dopaminergic modulation of brewer's yeast-induced inflammation & nociception in rats.

The possibility of central noradrenergic and dopaminergic modulation of Brewer's yeast-induced peripheral inflammation was investigated in rats. Centrally administered noradrenaline (NA), amphetamine, which liberates NA and dopamine in the central nervous system and L-dopa, the precursor of dopamine significantly suppressed paw oedema. Conversely, the beta-adrenoceptor blocker, propranolol, catecholaminergic neuron degenerator, 6-hydroxydopamine (6-OHDA), dopaminergic antagonist, haloperidol and dopamine synthesis inhibitor, alpha-methyl para tyrosine (AMPT) augmented paw oedema. In addition, 6-OHDA and haloperidol produced significant reduction in pain threshold. The results of this study indicate that central NA and dopamine exert inhibitory effects on Brewer's yeast-induced peripheral inflammation.