[Cellular and molecular mechanisms of regulation of immune functions by catecholamines].

An increasing body of evidence suggests that catecholamines (CAs) do not only cause a general immunosuppression as previously believed, but suppress cellular immunity and boost humoral response. CAs can inhibit T helper 1 cells, T cytotoxic cells, natural killer cells and monocytes, but enhance T helper 2 cells and B cells through their direct regulation of these immune cells. In addition, CAs may modulate the gene transcription for cytokines in immune cells through stimulation of beta 2-adrenoreceptors and increase of cAMP, subsequently, activation of protein kinase A and alteration of the activity of nuclear transcription factors. Through these molecular mechanisms, the production of interleukin-2 (IL-2), tumor necrosis factor-alpha and IL-12 is decreased, but the production of IL-6, IL-10 and IL-4 is increased.