CATECHOLAMINES INDUCE ALTERATIONS OF DISTRIBUTION AND ACTIVITY OF HUMAN NATURAL-KILLER (NK) CELLS

Catecholamines have been suggested to be responsible for altered cellu lar immunity after stress. This study was performed to determine the e ffects of adrenaline and noradrenaline on lymphocyte subpopulations an d NK cell functions. Subjects were given a subcutaneous injection of e ither NaCl, adrenaline (5 mug/kg), or noradrenaline (10 mug/kg). Catec holamine concentrations, subsets of peripheral blood lymphocytes, NK a ctivity, and antibody-dependent cellular cytotoxicity (ADCC) were anal yzed before (baseline) and 5, 15, 30, 60, and 120 min after injection. There were no differences between groups in the distribution of CD2and CD8+ lymphocytes over time. However, CD3+ and CD4+ T cells decreas ed significantly 5 to 60 min after injection of adrenaline. In contras t, NK cell numbers (CD16+, CD56+) increased significantly 5 min after injection of adrenaline and noradrenaline, reached the highest values 15 to 30 min postinjection, and subsequently declined to baseline valu es 60 (noradrenaline) and 120 (adrenaline) min, respectively, after in jection. Similar alterations for NK activity and ADCC were observed af ter administration of both catecholamines. These data suggest that bot h sympathetic-adrenal hormones are similarly potent modulators of natu ral immunity and provide further evidence that catecholamines might be responsible for the observed alterations in immune functions after ph ases of acute stress.