title: The in vitro effects of endogenous opiates on natural killer cells, antigen-specific cytolytic T cells, and T-cell subsets.
abstract: In concert with the known effects of stress on immune function, we examined a possible neurohumoral connection. The endogenous opiates beta-endorphin, dynorphin, and methionine-enkephalin were assessed for their in vitro effects on human natural killer cell activity, antigen-specific cytolysis, and numbers and ratios of T cells and T-cell subsets. Preincubation with beta-endorphin, an opiate released into the circulation during various stresses, caused a 50% reduction in natural killer cell activity. All endogenous opiates significantly decreased antigen-specific cytolysis. Inhibition of cytolysis in vitro was not mediated through an alteration of T-cell subsets or inhibition of T-cell soluble factors (interleukin 2). The direct effects of these opiates on cytolytic T-cell and natural killer cell function may provide a link between stress and disease susceptibility.
mesh_terms: D003602:Cytotoxicity, Immunologic; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000187:drug effects*; D009294:Narcotics / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000145:classification / Q000187:drug effects*
chemical_list: D009294:Narcotics