Williamson S A, Knight R A, Lightman S L, Hobbs J R
Department of Chemical Immunology, Charing Cross and Westminster Medical School, London, England.
Brain Behav Immun. 1987 Dec;1(4):329-35. doi: 10.1016/0889-1591(87)90035-3.
The endogenous opiate peptide, beta-endorphin, has two effects on human natural killing (NK). Preincubation of effector lymphocytes with between 10(-7) and 10(-11) M beta-endorphin increases NK. Preincubation with lower concentrations results in a reduction in NK. Endorphin peptides containing an unmodified N-terminal sequence, and which are known to bind only to opiate receptors, increase NK. Sequences reported to bind only to nonopiate receptors reduce NK.
