DIFFERENTIAL-EFFECTS OF GASTRIN-RELEASING PEPTIDE, NEUROPEPTIDE-Y, SOMATOSTATIN AND VASOACTIVE-INTESTINAL-PEPTIDE ON INTERLEUKIN-1-BETA, INTERLEUKIN-6 AND TUMOR-NECROSIS-FACTOR-ALPHA PRODUCTION BY WHOLE-BLOOD CELLS FROM HEALTHY-YOUNG AND OLD SUBJECTS

In the present study, we have investigated the effect in vitro of gast rin-releasing peptide (GRP, 10(-10) M), neuropeptide Y (NPY, 10(-10) M ), somatostatin (10(-10) M) and vasoactive intestinal peptide (VIP, 10 (-9) M) on the production of IL-1 beta, IL-6 and TNF alpha by peripher al whole blood cells from healthy young and old people. We have found that GRP, NPY, somatostatin and VIP stimulated the production of IL-1 beta in old subjects, and NPY, somatostatin and VIP in young ones. In addition, the production of IL-6 was enhanced by GRP, NPY and VIP in y oung and old people. The TNF alpha production was stimulated by NPY an d somatostatin in young subjects, and by NPY, somatostatin and VIP in old ones, whereas GRP produced a decrease of TNF alpha in young person s. GRP in old subjects and VIP in young and old subjects stimulated in a great degree the LPS-induced IL-6 production by whole blood cells. On the contrary, GRP and VIP inhibited highly the LPS-induced TNF alph a production in young controls. Our results show that these neuropepti des, when added to whole blood cells at physiological concentrations, are able to stimulate the production of IL-1 beta, IL-6 and TNF alpha in a differential way according to the subject age.