CHANGES WITH AGING IN THE MODULATION OF MURINE LYMPHOCYTE CHEMOTAXIS BY CCK-8S, GRP AND NPY

The general immunodepression found in ageing organisms may be related to changes in the neuroimmune network. In the present study, the migra tion capacity of lymphocytes from BALB/c mice of three different ages: young (12 +/- 2 weeks), adult (24 +/- 2 weeks) and old (72 +/- 2 week s), has been assayed in vitro in response to three neuropeptides: sulf ated cholecystokinin octapeptide (CCK-8s), gastrin-releasing peptide ( GRP) and neuropeptide Y (NPY) in a physiological range of concentratio ns (10(-8)-10(-12) M). The capacity of migration to a chemical gradien t or chemotaxis was studied by the Boyden's technique using f-met-leu- phe at 10(-8) M as chemoattractant. The results show a different respo nse of lymphocytes to the different neuropeptides, as wells as to age, concentrations and locations studied. However, some similarities were found, for instance the three neuropeptides inhibited chemotaxis in t hymus. The stimulatory effects that GRP and NPY exerted in young and a dult mice were not observed in old animals. CCK-8s inhibited the chemo taxis in every organ studied, with the effect being more striking in o ld mice. Our conclusion is that stimulatory effects of the neuropeptid es disappear or become inhibitory with ageing. (C) 1998 Elsevier Scien ce Ireland Ltd. All rights reserved.