neuropeptide-y and Leukopenia

Neuropeptide Y (NPY) increases survival in experimental septic shock, which might be mediated by cardiovascular and/or immunological effects. To study the latter hypothesis, we monitored blood leukocyte subsets over 96 h after intravenous (i.v.) application of LPS in chronically i.v.-cannulated rats. LPS induced a dramatic leukopenia at 4 h after challenge, which was blunted in NPY-treated animals by stabilizing granulocyte and T-lymphocyte numbers. In addition, NPY treatment prevented tissue immigration of monocytes at early time points and consecutively mobilized activated monocytes from the third day after challenge. RT-PCR and in vitro adhesion studies provided evidence for a NPY Y2 receptor-mediated effect on monocytes. Thus, NPY treatment has profound receptor-specific effects on the migration and adhesion of leukocytes under endotoxemic conditions.

Topics: Animals; Apoptosis; Cell Adhesion; Cells, Cultured; Chemotaxis, Leukocyte; Down-Regulation; Endotoxemia; Flow Cytometry; Free Radicals; Injections, Intravenous; Leukopenia; Lipopolysaccharides; Male; Monocytes; Neuropeptide Y; Rats; Rats, Inbred Lew; Receptors, Neuropeptide Y; RNA, Messenger; T-Lymphocytes; Tumor Necrosis Factor-alpha