Stimulation of phagocytosis in mouse peritoneal macrophages by orexin-B and orexin-A

抄録

To define the effects of feeding and sleep regulating peptides, orexins, in immunocompetent cells, the effects of orexin-A and orexin-B on phagocytosis in mouse peritoneal macrophages were examined. Orexin-B induced an enhancement of phagocytosis in a dose-dependent manner. Orexin-A is less effective than orexin-B. Even in Ca²⁺-free solutions, phagocytosis was enhanced by orexin-B. The potassium channel blocker quinine inhibited the enhanced phagocytosis by orexin-B; 4-aminopyridine and tetraethylammonium suppressed phagocytosis less effectively. These results suggest that orexins can enhance the phagocytosis of macrophages mediated by potassium channels.