The effect of bombesin-related peptides on the phagocytic function of mouse phagocytes in vitro.

Bombesin (BBS) at doses of 0.1, 1.0, 10.0 and 100.0 nM stimulated chemiluminescence (CL) production by phagocytic cells (monocytes, macrophages and polymorphonuclear leucocytes) in mice in the presence of ZAP (opsonized zymosan particles containing luminol). These data suggest that BBS increased the phagocytic function of mouse phagocytes. BBS-related peptides, gastrin-releasing peptides (GRP)-27, GRP-14, GRP-10 and neuromedin B, also induced similar CL responses compared with BBS. The CL response elicited by BBS was depressed dramatically by various concentrations of EGTA (a Ca++ chelator), indicating that a Ca++ pathway may play a key role in the BBS-stimulated CL response.