Enhancement of phagocytosis by dynorphin A in mouse peritoneal macrophages

• Published in: Journal of neuroimmunology 1995-07, Vol.60 (1), p.37-43
• Main Authors: Ichinose, Mitsuyuki, Asai, Masatoshi, Sawada, Masashi
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Calcium - metabolism; Dynorphin A; Dynorphins - chemistry; Dynorphins - pharmacology; Extracellular Space - metabolism; Flow Cytometry; Intracellular Membranes - metabolism; Macrophages; Macrophages, Peritoneal - drug effects; Macrophages, Peritoneal - physiology; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Naloxone - pharmacology; Opioid Peptides - chemistry; Opioid Peptides - pharmacology; Osmolar Concentration; Peptide Fragments - pharmacology; Phagocytosis; Phagocytosis - drug effects
• ISSN: 0165-5728; 1872-8421
• DOI: 10.1016/0165-5728(95)00050-C

The effects of the opioid peptide dynorphin A (DynA) on phagocytosis in peritoneal macrophages was examined by flow cytometry (FCM). DynA enhanced phagocytosis in a dose-dependent manner. Leucine-enkephalin (Leu-Enk), methionine-enkephalin (Met-Enk), β-neo-endorphin (βNeo-End), DynA(9–17) and DynA(13–17) had no such activity, α -Neo-endorphin (α Neo-End), dynorphin B (DynB), DynA(l–13) and DynA(6–17) enhanced phagocytosis less effectively than DynA. Naloxone did not inhibit the enhancement of phagocytosis induced by DynA. Unstimulated control phagocytosis was partially suppressed in Ca 2+-free EGTA-containing solution and even in this solution DynA enhanced phagocytosis. However, the enhancement by DynA was suppressed in EGTA- and BAPTA-AM-containing Ca 2+-free solution. The present study showed that enhancement of phagocytosis by DynA was independent of extracellular Ca 2+ ([Ca 2+] o) and dependent on intracellular Ca 2+ ([Ca 2+] i). The present results support DynA being one of the mediators from the nervous system that modulates the immune system.