Enhancement of phagocytosis by dynorphin A in mouse peritoneal macrophages.
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), beta-neo-endorphin (beta Neo-End), DynA(9-17) and DynA(13-17) had no such activity. Alpha-Neo-endorphin (alpha Neo-End), dynorphin B (DynB), DynA(1-13) 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 Ca2+-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 Ca2+-free solution. The present study showed that enhancement of phagocytosis by DynA was independent of extracellular Ca2+ ([Ca2+]o) and dependent on intracellular Ca2+ ([Ca2+]i). The present results support DynA being one of the mediators from the nervous system that modulates the immune system.
Ichinose
M
M
Department of Physiology, Shimane Medical University, Izumo, Japan.
Asai
M
M
Sawada
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D004399:Dynorphins / Q000737:chemistry / Q000494:pharmacology*; D005110:Extracellular Space / Q000378:metabolism; D005434:Flow Cytometry; D007425:Intracellular Membranes / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009270:Naloxone / Q000494:pharmacology; D018847:Opioid Peptides / Q000737:chemistry / Q000494:pharmacology; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects*
D018847:Opioid Peptides; D010446:Peptide Fragments; D009270:Naloxone; D004399:Dynorphins; D002118:Calcium