Modulation of fish phagocytic cells by N-terminal peptides of proopiomelanocortin (NPP).
N-terminal peptide of proopiomelanocortin (NPP, or pro-gamma-MSH) has shown to exhibit biological activity such as stimulation of adrenal mitogenesis and prolactin release-inhibiting factor activity. Structurally, studies reveal a significant difference between fish NPP from that of tetrapods, as NPPs from carp and salmonid lack gamma-MSH. Thus, fish NPP may exhibit functions different from that of mammals. The activation of phagocytic cells by NPP was analysed using rainbow trout Oncorhynchus mykiss and carp Cyprinus carpio. Rainbow trout and carp macrophages incubated with chum salmon NPP significantly enhanced the production of superoxide anion in comparison with control macrophages (without hormones). Both rainbow trout and carp macrophages had shown increased phagocytosis when stimulated administered with NPP. The above results were complemented by in vivo studies where NPP was administered to rainbow trout and carp. NPP significantly increased superoxide anion production as well as phagocytosis in macrophages. These results show that NPP in lower vertebrates activates the function of the phagocytic cells.
Sakai
M
M
Faculty of Agriculture, Miyazaki University, Miyazaki, 889-2192, Japan. m.sakai@miyazaki-u.ac.jp
Yamaguchi
T
T
Watanuki
H
H
Yasuda
A
A
Takahashi
A
A
D000818:Animals; D002347:Carps / Q000502:physiology*; D017686:Oncorhynchus mykiss / Q000502:physiology*; D010586:Phagocytes / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology; D011333:Pro-Opiomelanocortin / Q000494:pharmacology*; D013481:Superoxides
D013481:Superoxides; D011333:Pro-Opiomelanocortin