Inhibition of LPS-induced TNF-alpha production by calcitonin gene-related peptide (CGRP) in cultured mouse peritoneal macrophages.
The purpose of this study was to examine whether rCGRP has effects on TNF-alpha produced by mouse resident peritoneal macrophages. Macrophages were obtained from the peritoneal exudate of male Balb/c mouse. The cells were plated on culture dishes at a density of 2.5x10(5) cells per well and allowed to adhere for 2 hr. Pretreatment with rCGRP (10 nM-1 microM) for 24 hr, the macrophages were cultured with LPS 1 microg/ml for another 24 h. The medium was harvested for measuring TNF-alpha by ELISA kits. The results showed that rCGRP had no direct effects on TNF-alpha production, but it inhibited LPS-induced TNF-alpha production in a concentration-dependent manner. When rCGRP was at a concentration of 1 microM, the LPS-induced TNF-alpha production was inhibited by 39%. The effect of rCGRP was reversed by hCGRP(8-37) (10 microM), an antagonist of CGRP1 receptor. The LPS-induced TNF-alpha production from macrophages was also inhibited by forskolin 3 microM, an activator of adenylate cyclase. Furthermore, pretreatment with H-89 1 microM or Rp-cAMPS 100 microM, the inhibitors of cAMP-dependent protein kinase, the effect of rCGRP was abolished. These data suggest that the LPS-induced TNF-alpha production is inhibited by rCGRP via activation of cAMP responses in mouse resident peritoneal macrophages.
Feng
Y
Y
Institute of Vascular Medicine, Third Hospital, Beijing Medical University, P.R. of China.
Tang
Y
Y
Guo
J
J
Wang
X
X
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000494:pharmacology; D013449:Sulfonamides; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D004791:Enzyme Inhibitors; D007546:Isoquinolines; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D013449:Sulfonamides; D014409:Tumor Necrosis Factor-alpha; D017868:Cyclic AMP-Dependent Protein Kinases; D015740:Calcitonin Gene-Related Peptide; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D015056:1-Methyl-3-isobutylxanthine