title: Endomorphin-suppressed nitric oxide release from mice peritoneal macrophages.
abstract: Endomorphins are newly discovered mu-opioid receptor selective immunocompetent opioid peptides. Endomorphin 1 is predominantly distributed in brain, while endomorphin 2 is widely allocated in the spinal cord. Lately, endomorphins have been investigated as modulators of reactive oxygen and nitrogen species. Nitric oxide is short lived radical involved in various biological processes such as regulation of blood vessel contraction, inflammation, neurotransmission and apoptosis. The aim of this work was to investigate the in vivo effects of endomorphins on nitric oxide release and NOS 2 isoenzyme upregulation in mice peritoneal macrophages additionally challenged ex vivo with lipopolysaccharide. The results showed that endomorphin 1 or endomorphin 2 in vitro did not change NO release from peritoneal mouse macrophages during a 48 h incubation period. On the other hand in vivo endomorphins had suppressive effect on NO release as well as on NOS 2 and IL-1 protein concentration. The most of suppressive effect in vivo of both endomorphins was blocked with 30 min pretreatment with mu-receptor selective antagonist beta-FNA, which proved involvement of opioid receptor pathway in suppressive effects of endomorphins.
authors.affiliation: Division of Molecular Medicine, Rudjer Bosković Institute, Bijenicka cesta 54, Zagreb, Croatia. balog@irb.hr
authors.forename: Tihomir
authors.initials: T
authors.lastname: Balog
authors.forename: Ana
authors.initials: A
authors.lastname: Sarić
authors.forename: Sandra
authors.initials: S
authors.lastname: Sobocanec
authors.forename: Borka
authors.initials: B
authors.lastname: Kusić
authors.forename: Tatjana
authors.initials: T
authors.lastname: Marotti
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002469:Cell Separation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000096:biosynthesis; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D008808:Mice, Inbred CBA; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D007375:Interleukin-1; D009842:Oligopeptides; C105293:endomorphin 1; D009569:Nitric Oxide; C105294:endomorphin 2; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse