title: Regulation of nitric-oxide production in hemocytes of the ascidian Phallusia nigra.
abstract: Nitric oxide (NO) production in ascidians is related to immune responses of blood cells, and also to events such as egg fertilization and notochord regression. However, the signaling pathway for NO generation has been little investigated in this animal model. The present contribution identifies the cells involved in NO production and provides new information about a pathway for NO signaling. We were able to identify eight types of blood cells in the hemolymph of the ascidian Phallusia nigra, of which signet ring cells, univacuolar refractile granulocytes, and morula cells were involved in NO production. Zymosan A and lipopolysaccharide (LPS) enhanced NO production by blood cells, and the compound N-nitro-L-arginine-methyl ester (L-NAME) reduced NO production. Finally, the application of protein kinase A (PKA) and protein kinase C (PKC) inhibitors revealed that these molecules participate, together with NFκB, in the regulation of NO production by blood cells of P. nigra. This is the first report to show that PKA and PKC are involved in a signaling pathway that leads to NO production in ascidian blood cells.
authors.affiliation: Laboratório Integrado de Morfologia, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro - UFRJ, Macaé, RJ, Brazil.
authors.forename: Cintia M
authors.initials: CM
authors.lastname: de Barros
authors.affiliation: Laboratório Integrado de Morfologia, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro - UFRJ, Macaé, RJ, Brazil.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Emrich
authors.affiliation: Laboratório Integrado de Morfologia, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro - UFRJ, Macaé, RJ, Brazil.
authors.forename: Andressa
authors.initials: A
authors.lastname: de A Mello
authors.affiliation: Laboratório Integrado de Bioquímica Hatisaburo Masuda, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro - UFRJ, Macaé, RJ, Brazil.
authors.forename: Rodrigo N
authors.initials: RN
authors.lastname: da Fonseca
authors.affiliation: Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil. Electronic address: sallodi@biof.ufrj.br.
authors.forename: Silvana
authors.initials: S
authors.lastname: Allodi
mesh_terms: D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006434:Hemocytes / Q000187:drug effects / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship; D014561:Urochordata / Q000166:cytology*; D015054:Zymosan / Q000494:pharmacology
chemical_list: D008070:Lipopolysaccharides; D009569:Nitric Oxide; D015054:Zymosan; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D019331:NG-Nitroarginine Methyl Ester
keywords: Ascidian; Blood cells; Nitric oxide; Protein kinases