Role of nitric oxide in larval and juvenile fish.
Fish are known to express the three isoforms of nitric oxide synthase (NOS), the constitutive forms endothelial or eNOS, neuronal or nNOS and the inducible form iNOS. Most studies in fish have focussed on possible roles for NO in cardiovascular physiology although there has been recent attention on the role of nNOS in embryonic development. However compared to mammalian studies there have been relatively few studies on effects of nitric oxide (NO) on fish. Studies on heart and blood vessel preparations from various fish species appear to show results specific to the species or to the particular preparation. Possible roles of NO in the in vivo biology of adult fish or larval fish have received little attention. This article reviews effects of nitric oxide on cardiovascular physiology in fish with special emphasis on larval fish. It introduces some experimental work on possible signaling pathways in larval fish and introduces the possibility that NO could be an important environmental influence for some aquatic organisms. In higher vertebrates LPS (lipopolysaccharide) is known to activate the cytokine signaling system and stimulate increased expression of iNOS and increased production of NO, but this remains less investigated in fish. The effects of LPS on cardiovascular and osmoregulatory physiology of larval and juvenile salmonids are discussed and a possible role of NO in stress-induced drinking is suggested.
Biological Sciences Institute, Faculty of Life Sciences, University of Dundee DD1 4HN, UK. F.B.Eddy@dundee.ac.uk
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D000818:Animals; D001808:Blood Vessels / Q000378:metabolism; D002319:Cardiovascular System / Q000196:embryology*; D003621:Daphnia; D005399:Fishes / Q000196:embryology* / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D006339:Heart Rate; D008070:Lipopolysaccharides / Q000378:metabolism; D008954:Models, Biological; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D020033:Protein Isoforms; D012474:Salmon; D015398:Signal Transduction; D013045:Species Specificity; D013997:Time Factors
D008070:Lipopolysaccharides; D020033:Protein Isoforms; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase