Nitrite modulates contractility of teleost (Anguilla anguilla and Chionodraco hamatus, i.e. the Antarctic hemoglobinless icefish) and frog (Rana esculenta) hearts.
Biochim Biophys Acta
; 1787(7): 849-55, 2009 Jul.
Article
em En
| MEDLINE
| ID: mdl-19298789
ABSTRACT
Being the largest form of intravascular and tissue storage of nitric oxide (NO) and a signalling molecule itself, the nitrite anion (NO(2)(-)) has emerged as a key player in many biological processes. Since the heart is under an important NO-mediated autocrine-paracrine control, in mammals the cardiac effects of nitrite are under intensive investigation. In contrast, nothing is known in non-mammalian vertebrates. We evaluated nitrite influence on cardiac performance in the perfused beating heart of three different cold-blooded vertebrates, i.e. two teleost fishes, the temperate red-blooded Anguilla anguilla, the Antarctic stenotherm, hemoglobinless Chionodraco hamatus (icefish), and the frog Rana esculenta. We showed that, under basal conditions, in all animals nitrite influences cardiac mechanical performance, inducing negative inotropism in eel and frog, while being a positive inotrope in C. hamatus. In all species, these responses parallel the inotropic effects of authentic NO. We also demonstrated that the nitrite-dependent inotropic effects are i) dependent from NO synthase (NOS) activity in fish; ii) sensitive to NO scavenging in frog; iii) cGMP/PKG-dependent in both eel and frog. Results suggest that nitrite is an integral physiological source of NO and acts as a signalling molecule in lower vertebrate hearts, exerting relevant inotropic actions through different species-specific mechanisms.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Rana esculenta
/
Perciformes
/
Anguilla
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Contração Miocárdica
/
Nitritos
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article