Reversal by methylene blue of tetanic fade induced in cats by nitric oxide
Braz. j. med. biol. res
; 31(3): 413-5, Mar. 1998. graf
Artigo
em Inglês
| LILACS
| ID: lil-212277
Biblioteca responsável:
BR1.1
ABSTRACT
Previous data from our laboratory have indicated that nitric oxide (NO) acting at the presynaptic level increases the amplitude of muscular contraction (AMC) of the phrenic-diaphragm preparations isolated from indirectly stimulated rats, but, by acting at the postsynaptic level, it reduces the AMC when the preparations are directly stimulated. In the present study we investigated the effects induced by NO when tetanic frequencies of stimulation were applied to in vivo preparations (sciatic nerve-anterior tibial muscle of the cat). Intra-arterial injection of NO (0.75-1.5 mg/kg) induced a dose-dependent increase in the Wedensky inhibition produced by high frequencies of stimulation applied to the motor nerve. Intra-arterial administration of 7.2 mug/Kg methylene blue did not produce any change in AMC at low frequencies of nerve stimulation (0.22 Hz), but antagonized the NO-induced Wedensky inhibition. The experimental data suggest that NO-induced Wedensky inhibition may be mediated by the guanylate cyclase-cGMP pathway.
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Tetania
/
Azul de Metileno
/
Contração Muscular
/
Antídotos
/
Óxido Nítrico
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
1998
Tipo de documento:
Artigo