Effects of modulation of nitric oxide on rat diaphragm isotonic contractility during hypoxia.
J Appl Physiol (1985)
; 94(2): 612-20, 2003 Feb.
Article
in En
| MEDLINE
| ID: mdl-12391124
Nitric oxide (NO) is essential for optimal myofilament function of the rat diaphragm in vitro during active shortening. Little is known about the role of NO in muscle contraction under hypoxic conditions. Hypoxia might increase the NO synthase (NOS) activity within the rat diaphragm. We hypothesized that NO plays a protective role in isotonic contractile and fatigue properties during hypoxia in vitro. The effects of the NOS inhibitor N(G)-monomethyl-l-arginine (l-NMMA), the NO scavenger hemoglobin, and the NO donor spermine NONOate on shortening velocity, power generation, and isotonic fatigability during hypoxia were evaluated (Po(2) approximately 7 kPa). l-NMMA and hemoglobin slowed the shortening velocity, depressed power generation, and increased isotonic fatigability during hypoxia. The effects of l-NMMA were prevented by coadministration with the NOS substrate l-arginine. Spermine NONOate did not alter isotonic contractile and fatigue properties during hypoxia. These results indicate that endogenous NO is needed for optimal muscle contraction of the rat diaphragm in vitro during hypoxia.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Diaphragm
/
Spermine
/
Muscle Fatigue
/
Isotonic Contraction
/
Hypoxia
/
Nitric Oxide
Limits:
Animals
Language:
En
Journal:
J Appl Physiol (1985)
Journal subject:
FISIOLOGIA
Year:
2003
Document type:
Article
Affiliation country:
Países Bajos
Country of publication:
Estados Unidos