Real-time measurement of nitric oxide in single mature mouse skeletal muscle fibres during contractions.

摘要: Nitric oxide (NO) is thought to play multiple roles in skeletal muscle including regulation of some adaptations contractile activity, but appropriate methods for the analysis intracellular NO activity are lacking. In this study we have examined generation isolated single mature mouse fibres at rest and following a period activity. Muscle were from flexor digitorum brevis mice production was visualized real-time using fluorescent probe 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate (DAF-FM DA). Some leakage DAF-FM apparent loaded with probe, they retained sufficient respond changes addition donor 3-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-propanamine (NOC-7) up 30 min after loading. Electrically stimulated contractions increased rate change fluorescence by ∼48% compared non-stimulated (P < 0.05) returned control values 5 contractions. Treatment synthase inhibitors NG-nitro-l-arginine methyl ester hydrochloride (l-NAME) or NG-monomethyl-l-arginine (l-NMMA) reduced increase observed response untreated fibres. cell-permeable superoxide scavenger 4,5-dihydroxy-1,3-benzenedisulphonic acid (Tiron) also during suggesting that superoxide, more probably peroxynitrite, contributes observed. Thus technique can be used examine quiescent contracting real time, although peroxynitrite other reactive nitrogen species may potentially contribute