Endogenous nitric oxide synthase inhibitor increase skeletal muscle con-tractility and mitochondria biosynthesis in 4-week running rats / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To observe the effect of endogenous nitric oxide synthase ( NOS) inhibitor asymmetric dimeth-ylarginine ( ADMA ) and its signaling pathways on NO levels and skeletal muscle contractility in 4-week running rats. METHODS:The 4 weeks running rat model was established.The twitch tension, tetanic tension and the fatigue test of sole-us muscle induced by electrical stimulation ex vivo were detected.The ATP content, mitochondrial DNA levels and the mR-NA expression of peroxisome proliferator-activated receptor γcoactivator-1α(PGC-1α), nuclear respiratory factor (NRF) were measured to reflect the mitochondrial function and biosynthesis in the skeletal muscle.Serum ADMA concentration was detected by high performance liquid chromatography.The endogenous ADMA enzymes PRMT1 and 2 subtypes of ADMA me-tabolism enzyme DDAH, 3 subtypes of NOS protein expression in the skeletal muscle were determined by Western blot.NOS activity and nitric oxide ( NO) content were analyzed by colorimetric method.RESULTS: Compared with normal control group, the twitch tension, tetanic tension and the anti-fatigue capability of soleus muscle in running group were significantly enhanced, ATP content, mitochondrial DNA content and the mRNA expression of PGC-1αand NRF were significantly in-creased (P ance of soleus muscle.The mechanism may be that increased cNOS expression feedbacks to increase ADMA concentration, thus maintaining the increase in NO synthesis at a relatively low level, and resulting in promoting skeletal muscle mitochon-dria biosynthesis and mitochondrial function.