The Relation Of The Change In NF-KB To Mitochondrion Permeability Transition Pore (MPTP) And Apoptosis In Denervated Skeletal Muscle Of Rats

Objective: To analyzed relationship of nuclear factor of kappaB with mitochondrion permeability transition pore(MPTP) and apoptosis during denervated atrophy of the gastrocnemius, and their potential roles in skeletal muscle atrophy.Methods: Thirty adult wista rats of either gender, weight (200±10) g. randomly divided into four group: group A (n =6, normal control group); group B ( n = 6, 2 days group); group C (n = 6, 7 days group); group D (n = 6, 14 days group); group E (n = 6, 28 days group). The rats were only exposed the sciatic nerve without cutting off in group A, and were made denervated gastrocnemius models in groups B to E. After 2 days, 7days, 14days, 28days of operation., the gastrocnemius was harvested to measure the ratio of muscle wet weight; levels of NF- kappaB p65 protein and the opening of the mitochondrial permeability transition pore in the gastrocnemius were detected respectively by Western Bloting and fluorescence microscope; the apoptotic cells in atrophic muscle were measured with TUNEL, and the ratio of muscle wet weight was also analyzed for comparison.Results: The ratio of muscle wet weight in group A was 1.029±0.077,and that in group B to E was significantly decreased, it was approximately 1/3 of that in group E after 28 days; The expression of NF-κB p65 in group A was 0.209±0.016, at different time after denervation, the lexels of NF-κB p65 was significantly increased(P <0.01) than group A (normal group); The MPTP fluorescence intensity in group A was 31.574±2.582, and the MPTP fluorescence intensity in group B to E was significantly discreased, it was means that the opening of MPTP was significantly higher than the normal group(P<0.05); The ratio of apoptosis in group A was 4.522±0.946, and the ratio of apoptosis in group B to E were significantly increased compared with that in group A(p <0.05); Furthermore NF-κB p65 had a positive correlation with the opening of MPTP (r=-0.896, P<0.01) and the ratio of apoptosis (r=0.890, P<0.01 ) ,while the increasing of NF-κB p65 and apoptosis was negtively correlation with the ratio of muscle wet weight( P<0.01).Conclusion: NF-κB plays a important role in denervated skeletal muscle atrophy, the effect has a relationship with the opening of MPTP and apoptosis .