The Role of P38 & ERK in Apoptosis of Skeletal Muscle of Chronic Hypoxia-hypercapnia Mice

Abstract: To investigate the role of P38 and ERK in apoptosis of skeletal muscle of chronic hypoxiahypercapnia mice. The hypoxia hypercapnia group mice were placed in a sealed chamber， where O2 concentration maintained at 9%~11%， and CO2 concentration maintained at 5%~6%， for 8 hours a day， 6 days a week， 4 weeks. The weight of mice was weighted. The cell morphology and the mitochondrial structure of skeletal muscle were observed. The content of Cytochrome C and apoptosis-inducing factor in the mitochondria and in the cytoplasm was determined. The expression of Bad mRNA， Bcl-xl mRNA， p-P38 protein and p-ERK protein was detected. The results showed that the HH group mice had lost weight. There was fibers fracture and fat deposition in the HH group mice. The mitochondrial membrane was partially destroyed， and the cristae was disorganized. The content of Cyt C and AIF in the mitochondria was reduced， while the content of Cyt C and AIF in the cytoplasm was increased. The expression of Bad mRNA was increased， while the expresson of Bcl-xl mRNA was decreased. The expression of p-P38 protein and p-ERK protein was increased. Thus， apoptosis of skeletal muscle of mice was induced by chronic hypoxic hypercapnia. P38 and ERK signaling pathway might be in the process of apoptosis， by activating the Bad， inhibiting the Bcl-xl and promoting Cyt C and AIF releasing into the cytoplasm.

CSTR: 32200.14.cjcb.2013.04.0006