| Objective:to study the expression of IGF-1, Bel-2, Bax, and Caspase-3,some of which are cell apoptosis related protease, in rats with Chronic obstructive pulmonary disease.And explore whether the reduced expression of IGF-1in rats with COPD affects the ratio of Bcl-2/Bax.Then it leads to activation of Caspase-3protein.As a result, skeletal muscle atrophy appears.Meathod:Seventy healthy male adult wistar rats were randomly divided into two groups:a normal control group(n=35) and a model group (n=35). The COPD model rats were exposed to cigarattes smoking for104days and injected into Trypsin(PPE) through trachea in the15th day. The normal control group were injected Saline in the same day.Two groups of rats were kept to the104th days.In the104th days the lung tissue and extensor digitorum longus were got from the rats.One of extensor digitorum longu were made into paraffin sections,the other one were kept into-80°C refrigerator, prefaring for the Western-Blot. The serum were got from the arterial extraction of the rats.At the same time we measured the weight of the body and the extensor digitorum longus of the two groups of the rats. HE staining was used to observe the changes in the structμre of two groups of rat lung tissue Immunohistochemical method were used to determine the expression of IGF-1, Bcl-2, Bax and Caspase-3in the the extensor digitorum longus. ELISA (enzyme-linked immunosorbent assay) was used to determine the expression of serum IGF. Image-Pro Plus Version6.0image processing system were used to determine the intensity of immμnohistochemical results. Werstern-Blot was used to determine the expression of Caspase-3activity protein in the extensor digitorμm longus of the rats. The data obtained was tested by by SPSS17.0software single factor analysis of variance, t test and correlation analysis.Results:1. The wall of the airway and lμng tissue of COPD model group rats were infiltrted with inflammatory cells.The diagnosis of COPD was measμred by the lung function of the rats and observation of lung tissue biopsy.2. the body weight (328.41±8.91) and the weight of one side of the extensordigitorμm longus (158.4±4.2) of the COPD model group rats, compared with normal control rats, body weight (371.84±7.61) as well as the weight of the extensor digitorum longus (179.3±3.8) have significantly reduced (P<0.05, P<0.05)3. serum IGF-1concentration (10.23±0.518in) and expression of IGF-1(123.41±10.23) of extensor digitorμm longus, in the COPD model group rats was significantly lower than the serum IGF-1concentration (12.35±0.499) and the expression of IGF-1(184.23±9.48)of the extensor digitorum longus in the control group rats,(P<0.05, P<0.05).4. The expression of Bcl-2(114.09±8.43) in the normal control group rats was significantly stronger than the expression of the COPD model group rats (181.49±9.31)(P<0.05, P<0.05).5.The expression of Bax in the COPD model group rats (64.32±3.04) was significantly stronger than the expressionin the control rats (35.48±2.88)(P<0.05, P<0.05).6.The expression of Caspase-3in the extensor digitorμm longus of the COPD model group rats (63.37±7.23,0.4558±0.0443) was significantly stronger than the expression in the control group (38.39±6.78,0.1776±0.0445)(P<0.05, P<0.05).7. The expression of IGF-1in the serμm and the extensor digitorμm longus was positively correlated with the ratio of Bcl-2/Bax by the Correlation Analysis.8. The expression of IGF-1in the serμm and the extensor digitorμm longus was positively correlated with expression of Caspase-3by the Correlation Analysis.Conclusion: 1. The expression of IGF-1of the serum and skeletal muscle in the COPD model group rats were significantly reduced.2. The increment of the apoptosis in skeletal muscle may be an important mechanism of skeletal muscle atrophy of the COPD model rats.3. In the COPD model rats, the reduction of expression of IGF-1may affect the Bcl-2/Bax ratio, and thμs activated Caspase-3protein, resulting in the apoptosis cascade reaction, eventually leading to skeletal muscle atrophy... |
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