PART 1 EXPRESSION OF MMP/TIMP IN SKELETAL MUSCLE OF ARTERIAL OCCLUSION DISEASE MODELS OF DOG’S HIND LIMB  Objective To study the distribution changes of typeⅠand typeⅢcollagen in skeletal muscle of arterial occlusion disease models of dog’s hind limb and the expression of MMP-2/TIMP-2 in skeletal muscle of arterial occlusion disease models of dog’s hind limb. To investigate the significances of collagen metabolism and MMPs in skeletal muscle remodeling due to ischemia.  Methods 12 Healthy dogs. To establish the model of arterial occlusion disease of dog’s hind limb and measure the hind limb skin temperature; meanwhile, to judge whether the models were established successfully by SPECT examination. Every dog was divided into 2 groups: model group(the model place of the left hind limb, M group) and own control group (the right hind limb, OC group). To observe pathological changes of dogs’hind limb skeletal muscles by H.E staining and light microscope; to study the content changes of typeⅠand typeⅢcollagen in dogs’hind limb skeletal muscles at different time points quantitatively