RESUMO
Ischemic-reperfusion injury of skeletal muscles takes place in the phase of reperfusion and induces cellular damages through activating various transcription factors and genes, which initiate signal transduction. The purpose of this study was to observe changes of expression of NF-kappa B and AP-1, which are known as a redox sensitive transcription factors in ischemic-reperfused rat skeletal muscles, and PKC theta which activate NF-kappa B and AP-1. Sprague-Dawley male rats of nine, thirty, and sixty-five weeks old were divided into control and ischemia groups. Ischemia was performed by occlusion of left common iliac artery for 4 hours using rodent vascular clamps. The animals were sacrificed at hours 0, 1, 3 and 6 after onset of reperfusion and tibialis anterior and soleus muscles were removed. The distributions of PKC theta, NF-kappa B, and AP-1 immunoreactivity (IMR) were examined using immunohistochemical methods. The results as follows; In control groups, PKC theta IMR was decreased with age and was higher in tibialis anterior than that in soleus muscles. In ischemia groups, PKC theta IMR was increased with age and was higher in soleus than that in tibialis anterior muscles. In control groups, NF-kappa B IMR was decreased with age. In ischemia groups, NF-kappa B IMR was increased with age and was higher in soleus than that in tibialis anterior muscles. In control groups, AP-1 IMR was decreased with age. In ischemia groups, AP-1 IMR was increased with age and was higher in tibialis anterior than that in soleus muscles. Increase or decrease of PKC theta IMR was associated with the increase or decrease of NF-kappa B and AP-1 IMR in ischemic-reperfused rat skeletal muscles, respectively. These results suggested that the increased expression of PKC theta may induce the upregulations of NF-kappa B and AP-1 in ischemic-reperfusion injury of rat skeletal muscle. It is also suggested that the ischemic injury may be increased with age, and tibialis anterior muscle is more susceptabile to ischemic-reperfusion injury than soleus muscle.