The Study On Proton Leak And Uncoupling Protein Of Tree Shrew

The article is beginning from the effects of cold exposure on thermogenesis of mitchondrial proton leak of tree shrew, then tries to explain the mechanism of mitchondrial thermogenesis and the relationship between UCPs and the thermogenesis.This thesis is consists of four parts:1. The effects of cold exposure on mitochondrial respiration of diaphragm and cardiac muscle in tree shrews.2. The effects of cold exposure on mitochondrial respiration of liver in tree shrews.3. The effects of cold exposure on expression of UCP1 in liver and the sequence-testing of UCP1 in liver.4. The effects of cold exposure on expression of UCP1 in BAT of tree shrew.The results and conclusions:1. In mammals acutely exposed to cold (1h, 4h, 8h), the state IV mitochondrial respiration of diaphragm in the 8h group is more enhanced than the control, the state IV mitochondrial respiration of cardiac muscle in the 4h and 8h group are more enhanced than the control; With time in cold (1d, 7d, 14d, 28d), the state IV mitochondrial respiration of diaphragm and cardiac muscle are more enhanced than the control, the 28d group is more markedly than others. The changes will be benefit for the study on the character mitochondrial proton leak thermogenesis of diaphragm and cardiac muscle in tree shrews during the cold expose.2. we had measured the mitochondrial respiration of the III state and the IV state of the liver in the tree shrews, which had been exposured under cold surroundingtemperature during acutely exposed cold (1h, 4h, 8h)and cold time (ld,7d,14d,28d). The changes of the mitochondrial respiration of the III state , the mitochondrial respiration of the IV state and the content of mitochondrial protein are turned down little first then turned up gradually later.It suggested that the liver of tree shrews maybe have some proton leak thermogenesis.3. We found the UCP1 mRNA in liver of tree shrew by RT-PCR, and both the content of total RNA in liver and the expression of UCP1 were increased. This results maybe suggest the existing of UCP1 in liver of tree shrew and the expression of UCP1 is sensitive to cold exposure.4. With the half quantitative RT-PCR, we found the expression of UCP1 in BAT was increased compared with the control experiment, the increase was 131.92%.Which maybe suggest cold exposure was the more effective factor to the expression of UCP1.Conclusion:In a word, during the whole cold exposure, the mitochondrial respiration of the IV state of cardiac muscle diaphragm and liver were all increased markedly, but this change were different with the north minitype mammal. The RT-PCR product was the sequence of UCP1, and the cold exposure made the content of expression of UCP1 in liver increase markedly. In addition, the content of the expression of UCP1 mRNA was increased markedly after cold exposure.These suggest the exiting of proton leak thermogenesis in cardiac muscle diaphragm and liver, while the mechanism maybe correlate with the UCPs. And we could confirm that cold exposure make the expression of UCP1 in BAT increased. While the thermogenesis of liver and musle were both increased, which were different with the north minitype mammal, which maybe correlate with the living entironment of tree shrew.