| Research Abstract |
Recent studies show that there is a close relationship between reactive oxygen species and man diseases.
In the first year, we synthesized ^<35>S-labeled RNA probe from cDNA of human Cu/Zn-type superoxide dismutase(SOD), which degrades reactive oxygen species and investigated the expression of SOD in normal rat tissues by in situ hybridization(ISH). In addition, ISH using nonradioactive probes was examined. As a resuly, the signals showing the presence of SOD mRNA were found in hippocampus, Purkinje's cells incerebellum, hepatocytes and epithelial cells of the bronchioles. Eosinophils also showed strong signals. This is interesting finding because, eosinophils are potent producer of active oxygen species. Nonradioactive RNA probes were synthesized in the presence of digoxigenin(DIG)-UTP and were visualized with anti-DIG-alkaline phosphatase conjugate and alkaline phosphatase reaction. Weak signals of SOD mRNA were detected in the isolated eosinophils while the sigals of actin mRNA were detected under electron microscopy by nonradioactive ISH.
In the last year, the expression of SOD mRNA was examined under pathological consitions. First, we tested the effect of a SOD derivative(SM-SOD)on liver injury caused by ischemia and repurfusion under electron microscopy. Postischemic reperfusion caused a drastic change in liver morphology, and intravenous administration of SM-SOD completely inhibited these morphological changes. But, the expression of endogeneous SOD in hepatocytes under these conditions was not marked. Secondly, we tested the exppession of SOD in rat lung after prolonged oxygen inhalation which caused lethal lung edema. The expression of SOD is not marked. It may be necessary to study the change of the expression of Mn type SOD.
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