Yang J, Cherian M G
Department of Pathology, University of Western Ontario, London, Canada.
Life Sci. 1994;55(1):43-51. doi: 10.1016/0024-3205(94)90080-9.
The protective roles of metallothionein (MT) in streptozotocin (STZ)-induced pancreatic damage were investigated using zinc (Zn) as the inducer of MT synthesis in rats. Diabetes was produced in a group of Sprague Dawley rats by a single injection of STZ. In another group of rats, to induce the synthesis of MT, Zn was injected subcutaneously about 12 h before injection of STZ. Rats were sacrificed at about 30 h, 3 and 6 weeks after administration of STZ. The plasma glucose levels in STZ and Zn+STZ group increased significantly in 30 h, 3 and 6 weeks compared with the control group, but the level of glucose in Zn+STZ group was lower than that in the STZ group. Both Zn and MT levels increased in pancreas, liver, and kidney of rats injected with Zn or Zn+STZ. The induction of MT synthesis in pancreas of Zn-injected rats was also demonstrated by Western Blot analysis. Lipid peroxidation induced by STZ was inhibited significantly by pretreatment with Zn. Injection of STZ decreased the activities of superoxide dismutase (SOD) in plasma, liver and pancreas, but injection of Zn had no effect on the activities of SOD. The results support that pretreatment with Zn can partially prevent the development of diabetes induced by STZ injection and it may be related to the effects of MT as a scavenger for the oxygen free radicals.
以锌（Zn）作为大鼠金属硫蛋白（MT）合成的诱导剂，研究了MT在链脲佐菌素（STZ）诱导的胰腺损伤中的保护作用。通过单次注射STZ使一组Sprague Dawley大鼠患糖尿病。在另一组大鼠中，在注射STZ前约12小时皮下注射Zn以诱导MT合成。在给予STZ后约30小时、3周和6周处死大鼠。与对照组相比，STZ组和Zn + STZ组的血浆葡萄糖水平在30小时、3周和6周时显著升高，但Zn + STZ组的葡萄糖水平低于STZ组。注射Zn或Zn + STZ的大鼠胰腺、肝脏和肾脏中的Zn和MT水平均升高。Western Blot分析也证实了注射Zn的大鼠胰腺中MT合成的诱导。Zn预处理可显著抑制STZ诱导的脂质过氧化。注射STZ会降低血浆、肝脏和胰腺中超氧化物歧化酶（SOD）的活性，但注射Zn对SOD的活性没有影响。结果表明，Zn预处理可部分预防STZ注射诱导的糖尿病的发展，这可能与MT作为氧自由基清除剂的作用有关。
