Metallothionein protects rat hepatic nuclear nucleoside triphosphatase from hydroxyl radical-induced suppression / 中国病理生理杂志

ABSTRACT

AIM: Metallothioneins (MTs) are cysteine-rich metal-binding proteins that exert cytoprotection during metal exposure and oxidative stress. The present study was designed to investigate whether MT can directly protect NTPase on nuclear envelope from damage induced by hydroxyl radical.METHODS: Isolated hepatic nuclei from rat liver were exposed to Fe 2+ /H 2O 2 with or without MT, and the NTPase activity on nuclei was assayed using ATP and GTP as substrate, respectively. RESULTS: Incubation of rat hepatic nuclei with the Fe 2+ /H 2O 2 (in ?mol?L -1 / ?mol?L -1 0 1/0 5, 0 5/2 5, 1/5, 5/25) resulted in a concentration-dependent decrease in nuclear NTPase activities ( P0 05 ). In addition, incubation of hepatic nuclei with only MT had no effect on nuclear NTPase activity. CONCLUSION: These data demonstrate that hydroxyl radical generated from Fe 2+ /H 2O 2 might attack nuclear NTPase. MT antagonistically reduces toxicity of Fe 2+ /H 2O 2 system to the NTPase.