エンドトキシンおよび亜鉛投与ラットにおける腎メタロチオネインの誘導に関する実験的研究

Metallothionein (MT) induction in the rat kidneys by endotoxin and zinc was investigated at the MT-protein level and the MT-mRNA level. The MT-mRNA level increased 3-6 hr after endotoxin administration, which suggested that MT was not transported from an other organ, but was de novo synthesized. Two MT-protein isoforms, MT-Ⅰ and MT-Ⅱ, were induced by administration of both endotoxin and zinc. The maximum levels of the proteins were seen 9 hr after administration of endotoxin and zinc. The span life of the renal MT induced by zinc was shorter than that of the liver MT induced by zinc. The MT-Ⅱ isoform was predominantly induced by both inducers, endotoxin and zinc, and the ratios of MT-Ⅱ to MT-Ⅰ were relatively constant. The finding that MT-Ⅰ and MT-Ⅱ were almost equally induced by zinc in the liver indicate that MT induction is controlled by an organ-specific system.