당뇨병 백서의 간세포에서 Glucokinase 활성도 및 유전자 발현에 대한 인슐린의 영향 = Regulation of Glucokinase Gene Expression and Activity in the Liver of Diabetic Rats

다국어 초록 (Multilingual Abstract)

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다국어 초록 (Multilingual Abstract)

Introduction: The liver-specific hexokinase isoenzyme, referred to as glucokinase, is thought to play a key reglulatory role in hepatic glucose metabolism. The glucokinase gene is, therefore, of interest both because of its tissue-specific expression and because of the several regulatory processes that can be analyzed. The level of hepatic glucokinase activity appers to be determined essentially by regulation of the rate of enzyme sythesis, with insulin playing a leading role as an inducer. We investigated the role of insulin for the induction of glucokinase in the liver of diabetic rats. Methods: Experimental diabetes was induced by injection of streptozotocin 7 days before the experiment. Regular insulin was given by three days intraperitoneal injection at 8-h interval. The glucokinase mRNA in the liver was estimated by Nothern blot assay, as well as by fluorometric enzyme activity assay. Results: Glucokinase activity was not reduced in the liver of normal fasting rats as compared to normal fed rats. But glucokinase activity was recuced in the liver of daibetic rats as compared to normal rats. In diabetic rats treated with insulin, glucokinase enzyme activity were increased. But glucokinase mRNA expression was only increased in normogycemic diabetic rat with treated with insulin as compared to hyperglycemic rat. Conclusion: These data indicate that insulin stimulates hepatic glucokinase enzyme activity and mRNA expression. But other hormonal or metabolic factors may be contribute to regulation of glucokinase mRNA expressiom.