Hormonal and Nutritional Regulation of Lipogenic Enzyme mRNA Levels in Rat Primary White and Brown Adipocytes

スポンサーリンク

概要

• 論文の詳細を見る

• Hyroid hormone stimulates hepatic lipogenesis in the rat by increasing the expression of relevant genes, including acetyl-CoA carboxylase and fatty acid synthase. S14 mRNA, which encodes a protein thought to be involved in lipogenesis, responds in parallel. The effects of thyroid hormone on lipogenesis in white and brown adipose tissue are less clear, and may be complicated by indirect effects of the hormone. Rat white and brown preadipocytes were therefore isolated, grown to confluence, and used to test direct effects of thyroid hormone, insulin, and glucose. Lipogenesis was assessed by tritiated water incorporation, and acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and S14 mRNAs were measured by Northern analysis. Insulin (1nM) increased lipogenesis about 9-fold in both white and brown adipocytes. Similar increases were seen in the levels of the three mRNAs. Thyroid hormone (1μM) stimulated lipogenesis and acetyl-CoA carboxylase, fatty acid synthase, and S14 mRNA levels up to 2-fold in both types of adipocyte in the presence or absence of insulin. A high carbohydrate level (25mM glucose) had no effect on lipogenesis compared to a low carbohydrate level (5mM glucose) in white and brown adipocytes. There was no synergistic effect on lipogenesis by the combination of thyroid hormone and high carbohydrate level in both types of adipocytes. These experiments have shown that T3 has small, direct stimulatory effects on lipogenesis in adipocytes. These effects are seen at a pretranslational level, through the coordinate induction of ACC, FAS, and S14 mRNAs. Although lipogenic rates were usually higher in brown adipocytes than white adipocytes, very similar patterns of regulation were seen in the two cell types. These data support the idea that the divergent results seen concerning T3 regulation of the lipogenic pathway in both brown and white adipose tissue in vivo arise from secondary effects of the alteration of thyroid status.

• 財団法人 学会誌刊行センターの論文

著者

• Moon Yangha

  Department Of Food And Nutrition Ewha Womans University

• Freake Hedley

  Department Of Nutritional Sciences University Of Connecticut

関連論文

• Hormones and Nutrients Regulate Acetyl-CoA Carboxylase Promoter I in Rat Primary Hepatocytes
• Barley β-Glucan Lowers Serum Cholesterol Based on the Up-Regulation of Cholesterol 7α-Hydroxylase Activity and mRNA Abundance in Cholesterol-Fed Rats
• Hormonal and Nutritional Regulation of Lipogenic Enzyme mRNA Levels in Rat Primary White and Brown Adipocytes
• Barley β-Glucan Lowers Serum Cholesterol Based on the Up-Regulation of Cholesterol 7α-Hydroxylase Activity and mRNA Abundance in Cholesterol-Fed Rats
• Hormonal and Nutritional Regulation of Lipogenic Enzyme mRNA Levels in Rat Primary White and Brown Adipocytes

スポンサーリンク