Dietary Protein Restriction Alters Lipid Metabolism and Insulin Sensitivity in Rats
2
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
Dietary protein restriction affects lipid metabolism in rats. This study was performed to determine the effect of a low protein diet on hepatic lipid metabolism and insulin sensitivity in growing male rats. Growing rats were fed either a control 20% protein diet or an 8% low protein diet. Feeding a low protein diet for four weeks from 8 weeks of age induced a fatty liver. Expression of acetyl-CoA carboxylase, a key lipogenic enzyme, was increased in rats fed a low protein diet. Feeding a low protein diet decreased very low density lipoprotein (VLDL) secretion without statistical significance. Feeding a low protein diet down-regulated protein expression of microsomal triglyceride transfer protein, an important enzyme of VLDL secretion. Feeding a low protein diet increased serum adiponectin levels. We performed glucose tolerance test (GTT) and insulin tolerance test (ITT). Both GTT and ITT were increased in protein-restricted growing rats. Our results demonstrate that dietary protein restriction increases insulin sensitivity and that this could be due to low-protein diet-mediated metabolic adaptation. In addition, increased adiponectin levels may influences insulin sensitivity. In conclusion, dietary protein restriction induces a fatty liver. Both increased lipogenesis and decreased VLDL secretion has contributed to this metabolic changes. In addition, insulin resistance was not associated with fatty liver induced by protein restriction.
Abstract
Dietary protein restriction affects lipid metabolism in rats. This study was performed to determine the effect of a low protein diet on hepatic lipid metabolism and insulin sensitivity in growing male rats. Growing rats were fed either a control 20% protein diet or an 8% low protein diet. Feeding a low protein diet for four weeks from 8 weeks of age induced a fatty liver. Expression of acetyl-CoA carboxylase, a key lipogenic enzyme, was increased in rats fed a low protein diet. Feeding a low protein diet decreased very low density lipoprotein (VLDL) secretion without statistical significance. Feeding a low protein diet down-regulated protein expression of microsomal triglyceride transfer protein, an important enzyme of VLDL secretion. Feeding a low protein diet increased serum adiponectin levels. We performed glucose tolerance test (GTT) and insulin tolerance test (ITT). Both GTT and ITT were increased in protein-restricted growing rats. Our results demonstrate that dietary protein restriction increases insulin sensitivity and that this could be due to low-protein diet-mediated metabolic adaptation. In addition, increased adiponectin levels may influences insulin sensitivity. In conclusion, dietary protein restriction induces a fatty liver. Both increased lipogenesis and decreased VLDL secretion has contributed to this metabolic changes. In addition, insulin resistance was not associated with fatty liver induced by protein restriction.
참고문헌 (28)
- Aparecida de Franca, S, "Low protein diet changes the energetic balance and sympathetic activity in brown adipose tissue of growing rats", Nutrition, 25, pp.1186~1192 (2009)
- Ascaso, J. F, "Advances in cholesterol-lowering interventions", Endocrinol. Nutr, 57, pp.210~219 (2010)
- Atkinson, L. L, "MEDICA 16 inhibits hepatic acetyl-CoA carboxylase and reduces plasma triacylglycerol levels in insulin-resistant JCR: LA-cp rats", Diabetes, 51, pp.1548~1555 (2002)
- Begriche, K., "Mitochondrial dysfunction in NASH: causes, consequences and possible means to prevent it", Mitochondrion, 6, pp.1~28 (2006)
- Cano, A., "Hepatic VLDL assembly is disturbed in a rat model of nonalcoholic fatty liver disease: is there a role for dietary coenzyme Q", J. Appl. Physiol, 107, pp.707~717 (2009)
- Chang, B. H, "Liver-specific inactivation of the abetalipoproteinemia gene completely abrogates very low density lipoprotein", low density lipoprotein production in a viable conditional knockout mouse, 1999, pp.274, 6051~6055
- del Rincon, J. P, "Growth hormone regulation of p85alpha expression and phosphoinositide 3-kinase activity in adipose tissue: mechanism for growth hormone-mediated insulin resistance", Diabetes, 56, pp.1638~1646 (2007)
- Fiaschi, T, "Redox-dependent and ligand-independent trans-activation of insulin receptor by globular adiponectin", Hepatology, 46, pp.130~139 (2007)
- Folch, J., "A simple method for the isolation and purification of total lipids from animal tissues", J. Biol. Chem, 226, pp.497~509 (1957)
- Fujita, K., "Dysfunctional very-low-density lipoprotein synthesis and release is a key factor in nonalcoholic steatohepatitis pathogenesis", Hepatology, 50, pp.772~780 (2009)
- Ikejima, K., "Role of adipocytokines in hepatic fibrogenesis. J. Gastroenterol", Hepatol, 1, pp.87~92 (2007)
- Kim, J. Y, "Obesity-associated improvements in metabolic profile through expansion of adipose tissue", J. Clin. Invest, 117, pp.2621~2637 (2007)
- Marchesini, G, "NASH: from liver diseases to metabolic disorders and back to clinical hepatology", Hepatology, 35, pp.497~499 (2002)
- Marra, F, "Adipokines in liver diseases", Hepatology, 50, pp.957~969 (2009)
- Minehira, K, "Blocking VLDL secretion causes hepatic steatosis but does not affect peripheral lipid stores or insulin sensitivity in mice", J. Lipid Res, 49, pp.2038~2044 (2008)
- Morris, L, "Fatty livers in weanling rats fed a low protein, threonine-deficient diet. I. Effect of various diet fats", J. Nutr, 85, pp.362~366 (1965)
- Postic, C, "The role of the lipogenic pathway in the development of hepatic steatosis", Diabetes Metab, 34, pp.643~648 (2008)
- Rothwell, N. J, "Mechanisms of thermogenesis induced by low protein diets", Metabolism, 32, pp.257~261 (1983)
- Singal, S. A, "The production of fatty livers in rats on threonine-and lysine-deficient diets", J. Biol. Chem, 200, pp.867~874 (1953)
- Therond, P, "Catabolism of lipoproteins and metabolic syndrome", Curr. Opin. Clin. Nutr. Metab. Care, 12, pp.366~371 (2009)
- Theys, N, "Maternal low-protein diet alters pancreatic islet mitochondrial function in a sex-specific manner in the adult rat", Am. J. Physiol. Regul. Integr. Comp. Physiol, 297, pp.1516~1525 (2009)
- Thonney, M. L, "Composition of gain of rats fed low or high protein diets and grown at controlled rates from 80 to 205 grams", J. Nutr, 117, pp.2135~2141 (1987)
- Tilg, H, "Nonalcoholic fatty liver disease: Cytokine-adipokine interplay and regulation of insulin resistance", Gastroenterology, 131, pp.934~945 (2006)
- White, B. D., "Low protein diets increase neuropeptide Y gene expression in the basomedial hypothalamus of rats", J. Nutr, 124, pp.1152~1160 (1994)
- White, B. D, "Effects of age on the feeding response to moderately low dietary protein in rats", Physiol. Behav, 68, pp.673~681 (2000)
- White, B. D., "Protein selection, food intake, and body composition in response to the amount of dietary protein", Physiol. Behav, 69, pp.383~598 (2000)
- Yamaguchi, K, "Inhibiting triglyceride synthesis improves hepatic steatosis but exacerbates liver damage and fibrosis in obese mice with nonalcoholic steatohepatitis", Hepatology, 45, pp.1366~1374 (2007)
- Xiaogang Yan, "Effects of Chromium on Energy Metabolism in Lambs Fed with Different Dietary Protein Levels", ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES, 23(2), pp.205~212 (2010), 아세아·태평양축산학회