Inhibition of hepatic very—low-density lipoprotein secretion in obese zucker rats adapted to a high-protein diet
| Autor: | Geneviève Griffaton, Athina-Despina Kalopissis, Daniel Fau |
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| Rok vydání: | 1995 |
| Předmět: |
Male
medicine.medical_specialty Very low-density lipoprotein Diet therapy Endocrinology Diabetes and Metabolism medicine.medical_treatment Oleic Acids Lipoproteins VLDL Biology Glucagon chemistry.chemical_compound Endocrinology Internal medicine medicine Animals Insulin Obesity Triglycerides Fatty acid synthesis Triglyceride Body Weight Fatty Acids Hypertriglyceridemia nutritional and metabolic diseases Lipid Metabolism medicine.disease Adaptation Physiological Rats Rats Zucker Lipoproteins LDL Liver chemistry Dietary Proteins Oleic Acid Lipoprotein |
| Zdroj: | Metabolism. 44:19-29 |
| ISSN: | 0026-0495 |
| Popis: | The effect of a high-protein (HP) diet on hepatic very-low-density lipoprotein (VLDL) secretion was studied in obese and lean Zucker rats. With the control (C) diet, isolated hepatocytes from obese as compared with lean rats displayed higher uptake of [1-14C]oleate 0.7 mmol/L, 95% of which was esterified to glycerolipids; greater oleate incorporation into VLDL-triacylglycerol (TG); 2.6 times higher total VLDL-TG secretion; and 11-fold higher de novo fatty acid synthesis. Adaptation to HP feeding decreased weight gains in both phenotypes and hepatocyte TG content in obese rats. Oleate uptake by hepatocytes was appreciably reduced in the obese phenotype only. Despite esterification rates similar to those for the C diet, oleate incorporation into VLDL-TG decreased by 34% and 55% in obese and lean rats, respectively. Total (mass) VLDL-TG secretion was drastically decreased by 65% and 48% in obese and lean rat hepatocytes, respectively. HP feeding combined with overnight fasting accentuated the above decreases. Fatty acid synthesis was 50% lower in cells from HP-fed obese rats, but increased 1.7-fold in lean ones. Plasma glucagon increased in both phenotypes under HP feeding, whereas plasma insulin either increased (obese) or decreased (lean), with the insulin to glucagon ratio slightly decreasing. Thus, HP feeding drastically inhibited hepatic VLDL secretion in obese and lean Zucker rats by an undefined mechanism that was apparently related neither to de novo fatty acid synthesis nor to changes in oleate partitioning between esterification and oxidation. |
| Databáze: | OpenAIRE |
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