High-fat diets rich in soy or fish oil distinctly alter hypothalamic insulin signaling in rats
| Autor: | Aparecida Emiko Hirata, Gustavo D. Pimentel, Gabriel Inácio de Morais Honorato de Souza, Regina Lúcia Harumi Watanabe, Valter Tadeu Boldarine, Cláudio A. Cunha, Eliane Beraldi Ribeiro, Fábio Santos Lira, Lila Missae Oyama, Ana P. S. Dornellas, José C. Rosa, Claudia Maria Oller do Nascimento |
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| Rok vydání: | 2012 |
| Předmět: |
Leptin
Male medicine.medical_specialty Endocrinology Diabetes and Metabolism medicine.medical_treatment Clinical Biochemistry Hypothalamus Adipose tissue Diet High-Fat Weight Gain Biochemistry Fat pad Fish Oils Insulin resistance Internal medicine medicine Animals Insulin Phosphorylation Rats Wistar Molecular Biology Nutrition and Dietetics biology Chemistry Fish oil medicine.disease Dietary Fats Rats Soybean Oil Insulin receptor Endocrinology Adipose Tissue biology.protein Soybeans Insulin Resistance medicine.symptom Energy Intake Weight gain Signal Transduction |
| Zdroj: | The Journal of Nutritional Biochemistry. 23:822-828 |
| ISSN: | 0955-2863 |
| Popis: | Hypothalamic insulin inhibits food intake, preventing obesity. High-fat feeding with polyunsaturated fats may be obesogenic, but their effect on insulin action has not been elucidated. The present study evaluated insulin hypophagia and hypothalamic signaling after central injection in rats fed either control diet (15% energy from fat) or high-fat diets (50% energy from fat) enriched with either soy or fish oil. Soy rats had increased fat pad weight and serum leptin with normal body weight, serum lipid profile and peripheral insulin sensitivity. Fish rats had decreased body and fat pad weight, low leptin and corticosterone levels, and improved serum lipid profile. A 20-mU dose of intracerebroventricular (ICV) insulin inhibited food intake in control and fish groups, but failed to do so in the soy group. Hypothalamic protein levels of IR, IRS-1, IRS-2, Akt, mTOR, p70S6K and AMPK were similar among groups. ICV insulin stimulated IR tyrosine phosphorylation in control (68%), soy (36%) and fish (34%) groups. Tyrosine phosphorylation of the pp185 band was significantly stimulated in control (78%) and soy (53%) rats, but not in fish rats. IRS-1 phosphorylation was stimulated only in control rats (94%). Akt serine phosphorylation was significantly stimulated only in control (90%) and fish (78%) rats. The results showed that, rather than the energy density, the fat type was a relevant aspect of high-fat feeding, since blockade of hypothalamic insulin signal transmission and insulin hypophagia was promoted only by the high-fat soy diet, while they were preserved in the rats fed with the high-fat fish diet. |
| Databáze: | OpenAIRE |
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