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A palatable hyperlipidic diet causes obesity and affects brain glucose metabolism in rats.

Estadella D, Oyama LM, Bueno AA, Habitante CA, Souza GI, Ribeiro EB, Motoyama CS, Oller do Nascimento CM - Lipids Health Dis (2011)

Bottom Line: Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups.Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group.The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups.

View Article: PubMed Central - HTML - PubMed

Affiliation: Disciplina de Fisiologia da Nutrição, Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil.

ABSTRACT

Background: We have previously shown that either the continuous intake of a palatable hyperlipidic diet (H) or the alternation of chow (C) and an H diet (CH regimen) induced obesity in rats. Here, we investigated whether the time of the start and duration of these feeding regimens are relevant and whether they affect brain glucose metabolism.

Methods: Male Wistar rats received C, H, or CH diets during various periods of their life spans: days 30-60, days 30-90, or days 60-90. Experiments were performed the 60th or the 90th day of life. Rats were killed by decapitation. The glucose, insulin, leptin plasma concentration, and lipid content of the carcasses were determined. The brain was sliced and incubated with or without insulin for the analysis of glucose uptake, oxidation, and the conversion of [1-14C]-glucose to lipids.

Results: The relative carcass lipid content increased in all of the H and CH groups, and the H30-60 and H30-90 groups had the highest levels. Groups H30-60, H30-90, CH30-60, and CH30-90 exhibited a higher serum glucose level. Serum leptin increased in all H groups and in the CH60-90 and CH30-90 groups. Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups. Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group. The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups.

Conclusion: These findings indicate that both H and CH diet regimens increased body adiposity independent treatment and the age at which treatment was started, whereas these diets caused hyperglycemia and affected brain metabolism when started at an early age.

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Related in: MedlinePlus

Insulin receptor protein (IR) (A. B. and C) and leptin receptor protein (OB-R) (D. E. and F) expression (A.U. - Arbitrary Units) from hypothalamus whole tissue extract. (A. D) groups C30-60. H30-60 and CH30-60; (B. E) groups C60-90. H60-90 and CH60-90 and (C. F) groups C30-90. H30-90 and CH30-90. Values are means ± standard error of the mean of 6 to 7 animals. Values with different superscript letters are significantly different from one another at p < 0.05 (Tukey's test).
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Figure 1: Insulin receptor protein (IR) (A. B. and C) and leptin receptor protein (OB-R) (D. E. and F) expression (A.U. - Arbitrary Units) from hypothalamus whole tissue extract. (A. D) groups C30-60. H30-60 and CH30-60; (B. E) groups C60-90. H60-90 and CH60-90 and (C. F) groups C30-90. H30-90 and CH30-90. Values are means ± standard error of the mean of 6 to 7 animals. Values with different superscript letters are significantly different from one another at p < 0.05 (Tukey's test).

Mentions: (Figure 1A, B and 1C shows the quantification of the insulin receptor (IR) from the extracted tissue of the entire hypothalamus of the rats. The cycled diet from the 30th to 60th day of life significantly decreased the insulin receptor density compared to the C group.


A palatable hyperlipidic diet causes obesity and affects brain glucose metabolism in rats.

Estadella D, Oyama LM, Bueno AA, Habitante CA, Souza GI, Ribeiro EB, Motoyama CS, Oller do Nascimento CM - Lipids Health Dis (2011)

Insulin receptor protein (IR) (A. B. and C) and leptin receptor protein (OB-R) (D. E. and F) expression (A.U. - Arbitrary Units) from hypothalamus whole tissue extract. (A. D) groups C30-60. H30-60 and CH30-60; (B. E) groups C60-90. H60-90 and CH60-90 and (C. F) groups C30-90. H30-90 and CH30-90. Values are means ± standard error of the mean of 6 to 7 animals. Values with different superscript letters are significantly different from one another at p < 0.05 (Tukey's test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3198928&req=5

Figure 1: Insulin receptor protein (IR) (A. B. and C) and leptin receptor protein (OB-R) (D. E. and F) expression (A.U. - Arbitrary Units) from hypothalamus whole tissue extract. (A. D) groups C30-60. H30-60 and CH30-60; (B. E) groups C60-90. H60-90 and CH60-90 and (C. F) groups C30-90. H30-90 and CH30-90. Values are means ± standard error of the mean of 6 to 7 animals. Values with different superscript letters are significantly different from one another at p < 0.05 (Tukey's test).
Mentions: (Figure 1A, B and 1C shows the quantification of the insulin receptor (IR) from the extracted tissue of the entire hypothalamus of the rats. The cycled diet from the 30th to 60th day of life significantly decreased the insulin receptor density compared to the C group.

Bottom Line: Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups.Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group.The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups.

View Article: PubMed Central - HTML - PubMed

Affiliation: Disciplina de Fisiologia da Nutrição, Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil.

ABSTRACT

Background: We have previously shown that either the continuous intake of a palatable hyperlipidic diet (H) or the alternation of chow (C) and an H diet (CH regimen) induced obesity in rats. Here, we investigated whether the time of the start and duration of these feeding regimens are relevant and whether they affect brain glucose metabolism.

Methods: Male Wistar rats received C, H, or CH diets during various periods of their life spans: days 30-60, days 30-90, or days 60-90. Experiments were performed the 60th or the 90th day of life. Rats were killed by decapitation. The glucose, insulin, leptin plasma concentration, and lipid content of the carcasses were determined. The brain was sliced and incubated with or without insulin for the analysis of glucose uptake, oxidation, and the conversion of [1-14C]-glucose to lipids.

Results: The relative carcass lipid content increased in all of the H and CH groups, and the H30-60 and H30-90 groups had the highest levels. Groups H30-60, H30-90, CH30-60, and CH30-90 exhibited a higher serum glucose level. Serum leptin increased in all H groups and in the CH60-90 and CH30-90 groups. Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups. Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group. The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups.

Conclusion: These findings indicate that both H and CH diet regimens increased body adiposity independent treatment and the age at which treatment was started, whereas these diets caused hyperglycemia and affected brain metabolism when started at an early age.

Show MeSH
Related in: MedlinePlus