Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-18T21:12:08Z No. of bitstreams: 1 DISS_2015_Deise Fátima Mezaroba.pdf: 1567664 bytes, checksum: 67bbe66382033d0b60709a1c450df069 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-27T17:30:42Z (GMT) No. of bitstreams: 1 DISS_2015_Deise Fátima Mezaroba.pdf: 1567664 bytes, checksum: 67bbe66382033d0b60709a1c450df069 (MD5) / Made available in DSpace on 2018-04-27T17:30:42Z (GMT). No. of bitstreams: 1 DISS_2015_Deise Fátima Mezaroba.pdf: 1567664 bytes, checksum: 67bbe66382033d0b60709a1c450df069 (MD5) Previous issue date: 2015-04-30 / CAPES / A dieta hipoproteica-hiperglicídica (LPHC), administrada a ratos machos por 15 ou 45 dias, logo após o desmame, altera vários parâmetros metabólicos e hormonais. Sabe-se também que os hormônios produzidos pela glândula tireoide têm um papel fundamental a nível tecidual para a manutenção da homeostase do organismo. Diante disto, o objetivo deste trabalho foi investigar os efeitos da dieta LPHC a longo prazo e da troca da dieta LHPC por dieta balanceada sobre o metabolismo desiodativo em diferentes tecidos, assim como algumas das ações atribuídas aos hormônios tireóideos. Ratos Wistar machos (~100g) foram randomicamente divididos em grupos conforme segue: 1) controles - alimentados com uma dieta com 17% de proteínas e 63% de carboidratos por 45 dias (C45); 2) LPHC - alimentados com dieta contendo 6% de proteínas e 74% de carboidratos por 45 dias (LPHC45) e; 3) reversão - alimentados por 15 dias com a dieta LPHC e por mais 30 dias com a dieta controle (R) (ANOVA-1 via; p<0,05). A quantificação da concentração do hormônio tireoestimulante no sangue dos animais do grupo R mostrou um aumento de 11,7% e 11,6%, se comparado ao grupo C45 e ao grupo LPHC45, respectivamente (C45: 8439,58 ± 59,46; LPHC45: 8448,06 ± 105,86; R: 9428,39 ± 48,96 pg/mL). A análise da expressão proteica da iodotironina desiodase 1 em fígado, rins e tireoide e da iodotironina desiodase 2 em tecido adiposo marrom, músculos extensor digital longo e sóleo, hipotálamo e hipófise mostrou alteração somente no fígado do grupo LPHC45, com aumento de 17,38% da isoforma 1, em relação aos animais controles. Este grupo também apresentou aumento de 27,02% no conteúdo do receptor hepático para hormônio tireóideo β1, comparando-se ao grupo C45. A avaliação do perfil lipídico de jejum mostrou redução do colesterol total (C45: 97,35 ± 7,87; LPHC45: 65,41 ± 4,78; R: 94,32 ± 5,25 mg/dL), colesterol HDL (C45: 56,58 ± 3,90; LPHC45: 36,74 ± 1,28; R: 54,21 ± xvii 4,30 mg/dL), colesterol VLDL (C45: 22,92 ± 1,44; LPHC45: 15,89 ± 1,50; R: 22,07 ± 1,70 mg/dL) e triglicerídeos (C45: 114,61 ± 7,18; LPHC45: 79,46 ± 7,49; R: 110,36 ± 8,48 mg/dL) nos animais submetidos à dieta LPHC por 45 dias. A expressão hepática da enzima 7α-hidroxilase e da proteína de ligação ao elemento de resposta aos esteróis aumentou 43,96% e 36,27%, respectivamente, no grupo LPHC45, quando comparadas ao grupo C45. A atividade das enzimas málica (C45: 85,92 ± 9,01; LPHC45: 171,63 ± 14,98; R: 159,09 ± 13,16 nmol.mg prot-1.min-1) e ATP-citrato liase (C45: 290,88 ± 11,57; LPHC45: 444,98 ± 20,79; R: 386,75 ± 23,47 nmol.mg prot-1.min-1) foi maior nos grupos LPHC45 e R, em relação ao grupo C45. A análise conjunta destes dados demonstra que a dieta hipoproteica-hiperglicídica administrada por 45 dias leva a alterações no metabolismo desiodativo hepático, modulando o perfil lipídico e que talvez possam resultar em um futuro quadro de esteatose hepática. / The low-protein, high-carbohydrate diet (LPHC) administered to male rats for 15 or 45 days after weaning, change various metabolic and hormonal parameters. It is also known that the hormones produced by the thyroid gland have a key role to tissue level to maintain body’s homeostasis. Thus, the objective of this study was to investigate the effects of the LPHC diet long-term and exchange of LHPC diet for balanced diet on the deiodinative metabolism in different tissues, as well as some of the actions attributed to thyroid hormone. Male Wistar rats (~100g) were randomly divided into the following groups: 1) controls - fed a diet containing 17% protein and 63% carbohydrates for 45 days (C45 group); 2) LPHC - fed a diet containing 6% protein and 74% carbohydrates for 45 days (LPHC45 group), and 3) reversal - fed for 15 days with LPHC diet and for 30 days with the control diet (R group) (ANOVA-one way; p<0.05). The quantification of the concentration of thyroid-stimulating hormone in the blood of the animals of the R group showed an increase of 11.7% and 11.6%, compared with the C45 group and LPHC45 group, respectively (C45: 8439.58 ± 59.46; LPHC45: 8448.06 ± 105.86; R: 9428.39 ± 48.96 pg/mL). Analysis of protein expression of iodothyronine deiodinase 1 in liver, kidney and thyroid, and protein expression of iodothyronine deiodinase 2 in brown adipose tissue, long digital extensor and soleus muscles, hypothalamus, and pituitary only showed alteration in liver of the LPHC45 group, with an increase of 17.38% in the isoform 1, compared with the control animals. This group also showed an increase of 27.02% in the content of liver receptor for thyroid hormone β1 compared with the C45 group. The fasting lipid profile showed a reduction in total cholesterol (C45: 97.35 ± 7.87; LPHC45: 65.41 ± 4.78; R: 94.32 ± 5.25 mg/dL), in HDL cholesterol (C45: 56.58 ± 3.90; LPHC45: 36.74 ± 1.28, R: 54.21 ± 4.30 mg/dL), in VLDL (C45: 22 92 ± 1.44; LPHC45: 15.89 ± 1.50; R: 22.07 ± 1.70 mg/dL), xix and triglycerides (C45: 114.61 ± 7.18; LPHC45: 79.46 ± 7 49; R: 110.36 ± 8.48 mg/dL) in animals subjected to LPHC diet for 45 days. The hepatic expression of 7α-hydroxylase enzyme and the binding protein sterol response element had an increase of 43.96% and 36.27%, respectively, in LPHC45 group when compared with the C45 group. The activity of malic enzyme (C45: 85.92 ± 9.01; LPHC45: 171.63 ± 14.98; R: 159.09 ± 13.16 nmol.mg prot-1 .min-1) and ATP-citrate lyase (C45: 290.88 ± 11.57; LPHC45: 444.98 ± 20.79; R: 386.75 ± 23.47 nmol.mg prot-1 .min-1) was higher in LPHC45 and R groups, compared with C45 group. The analysis of these data shows that the low-protein, high-carbohydrate diet administered for 45 days leads to alterations in hepatic deiodinative metabolism by modulating the lipid profile and that may perhaps result in a future framework of hepatic steatosis.