RESUMO
In experimental studies, several parameters, such as body weight, body mass index, adiposity index, and dual-energy X-ray absorptiometry, have commonly been used to demonstrate increased adiposity and investigate the mechanisms underlying obesity and sedentary lifestyles. However, these investigations have not classified the degree of adiposity nor defined adiposity categories for rats, such as normal, overweight, and obese. The aim of the study was to characterize the degree of adiposity in rats fed a high-fat diet using cluster analysis and to create adiposity intervals in an experimental model of obesity. Thirty-day-old male Wistar rats were fed a normal (n=41) or a high-fat (n=43) diet for 15 weeks. Obesity was defined based on the adiposity index; and the degree of adiposity was evaluated using cluster analysis. Cluster analysis allowed the rats to be classified into two groups (overweight and obese). The obese group displayed significantly higher total body fat and a higher adiposity index compared with those of the overweight group. No differences in systolic blood pressure or nonesterified fatty acid, glucose, total cholesterol, or triglyceride levels were observed between the obese and overweight groups. The adiposity index of the obese group was positively correlated with final body weight, total body fat, and leptin levels. Despite the classification of sedentary rats into overweight and obese groups, it was not possible to identify differences in the comorbidities between the two groups.
Assuntos
Adiposidade/fisiologia , Modelos Animais de Doenças , Obesidade/classificação , Comportamento Sedentário , Animais , Glicemia/análise , Pressão Sanguínea , Peso Corporal , Colesterol/sangue , Análise por Conglomerados , Dieta Hiperlipídica , Ácidos Graxos não Esterificados/sangue , Insulina/sangue , Leptina/sangue , Masculino , Ratos Wistar , Índice de Gravidade de Doença , Fatores de Tempo , Triglicerídeos/sangueRESUMO
In experimental studies, several parameters, such as body weight, body mass index, adiposity index, and dual-energy X-ray absorptiometry, have commonly been used to demonstrate increased adiposity and investigate the mechanisms underlying obesity and sedentary lifestyles. However, these investigations have not classified the degree of adiposity nor defined adiposity categories for rats, such as normal, overweight, and obese. The aim of the study was to characterize the degree of adiposity in rats fed a high-fat diet using cluster analysis and to create adiposity intervals in an experimental model of obesity. Thirty-day-old male Wistar rats were fed a normal (n=41) or a high-fat (n=43) diet for 15 weeks. Obesity was defined based on the adiposity index; and the degree of adiposity was evaluated using cluster analysis. Cluster analysis allowed the rats to be classified into two groups (overweight and obese). The obese group displayed significantly higher total body fat and a higher adiposity index compared with those of the overweight group. No differences in systolic blood pressure or nonesterified fatty acid, glucose, total cholesterol, or triglyceride levels were observed between the obese and overweight groups. The adiposity index of the obese group was positively correlated with final body weight, total body fat, and leptin levels. Despite the classification of sedentary rats into overweight and obese groups, it was not possible to identify differences in the comorbidities between the two groups.
Assuntos
Animais , Masculino , Adiposidade/fisiologia , Modelos Animais de Doenças , Obesidade/classificação , Comportamento Sedentário , Glicemia/análise , Pressão Sanguínea , Peso Corporal , Colesterol/sangue , Análise por Conglomerados , Dieta Hiperlipídica , Ácidos Graxos não Esterificados/sangue , Insulina/sangue , Leptina/sangue , Ratos Wistar , Índice de Gravidade de Doença , Fatores de Tempo , Triglicerídeos/sangueRESUMO
AIM: To investigate whether lycopene can modulate adiponectin levels and SIRT1 and FoxO1 gene expression in the adipose tissue of diet-induced obese rats. METHODS: Male Wistar rats were first fed with hypercaloric diet (HD, n = 12) for 6 weeks, and afterward, these rats were randomly assigned to receive HD (n = 6) or HD with lycopene-rich tomato oleoresin (equivalent to lycopene 10 mg/kg body weight (BW)/day, HD + L, n = 6) by gavage for additional 6 weeks. Plasma lycopene and adiponectin levels were analyzed by high-performance liquid chromatography and immunoassay, respectively. The messenger RNA (mRNA) expressions of adiponectin, Sirtuin 1 (SIRT1), Forkhead box O 1 (FoxO1), fatty acid translocase/cluster of differentiation 36 (FAT/CD36), and PPARγ in adipose tissues were determined by quantitative polymerase chain reaction. RESULTS: Lycopene was detected in the plasma of rats in HD + L group but not in the HD group. Although both BW and adiposity were not different between the two groups, there was a significant increase in both plasma concentration and mRNA expression of adiponectin in the adipose tissue of the HD + L group. In addition, the lycopene supplementation upregulated mRNA expressions of SIRT1, FoxO1, and FAT/CD36 but downregulated PPARγ in adipose tissue of obese rats. CONCLUSION: These data suggest that lycopene, in the concentration used, is not toxic and also its health benefits in adipose tissue may play a role against obesity-related complications.
Assuntos
Tecido Adiposo/efeitos dos fármacos , Carotenoides/farmacologia , Obesidade/metabolismo , Extratos Vegetais/farmacologia , Solanum lycopersicum , Adiponectina/sangue , Adiponectina/genética , Tecido Adiposo/metabolismo , Animais , Carotenoides/sangue , Carotenoides/farmacocinética , Fatores de Transcrição Forkhead/genética , Licopeno , Masculino , Proteínas do Tecido Nervoso/genética , Obesidade/sangue , PPAR gama/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Sirtuína 1/genéticaRESUMO
Thyroid hormones regulate energy balance and act on adipokines. However, while it is unclear what the effects are of calorie restriction and high doses of triiodothyronine (T(3)) on adipokines in obesity, thyroid hormones are illicitly administered in isolation or in association with a hypocaloric diet as an obesity treatment. The present study determined the effect of T(3) on serum concentrations and gene expression of the adipokines leptin, resistin, and adiponectin in calorie-restricted obese rats. Male Wistar rats received a hypercaloric diet for 20 weeks followed by calorie restriction for 8 weeks. The animals were then randomly divided into 3 groups: calorie restriction (OR), OR with 5 µg of T(3)/100 g BW (RS1), and OR with 25 µg of T(3)/100 g BW (RS2) for 2 weeks. Blood and adipose tissue samples were collected for biochemical, hormonal, and gene expression analyses. Serum concentrations of leptin (OR: 3.7±0.6, RS1: 3.8±1, RS2 0.2±0.07 ng/dl) and resistin (OR: 2.5±0.6, RS1: 2.5±0.5, RS2 1.6±0.3 ng/dl) were diminished at the higher dose, while serum adiponectin (OR: 31±7, RS1: 24±5, RS2 26±7 ng/dl) levels were lower in the low dose group. Administration of T(3) reduced leptin gene expression (OR: 0.91±0.1, RS1: 0.95±0.1, RS2 0.22±0.1) only at the higher dose, resistin expression (OR: 1.06±0.2, RS1: 1.04±0.1, RS2 0.88±0.2) was not influenced by T(3) treatment, and adiponectin expression (OR: 1.55±0.5, RS1: 0.95±0.15, RS2 0.97±0.13) was diminished independent of the T(3) dose. These results indicate that T(3), directly or indirectly, inhibits the expression of leptin and adiponectin in calorie restricted obese animals.
Assuntos
Adiponectina/genética , Restrição Calórica , Regulação da Expressão Gênica/efeitos dos fármacos , Leptina/genética , Obesidade/genética , Resistina/genética , Tri-Iodotironina/farmacologia , Adiponectina/sangue , Tecido Adiposo/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/genética , Relação Dose-Resposta a Droga , Leptina/sangue , Masculino , Obesidade/sangue , Ratos , Ratos Wistar , Resistina/sangue , Tri-Iodotironina/administração & dosagemRESUMO
Obesity is a complex multifactorial disorder that is often associated with cardiovascular diseases. Research on experimental models has suggested that cardiac dysfunction in obesity might be related to alterations in myocardial intracellular calcium (Ca2+) handling. However, information about the expression of Ca2+-related genes that lead to this abnormality is scarce. We evaluated the effects of obesity induced by a high-fat diet in the expression of Ca2+-related genes, focusing the L-type Ca2+ channel (Cacna1c), sarcolemmal Na+/Ca2+ exchanger (NCX), sarcoplasmic reticulum Ca2+ ATPase (SERCA2a), ryanodine receptor (RyR2), and phospholamban (PLB) mRNA in rat myocardium. Male 30-day-old Wistar rats were fed a standard (control) or high-fat diet (obese) for 15 weeks. Obesity was defined as increased percent of body fat in carcass. The mRNA expression of Ca2+-related genes in the left ventricle was measured by RT-PCR. Compared with control rats, the obese rats had increased percent of body fat, area under the curve for glucose, and leptin and insulin plasma concentrations. Obesity also caused an increase in the levels of SERCA2a, RyR2 and PLB mRNA (P < 0.05) but did not modify the mRNA levels of Cacna1c and NCX. These findings show that obesity induced by high-fat diet causes cardiac upregulation of Ca2+ transport_related genes in the sarcoplasmic reticulum.
Assuntos
Canais de Cálcio/genética , Proteínas de Ligação ao Cálcio/genética , ATPases Transportadoras de Cálcio/genética , Miocárdio/metabolismo , Obesidade/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Trocador de Sódio e Cálcio/genética , Animais , Canais de Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Homeostase , Masculino , Miocárdio/química , Obesidade/genética , RNA Mensageiro , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sarcolema/química , Sarcolema/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Regulação para CimaRESUMO
Obesity is a complex multifactorial disorder that is often associated with cardiovascular diseases. Research on experimental models has suggested that cardiac dysfunction in obesity might be related to alterations in myocardial intracellular calcium (Ca2+) handling. However, information about the expression of Ca2+-related genes that lead to this abnormality is scarce. We evaluated the effects of obesity induced by a high-fat diet in the expression of Ca2+-related genes, focusing the L-type Ca2+ channel (Cacna1c), sarcolemmal Na+/Ca2+ exchanger (NCX), sarcoplasmic reticulum Ca2+ ATPase (SERCA2a), ryanodine receptor (RyR2), and phospholamban (PLB) mRNA in rat myocardium. Male 30-day-old Wistar rats were fed a standard (control) or high-fat diet (obese) for 15 weeks. Obesity was defined as increased percent of body fat in carcass. The mRNA expression of Ca2+-related genes in the left ventricle was measured by RT-PCR. Compared with control rats, the obese rats had increased percent of body fat, area under the curve for glucose, and leptin and insulin plasma concentrations. Obesity also caused an increase in the levels of SERCA2a, RyR2 and PLB mRNA (P < 0.05) but did not modify the mRNA levels of Cacna1c and NCX. These findings show that obesity induced by high-fat diet causes cardiac upregulation of Ca2+ transport_related genes in the sarcoplasmic reticulum.
Assuntos
Animais , Masculino , Ratos , Canais de Cálcio/genética , Proteínas de Ligação ao Cálcio/genética , ATPases Transportadoras de Cálcio/genética , Miocárdio/metabolismo , Obesidade/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Trocador de Sódio e Cálcio/genética , Canais de Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Homeostase , Miocárdio/química , Obesidade/genética , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Mensageiro , Sarcolema/química , Sarcolema/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Regulação para CimaRESUMO
OBJECTIVES: To examine the effects of triiodothyronine (T3), 17beta-estradiol (E2), and tamoxifen (TAM) on transforming growth factor (TGF)-alpha gene expression in primary breast cancer cell cultures and interactions between the different treatments. METHODS AND RESULTS: Patients included in the study (no.=12) had been newly diagnosed with breast cancer. Fresh human breast carcinoma tissue was cut into 0.3- mm slices. These slices were placed in six 35-mm dishes on 2-ml organ culture medium. Dishes received the following treatments: dish 1: ethanol; dish 2: T3; dish 3: T3+TAM; dish 4: TAM; dish 5: E2; dish 6: E2+TAM. TGF-alpha mRNA content was normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA levels. All tissues included in this study were positive for estrogen receptor (ER) and thyroid hormone receptor expression. Treatment with T3 for 48 h significantly increased TGF-alpha mRNA levels compared to controls (15-fold), and concomitant treatment with TAM reduced expression to 3.4-fold compared to controls. When only TAM was added to the culture medium, TGF-alpha mRNA expression increased 5.3-fold, significantly higher than with all other treatment modalities. CONCLUSION: We demonstrate that TGF-alpha mRNA expression is more efficiently upregulated by T3 than E2. Concomitant treatment with TAM had a mitigating effect on the T3 effect, while E2 induced TGF-alpha upregulation. Our findings show some similarities between primary culture and breast cancer cell lines, but also some important differences: a) induction of TGF-alpha, a mitogenic protein, by TAM; b) a differential effect of TAM that may depend on relative expression of ER alpha and beta; and c) supraphysiological doses of T3 may induce mitogenic signals in breast cancer tissue under conditions of low circulating E2.