Study on the difference of orthodontic tooth movement rate and pressure side bone remodeling between obese and obesity-resistant rats / 上海交通大学学报（医学版）

Objective: To investigate on the difference of the orthodontic tooth movement rate and pressure side bone remodeling between diet-induced obese rats and diet-resistant rats. Methods: Forty male Sprague-Dawley rats were randomly divided into two groups, including the normal diet (ND) group and high-fat diet (HFD) group. And then the HFD group was subdivided into diet-induced obese (DIO) group (n=10) and diet-resistant (DR) group (n=10). Orthodontic applications were placed between the left upper first molar and incisors in rats respectively. After orthodontic treatment for 14 d, the rats were executed and their maxillae were harvested bilaterally. The number of osteoclasts in 3 groups were observed by tartrate-resistant acid phosphatase (TRAP) staining. The expression of osteocalcin in 3 groups was observed by immunohistochemical staining. The tooth movement distance and trabecular bone parameters on the pressure side were measured by Micro-CT. Results: The rate of orthodontic tooth movement was significantly lower in the DR group than that in the DIO and ND groups (P=0.000, P=0.005). After orthodontic treatment for 14 d, the bone mineral density, percentage trabecular bone volume/total volume, trabecular number and trabecular thickness in the DR group were significantly higher than those in the DIO group (P=0.001, P=0.000, P=0.005, P=0.000). The number of osteoclasts in the DR group was significantly lower than that in the ND group and DIO group (P=0.005, P=0.001). The expression of osteocalcin was higher in the DIO group than that in the ND group (P=0.047). Conclusion: High-fat diet-induced obesity or obesity-resistance may affect bone remodeling process during orthodontic treatment by promoting or inhibiting osteoclastogenesis, thereby affecting the rate of tooth movement.

Obesity Resistance Promotes Mild Contractile Dysfunction Associated with Intracellular Ca2+ Handling / Resistência à Obesidade Promove Disfunção Contrátil Leve Associada com Trânsito Ca2+ Intracelular

Abstract Background: Diet-induced obesity is frequently used to demonstrate cardiac dysfunction. However, some rats, like humans, are susceptible to developing an obesity phenotype, whereas others are resistant to that. Objective: To evaluate the association between obesity resistance and cardiac function, and the impact of obesity resistance on calcium handling. Methods: Thirty-day-old male Wistar rats were distributed into two groups, each with 54 animals: control (C; standard diet) and obese (four palatable high-fat diets) for 15 weeks. After the experimental protocol, rats consuming the high-fat diets were classified according to the adiposity index and subdivided into obesity-prone (OP) and obesity-resistant (OR). Nutritional profile, comorbidities, and cardiac remodeling were evaluated. Cardiac function was assessed by papillary muscle evaluation at baseline and after inotropic maneuvers. Results: The high-fat diets promoted increase in body fat and adiposity index in OP rats compared with C and OR rats. Glucose, lipid, and blood pressure profiles remained unchanged in OR rats. In addition, the total heart weight and the weight of the left and right ventricles in OR rats were lower than those in OP rats, but similar to those in C rats. Baseline cardiac muscle data were similar in all rats, but myocardial responsiveness to a post-rest contraction stimulus was compromised in OP and OR rats compared with C rats. Conclusion: Obesity resistance promoted specific changes in the contraction phase without changes in the relaxation phase. This mild abnormality may be related to intracellular Ca2+ handling.

Resumo Fundamento: A obesidade induzida por dieta é frequentemente utilizada para demonstração de disfunção cardíaca. No entanto, alguns ratos, como humanos, são suscetíveis ao desenvolvimento de um fenótipo de obesidade, enquanto outros são resistentes. Objetivo: Avaliar a relação entre resistência à obesidade e função cardíaca e o impacto da resistência à obesidade no trânsito de cálcio. Métodos: Ratos Wistar machos com trinta dias de idade foram distribuídos em dois grupos com 54 animais cada: controle (C; dieta padrão) e obesos (quatro dietas palatáveis hiperlipídicas) por 15 semanas. Após o protocolo experimental, os ratos alimentados por dietas hiperlipídicas foram classificados de acordo com o índice de adiposidade e subdivididos em propensos à obesidade (PO) e resistentes à obesidade (RO). Foram avaliados o perfil nutricional, comorbidades e remodelação cardíaca. A função cardíaca foi avaliada pelo estudo do músculo papilar isolado em condições basais e após manobras inotrópicas. Resultados: As dietas hiperlipídicas promoveram aumento na gordura corporal e no índice de adiposidade em ratos PO comparados com ratos C e RO. Os perfis de glicose, lipídios e pressão arterial permaneceram inalterados em ratos RO. Além disso, os ratos RO apresentaram peso total do coração e dos ventrículos direito e esquerdo mais baixos do que ratos PO, mas semelhantes aos ratos C. Os músculos cardíacos de todos os ratos apresentaram dados semelhantes na condição basal, mas a resposta miocárdica a um estímulo de contração pós-pausa estava comprometida em ratos PO e RO em comparação aos ratos C. Conclusão: A resistência à obesidade promoveu alterações específicas na fase de contração, sem alterar a fase de relaxamento. Esta anormalidade leve pode estar relacionada com o trânsito intracelular de Ca+2.

Effects of Difference Chinese Medicinal Herbs for Tonifying Spleen on Obesity Degree and Insulin Resistance in Diet-induced Obesity Rats / 中国中医药信息杂志

Objective To observe the effects of Chinese medicinal herbs with the efficacy of invigorating spleen, upbearing the clear, and tonifying spleen on the obesity degree, fat hormones, and insulin resistance in diet-induced obesity (DIO) rats;To choose better anti-obesity herbs from different Chinese medicinal herbs that can tonify spleen. Methods Among the 130 Wistar rats, 10 were chosen as the blank control group (fed with basal forage), and the remaining 120 were administered with high-fat high-nutrition forage for 13 weeks. According to weight, 50 DIO rats and 10 diet-induced obesity resistance (DIO-R) rats were obtained. DIO rats were divided into model group (normal saline), sibutramine group, invigorating spleen group (Atractylodix Rhizome and Magnoliae Officinalis Cortex), upbearing the clear group (Bupleuri Radix and Aurantii Fructus Immaturus) and medicine for tonifying qi and spleen group (Astragali Radix). All groups received gavage with corresponding drugs. Rats in the blank control group and the DIO-R group received gavage with normal saline. The basal forage was administered to rats in the blank control group, while high-fat forage was continually given to rats in the other six groups. Insulin resistance index (IRI), blood glucose, triglycerides, cholesterol, tumor necrosis factor α (TNF-α) and adiponectin were detected after blood withdrawing. TNF-α and adiponectin in the fat homogenate were examined. Results Compared with the blank control group, body weight, IRI, and cholesterol of rats in the model group significantly increased (P<0.01);adiponectin in homogenate reduced (P<0.01);serum and adipose homogenate TNF-α increased (P<0.01). Compared with model group, body weight, IRI, cholesterol of rats in DIO-R group significantly decreased (P<0.01);adiponectin in fat homogenate increased (P<0.01). Body weight and cholesterol of rats in the sibutramine group significantly decreased (P<0.01), while serum and adipose homogenates TNF-αdecreased (P<0.05, P<0.01). Body weight, IRI and cholesterol of rats in upbearing the clear group decreased (P<0.05, P<0.01);serum and adipose homogenate TNF-α decreased (P<0.05, P<0.01);adiponectin increased in fat homogenate (P<0.05). IRI, cholesterol and serum TNF-αof rats in the invigorating spleen group decreased (P<0.05, P<0.01);adiponectin in serum and adipose homogenate increased (P<0.05). BMI, blood glucose, IRI and cholesterol of rats in Astragali Radix group decreased (P<0.05, P<0.01);TNF-α decreased and adiponectin increased in serum and adipose homogenate (P<0.05, P<0.01). Conclusion Astragali Radix could reduce obesity induced by high-fat forage, and its effects on improving glucose and lipid metabolism disorder and IR are better than the other TCM groups. Its mechanism is related to decreasing TNF-α and increasing adiponectin level.

RESEARCH ON THE RELATIONSHIP BETWEEN INSULIN RESISTANCE AND SUSCEPTIBILITY OF OBESITY / 营养学报

Objective To study the differences between diet induced obesity (DIO) and diet induced obesity resistance (DIO-R) during insulin resistance (IR) in rats. Method Male SD rats were fed by high-fat diet 1 (45 % fat kJ) after adaptation. At 3rd week, rats were divided into 3 groups according to their body weight: rats belonging to the middle 1/3 of their body weights were the control group, and was fed by control diet (10 % fat kJ). The heaviest 1/3 and the lightest 1/3 belong to DIO and DIO-R group, respectively, and were fed by high-fat diet 2 (60 % fat kJ). Five rats were selected randomly from each group and sacarified at 3rd, 6th, 8th, 10th and 11th week. The energy intake, body fat contents, fasting blood glucose (FBG), serum lipid, serum insulin, insulin sensitive index(ISI)and leptin of rats were monitored dynamically. Results DIO rats were significantly different from DIO-R and control rats in energy intake, body fat content, FBG, lipid, serum insulin and leptin. Conclusion Fed by the same high-fat diet, DIO rats are more sensitive than DIO-R rats to become IR.

THE DIFFERENTIAL SCREENING OF SERUM PROTEINS IN DIET-INDUCED OBESE AND OBESE-RESISTANT RATS / 营养学报

Objective:To explore the difference in susceptibility to high-fat diet induced obesity in rats,as well as the changes of serum proteins. Method:Forty male SD rats were divided into basic group and high-fat diet group randomly. After 5w feeding DIO(diet-induced obesity)and DIO-R(diet-induced obesity resistance) rats were selected according to their body weight gain. The rats were sacrificed and the changes of serum proteins were screened using WCX2 proteomic chips made by American Ciphergen Biosystems. Results: DIO rats were significantly different from DIO-R rats in body weight,body-fat ratio,blood glucose and blood lipids. At the molecular weight range between 2 to 100 ku,the proteins with molecular weight of 7 945 and 9 513 were significantly expressed differently between DIO and DIO-R rats,and the proteins with molecular weight of 4496, 6152, 6267 were significantly expressed differently between DIO-R and control rats (the rats were fed basic diet). Conclusion:Different susceptibility to DIO or DIO-R was found in SD rats when they were fed high-fat diet. The differentially expressed serum proteins between DIO rats and DIO-R were observed,which might provide the basis for further isolation,purification and identification of these proteins.