Effect of chronic nutritional burden on the renal dysfunction in rats: role of oxidative stress (age / RAGE)

• Grant number: 11/20950-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2012
• End date: February 28, 2014
• Field of knowledge: Health Sciences - Nutrition
• Principal Investigator: Camila Renata Corrêa
• Grantee: Maria Eugenia Lopes Navarro
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Obesity is associated with increased risk of mortality and reduced life expectancy, especially for presenting various comorbidities such as type 2 diabetes mellitus, dyslipidemia, insulin resistance and hypertension. Epidemiological studies show that kidney disease is also a common factor in obesity. Oxidative stress has been implicated as a factor inducing renal disease with increasing weight, because this condition increase glycation end products (AGEs). These products are very reactive and when formed in excess fall in circulation and can reach several organs including the kidney, the main organ of excretion of these products. This exposure, depending on the intensity and duration, can be an important factor in damage to the kidney tissue, because the action of these products occurs via receptors specific for them, the RAGE (receptor for glycation end products). The junction AGE / RAGE promotes inflammation with consequent organ dysfunction. Thus, the study aims to evaluate the influence of chronic nutritional burden on the formation of AGEs and RAGE receptor expression in the kidney, as well as the relationship between these factors function and renal inflammation. For that will be used male Wistar rats (n = 60), 30 days old. The animals will be randomly divided to receive control diet (C) or high calorie (H) for 6, 12 and 24 weeks, totaling six independent experimental groups (C6, C12, C24, H6, H12, H24, n = 15 animals / group ). The C rats receive standard rodent chow (RC 1765 Focus, Agroceres ®, Rio Claro, São Paulo, Brazil) and a group H calorie diet, consisting of: powder feed (CR 1765 Focus, Agroceres ®, Rio Claro, São Paulo, Brazil), processed foods, palm oil, protein supplements, vitamin and mineral mixture, in addition, animals in the group H will also receive the addition of 300 g of sucrose in the drinking water, the offers will be food and water ad libitum . The consumption of diets and caloric intake will be checked every day, the caloric intake is determined by the product of consumption and energy content of diets. Body weight is measured weekly and the rest of the evaluations will be conducted at 6, 12 and 24 weeks. The index of adiposity is used as an indicator of obesity, assessment of comorbidities are hypertension, glucose and lipid profile, evaluation of the function through the kidney urea, creatinine and total protein in the blood and urine of 24 h, the structural evaluation of the kidney and dosage of serum AGEs. In the kidney is determined the gene expression of RAGE. (AU)