MODULATING EFFECTS OF IGF I AND LEPTIN LEVELS ON BONE MINERAL CONTENT

Knowledge the strong relationship between body lipid size and serum leptin levels due to its appetite regulation and the insulin like growth factor (IGF) I involved as a signal of calories, body lipid composition and proteins viability, it is important to begin to answer questions concerning bone formation throughout leptin and IGF I receptors. The aim of this study was to evaluate the strong association among leptin and IGF I levels during active growth. Forty two weanling Wistar rats were randomly assigned one of three diets providing a carbohydrate to lipid calorie ratio of 1:1 (reference group) (a) or 3:1, with either 0.6% or 0.3% of calcium content (b and c, respectively). At age= 35 d, animals were sacrificed. Body weights (BW=g) and lengths (BL=cm) were measured and body composition (% body fat by chemical method AOAC) and bone mineral content (BMC) (DEXA Lunar DPX) were determined. In five of them serum IGF I and leptin levels were measured (ELISA ng/ml). Results as mean ± SD.Diets in which lipids were restricted (b and c), affected the % of body fat and bone mineral content. Body length remained unchanged in adequate calcium diets while there was a tendency towards serum IGF I and leptin levels more diminished in b and c, than a. Serum IGF I and leptin appear to account for an accurate bone tissue development. Awarded by UBACyT O 004.