INVESTIGADORES
ZENI Susana Noemi
congresos y reuniones científicas
Título:
MODULATING EFFECTS OF IGF I AND LEPTIN LEVELS ON BONE MINERAL CONTENT
Autor/es:
SUAREZ C; FERREIRA MONTEIRO A; RODRIGUEZ P; ZENI SN; FRIEDMAN S
Lugar:
San Francisco, USA
Reunión:
Congreso; Experimental Biology 2006; 2006
Resumen:
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. The experimental rat model consisted of individuals under 50% of energy restriction diets with or without calcium restriction. Forty two weanling Wistar rats were randomly assigned one of the three diets providing a carbohydrate to fat calorie ratio of 1:1 (reference group) (a) or 3:1 calorie ratio with either 0.6% or 0.3% of calcium content (b and c, respectivately). At day= 35, animals were sacrificed. Body weights (BW=g) and lengths (BL=cm) were measured and body composition (percentage of body fat by chemical method AOAC) and bone mineral content (BMC) (by DEXA Lunar DPX) were determined. In five of them serum IGF I and leptin levels were measured (ELISA ng/ml). Results are presented as mean + SD and p<0.05 was considered statistically significant.
Diet
Body length
% body fat
IGF I
Leptin
BMC/BW %
1:1 0,6 % Ca
15.9 ± 0.7
10.0 ± 1.7
706.08 ± 243.09
1.30 ± 0.86
0.34 ± 0.05
3:1 0,6 % Ca
15.5 ± 0.7
7.9 ± 1.5 **
592.88 ± 132.23
0.70 ± 0.45
0.27 ± 0.03 *
3: 1 0,3 % Ca
15.3 ± 0.6 **
6.1 ± 1.2 **
564.1 ± 297.19
0.87 ± 0.74
0.15 ± 0.01**
ANOVA, Dunnett test *P<0.05; **P<0.01.
Diets in which fat were restricted (b and c), affected the percentage 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 serum leptin levels more diminished in a and b, than a. Therefore serum IGF I and leptin appear to account for an accurate bone tissue development.
Awarded by UBACyT O 004.