A Low-Protein, High-Carbohydrate Diet Stimulates Thermogenesis in the Brown Adipose Tissue of Rats via ATF-2

Abstract The aim of this study was to evaluate thermogenesis in the interscapular brown adipose tissue (IBAT) of rats submitted to low-protein, high-carbohydrate (LPHC) diet and the involvement of adrenergic stimulation in this process. Male rats (~100 g) were submitted to LPHC (6 %-protein; 74 %-carbohydrate) or control (C; 17 %-protein; 63 %-carbohydrate) isocaloric diets for 15 days. The IBAT temperature was evaluated in the rats before and after the administration of noradrenaline (NA) (20 µg 100 g b w−1 min−1). The expression levels of uncoupling protein 1 (UCP1) and other proteins involved in the regulation of UCP1 expression were determined by Western blot (Student’s t test, P ≤ 0.05). The LPHC diet promoted a 1.1 °C increase in the basal temperature of IBAT when compared with the basal temperature in the IBAT of the C group. NA administration promoted a 0.3 °C increase in basal temperature in the IBAT of the C rats and a 0.5 °C increase in the IBAT of the LPHC group. The level of UCP1 increased 60 % in the IBAT of LPHC-fed rats, and among the proteins involved in its expression, such as β3-AR and α1-AR, there was a 40 % increase in the levels of p38-MAPK and a 30 % decrease in CREB when compared to the C rats. The higher sympathetic flux to IBAT, which is a consequence of the administration of the LPHC diet to rats, activates thermogenesis and increases the expression of UCP1 in the tissue. Our results suggest that th...
Source: Lipids - Category: Lipidology Source Type: research