Dietary supplementation with both fat and MSG can influence the expression of AA-sensing genes
To document the effects of dietary fat and MSG on AA-related gene expression, the expression of a broad spectrum of AA-sensing genes in the kidney, liver and muscle were determined. The results are shown in Fig. 2. Dietary fat can significantly up-regulated the expression of taste receptor type 1 member 1 (T1R1) in the kidney (p = 0.0036), and down-regulated its expression in muscle (p = 0.0434), and G-protein-coupled receptor family C member 6A (GPRC6A) in the liver (p = 0.0342). MSG significantly up-regulated the expression of T1R1 in the kidney (p = 0.0007), and down-regulated the expression of T1R1 in the liver (p = 0.0447). MSG also down-regulated the expression of extracellular Ca2+-sensing receptor (CaR) in the muscle (p = 0.0213), and significantly down-regulated the expression of GPRC6A in the liver (p = 0.002) and muscle (p = 0.0191).