The regulation of adiponectin receptors expression by acute exercise in mice

Adiponectin is an adipocyte-derived factor that plays a pivotal role in lipid and glucose metabolism. Recently, two types of adiponectin receptors (AdipoR1 and AdipoR2) were identified. While, although physical exercise is useful for improving insulin sensitivity, the effect of physical exercise on adiponectin and adiponectin receptors are still unclear. In present study, we investigated whether acute exercise affects the plasma adiponectin concentration and expression of adiponectin receptor in skeletal muscle and liver in healthy mice C57BL/6. Following an acute exercise, plasma glucose, insulin, FFA, and adiponectin were measured. The mRNA levels of AdipR1 and AdipoR2 were also analyzed. Although acute exercise did not significantly change plasma adiponectin concentration at 2 hours or 18 hours after the exercise compared with control group, the expression levels of AdipoR1 significantly increased in both skeletal muscle (2H: 1.2-fold, p=0.0423, 18H: 1.4-fold, p=0.0006) and liver (2H: 1.3-fold, p=0.0448) compared with control group. In contrast, the level of AdipoR2 mRNA was decreased in skeletal muscle (18H: 0.8-fold, p=0.027) and liver (2H: 0.9-fold, p=0.1551) compared with control group. Additionally, the transcription factor Foxo1 mRNA expression level was also significantly increased in skeletal muscle (2H: 10-fold, p = 0.0001, 18H: 3-fold, p = 0.0424) and liver (2H: 2-fold, p=0.002, 18H: 2-fold, p=0.0014) compared with control group by the acute exercise. These findings suggest that acute exercise affects the expression level of adiponectin receptors, and an increase of Foxo1 expression might be relative to regulate adiponectin receptors.