There was a main effect of supplemental SMSC on increasing fasting blood glucose (P < .05) ( Table 2). Within the HIF groups, SMSC caused a significant increase in fasting blood glucose (P < .05), and within the LIF groups, a trend was apparent for the effect of SMSC (P = .075). Fasting insulin levels were not different between groups (data not shown). Supplementing mice with 3 mg/kg SMSC did not result in a significant difference in the response

to a glucose challenge as determined by the area under the curve (AUC) for the glucose tolerance test (GTT); however, a trend was apparent (main effect of SMSC, P = .08) ( Fig. 1). This trend for increased IR is consistent with the impaired fasting blood glucose in these animals ( Table 2). The glucose tolerance pattern BKM120 price observed in the absence of increased dietary IF also tended to be higher

with supplemental LDK378 clinical trial SMSC (P = .08), whereas no such effect was apparent in the animals consuming high IF ( Fig. 1). Basal AMPK activation was determined via immunoblot for pAMPK in muscle and liver samples. Surprisingly, the HIF diet had a main effect of decreased AMPK phosphorylation in red quadriceps (RQ) (Fig. 2B) and white quadriceps (WQ) (Fig. 2A) and tibialis anterior (TA) muscles (Fig. 2C). The basal level of pAMPK in the liver remained unchanged in all groups (Fig. 2D). To investigate AMPK activation in muscle more thoroughly, we also measured the protein expression of the upstream kinase LKB1 (Fig. 3) and the downstream target of AMPK, ACC in the same tissues (Fig. 4). A main effect for decreased LKB1 protein in the HIF groups was consistent PtdIns(3,4)P2 with decreased AMPK phosphorylation in the RQ (Fig. 3C) and mixed fiber-type TA muscle (Fig. 3B). Moreover, in both the TA and the RQ muscles, where we observed reduced AMPK phosphorylation and LKB1 content, there were no significant differences or trends for reduced ACC phosphorylation (Fig. 4B and C). As both Cyt C and UCP3 are markers of mitochondrial content and AMPK is known to affect mitochondrial content, we measured protein expression via immunoblot to

further investigate metabolic response to SMSC and IF. No differences were observed in skeletal muscle expression of either Cyt C (Fig. 5A, C, and E) or UCP3 (Fig. 5B, D, and F). We investigated changes in total GLUT4 protein expression in the WQ, TA, and RQ muscles. Despite increased fasting glucose and a trend for reduced glucose tolerance in mice given SMSC, GLUT4 protein levels were unchanged compared with mice that received dietary IF alone (Fig. 6A-C). The primary focus of this study was to examine the impact of SMSC supplementation with or without HIF intake on basal glucose management. Based on previous work and available information from human studies, we hypothesized that (1) SMSC would have a negative impact on basal glucose management and (2) increasing the dietary content of IF would attenuate this effect.