; Indianapolis, IN, USA) [11]. Data are expressed as the mean ± SEM. The statistical significance of difference in mean values between TGR
and SD rats was assessed by unpaired Student’s t-test or two-way ANOVA (glucagon and pyruvate challenge tests). Significance level was set at p < 0.05. Twelve weeks old TGR rats (0.0269 ± 0.00067 g/g BW) showed no difference in liver weight corrected by body weight when compared with SD rats. (0.0265 ± 0.00047 g/g BW) as illustrated in Fig. 1. Glucagon stimulation test also not demonstrate statistical difference between fasted ABT-737 in vitro TGR rats and SD rats (Fig. 2). Analysis of basal hepatic glycogen measurement showed no variation between TGR (0.4005 ± 0.1562 mg/g) and SD rats (0.5825 ± 0.1778 mg/g) as demonstrated in Fig. 2. In order to evaluate the gluconeogenesis pathway we performed the pyruvate challenge test (Fig. 1). Pyruvate administration in fasting TGR showed a decrease in the synthesis of glucose in these rats compared Fluorouracil ic50 to the SD with the minimum peak for glycemic values of the curve in TGR rats at 30 min (106.8 in SD vs. 85.73 in TGR; P < 0.01) and 45 min (117.0 in SD vs. 98.00 in TGR; P < 0.01). To understand the molecular mechanisms underlying changes in gluconeogenesis and glycogenolysis
we analyzed the levels of glycongen phosphorylase enzyme, PYGB/L/M by Western blotting method (Fig. 2). The total of PYG enzyme level was not altered (4.148 ± 0.6282 in TGR vs. 5.893 ± 0.4164 in SD rats). In addition, real-time PCR analysis revealed a marked decrease in PEPCK expression in TGR hepatic tissue (1.403 ± 0.1441 in SD vs. 0.4598 ± 0.2391 in TGR), without difference in G6Pase expression in TGR and SD rats (0.7363 ± 0.09964
in SD vs. 1.133 ± 0.2475 in TGR) as showed in Fig. 1. In order to confirm the downregulation in gluconeogenesis we evaluated the mRNA expression of HNF-4α, responsible for the regulation of transcription enzymes on gluconeogenesis pathway (Fig. 1), and we observed an important decrease in TGR rats (0.7214 ± 0.1196 in TGR vs. 1.307 ± 0.2023 in SD). It is well documented that Ang-(1-7) presents several effects opposite to those produced by Ang II [13], [15], [20], [22] and [23], however, this is the first study evaluating the role of Ang-(1-7) on liver gluconeogenesis and glycogenolysis. The main result of the present study was Cyclic nucleotide phosphodiesterase to show that transgenic rats with increased circulating Ang-(1-7) presents a decreased activation of the gluconeogenesis pathway, demonstrated by the pyruvate challenge test accompanied by a significantly reduction in PEPCK and HNF4α. The role of Ang II in glucose metabolism is well established. Coimbra et al. [4] demonstrated that administration of Ang II increases hepatic glucose output, mostly by activation of gluconeogenesis pathway in comparison to the glycogenolysis pathway. The present results point to a counterregulatory action of Angiotensin-(1-7) on gluconeogenesis, which opposes the effect of Ang II.