Physical exercise reduces pyruvate carboxylase (PCB) and contributes to hyperglycemia reduction in obese mice
The present study evaluated the effects of exercise training on pyruvate carboxylase protein (PCB) levels in hepatic tissue and glucose homeostasis control in obese mice. Swiss mice were distributed into three groups: control mice (CTL), fed a standard rodent chow; diet-induced obesity (DIO), fed an obesity-inducing diet; and a third group, which also received an obesity-inducing diet, but was subjected to an exercise training protocol (DIO + EXE). Protocol training was carried out for 1 h/d, 5 d/wk, for 8 weeks, performed at an intensity of 60% of exhaustion velocity. An insulin tolerance test (ITT) was performed in the last experimental week. Twenty-four hours after the last physical exercise session, the animals were euthanized and the liver was harvested for molecular analysis. Firstly, DIO mice showed increased epididymal fat and serum glucose and these results were accompanied by increased PCB and decreased p-Akt in hepatic tissue. On the other hand, physical exercise was able to increase the performance of the mice and attenuate PCB levels and hyperglycemia in DIO + EXE mice. The above findings show that physical exercise seems to be able to regulate hyperglycemia in obese mice, suggesting the participation of PCB, which was enhanced in the obese condition and attenuated after a treadmill running protocol. This is the first study to be aimed at the role of exercise training in hepatic PCB levels, which may be a novel mechanism that can collaborate to reduce the development of hyperglycemia and type 2 diabetes in DIO mice.
KeywordsObesity Type 2 diabetes Physical exercise PCB Hyperglycemia
The authors would like to thank FAPESP (2013/21491-2), CNPq, CAPES and FAEPEX, for their indispensable support.
V.R.M. wrote the paper and had the overall responsibilities of the experiments of this study. V.R.M., R.C.G., B.M.C., G.P.F., M.R.S. and R.S.G. designed and performed the experiments, data collection and statistical analysis; R.S.G., J.D.B. and L.P.M. contributed to data analysis; A.R.S.S., D.E.C., E.R.R. and J.R.P contributed to discussion and supported the financial costs. All the authors have read and approved this manuscript.
Compliance with ethical standards
This study was funded by FAPESP (2013/21491-2 and 2016/18488-8).
Conflict of interest
The authors declare that they have no conflict of interest.
The experimental procedures were approved by the Ethics Committee on Animal Use, Campinas University State–UNICAMP (no. 2805-1). All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. This article does not contain any studies with human participants performed by any of the authors.
- 7.Samuel VT, Beddow SA, Iwasaki T et al (2009) Fasting hyperglycemia is not associated with increased expression of PEPCK or G6Pc in patients with type 2 diabetes. Diabetes 106:12121–12126Google Scholar