The role of AMP-activated protein kinase in myocardial tolerance to ischemia and reperfusion injury in type 2 diabetes mellitus and its relation to metformin therapy

Background. Several previous studies suggest that the drug in the biguanide class — metformin, in addition to the well-known hypoglycemic action can exert a significant cardioprotective effect. Molecular mechanisms of cardioprotection mediated by metformin are practically unknown. Objective. To examine the role of AMP-activated protein kinase (AMPK) — a key regulator of energy metabolism in myocardial tolerance to ischemia and reperfusion injury under the action of metformin in animals with type 2 diabetes mellitus (T2DM). Design and methods. The Wistar rats with streptozotocin-induced neonatal type 2 diabetes mellitus were used in the study. Ischemia-reperfusion of the myocardium was modeled according to Langendorf on the isolated heart with the preliminary intraperitoneal administration of metformin for 3 days. Cardioprotective effect of metformin was assessed by hemodynamic parameters and the size of myocardial infarction. AMPK activity in the myocardium was assessed by Western blot analysis. Results. Metformin did not significantly affected infarct size and nature of the postischemic recovery of left ventricular function in control group and in animals with T2DM. At the same time, the infarct size in T2DM was significantly lower than in the controls, which confirms the phenomenon of metabolic preconditioning. Activation of AMPK in the myocardium compared with the control group was observed in animals with T2DM, and in both metformin groups. Administration of metformin to animals with T2DM was accompanied by the maximum increase in AMPK activity. Conclusions. T2DM led to the activation of AMPK and was accompanied by improved myocardial tolerance to ischemia. In the absence of significant cardioprotective effect pre-ischemic systemic administration of metformin led to the increase of AMPK activity in the myocardium that was the highest in the animals with T2DM and metformin administration.

diabetes mellitus, myocardium, AMP-activated proteinkinase, metformin

1. Hurst R.T., Lee R.W. Increased incidence of coronary atherosclerosis in type 2 diabetes mellitus: mechanisms and management // Ann. Intern. Med. — 2003. — Vol. 139, № 10. — P. 824-834.

2. Grundy S.M., Benjamin I.J., Burke G.L. et al. Diabetes and cardiovascular disease: a statement for healthcare professionals from the American Heart Association // Circulation. — 1999. — Vol. 100, № 10. — P. 1134-1146.

3. Kravchuk E., Grineva E., Bairamov A., Galagudza M., Vlasov T. The effect of metformin on the myocardial tolerance to ischemia-reperfusion injury in the rat model of diabetes mellitus type II // Exp. Diabetes Res. — 2011. — Vol. 2011. — P. 907496. Epub 2011 Jun 22. — [Электронный ресурс]. — URL: http://www. ncbi.nlm.nih.gov/pmc/articles/PMC3132893/?tool=pubmed

4. Galagudza M.M., Nekrasova M.K., Syrenskii A.V., Ni-fontov E.M. Resistance of the myocardium to ischemia and the efficacy of ischemic preconditioning in experimental diabetes mellitus // Neurosci. Behav. Physiol. — 2007. — Vol. 37, № 5. — P. 489-493.

5. Muller S., Denet S., Candiloros H. et al. Action of metformin on erythrocyte membrane fluidity in vitro and in vivo // Eur. J. Pharmacol. — 1997. — Vol. 337, № 1. — P. 103-110.

6. Nagi D.K., Yudkin J.S. Effects of metformin on insulin resistance, risk factors for cardiovascular disease, and plasminogen activator inhibitor in NIDDM subjects. A study of two ethnic groups // Diabetes Care. — 1993. — Vol. 16, № 4. — P. 621-629.

7. Wulffele M.G., Kooy A., de Zeeuw D. et al. The effect of metformin on blood pressure, plasma cholesterol and triglycerides in type 2 diabetes mellitus: a systematic review // J. Intern. Med. — 2004. — Vol. 256, № 1. — P. 1-14.

8. Bhamra G.S., Hausenloy D.J., Davidson S.M. et al. Metformin protects the ischemic heart by the Akt-mediated inhibition of mitochondrial permeability transition pore opening // Basic Res. Cardiol. — 2008. — Vol. 103, № 3. — P. 274-284.

9. Calvert J.W., Gundewar S., Jha S. et al. Acute metformin therapy confers cardioprotection against myocardial infarction via AMPK-eNOS-mediated signaling // Diabetes. — 2008. — Vol. 57, № 3. — P. 696-705.

10. UK Prospective Diabetes Study (UKPDS) Group. Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34) // Lancet. — 1998. — Vol. 352, № 9131. — P. 854-865.

11. Hardie D.G., Carling D., Carlson M. The AMP-activated/ SNF1 protein kinase subfamily: metabolic sensors of the eukaryotic cell? // Annu. Rev. Biochem. — 1998. — Vol. 67. — P. 821-855.

12. Hawley S.A., Gadalla A.E., Olsen G.S., Hardie D.G. The antidiabetic drug metformin activates the AMP-activated protein kinase cascade via an adenine nucleotide-independent mechanism // Diabetes. — 2002. — Vol. 51, № 8. — P. 2420-2425.

13. Garvey W.T., Hardin D., Juhaszova M., Dominguez J.H. Effects of diabetes on myocardial glucose transport system in rats: implications for diabetic cardiomyopathy // Am. J. Physiol. — 1993. — Vol. 264, № 3. — P. 837-844.

14. Bagrov Y.Y., Manusova N.B., Egorova I.A. et al. Ma-rinobufagenin, an Endogenous Inhibitor of a-1 Na/K-ATPase, Is a Novel Factor in Pathogenesis of Diabetes Mellitus // Dokl. Biol. Sci. — 2005. — Vol. 404. — P. 333-337.

15. Минасян С.М., Галагудза М.М., Сонин Д.Л. и р. Методика перфузии изолированого сердца крысы // Рег. кров. и микроцирк. — 2010. — Т. 8, № 4. — С. 54-59.

16. Королев Д.В., Александров И.В., Галагудза М.М., Сыренский А.В., Сонин Д.Л., Егорова Е.И. Автоматизация получения и обработки данных физиологического эксперимента // Регионарное кровообращение и микроциркуляция. — 2008. — Т. 7, № 2 (26). — С. 79-84.

17. Ishihara T., Haraguchi G., Konishi M. et al. Effect of adiponectin on cardiac allograft vasculopathy // Circ. J. — 2011. — Vol. 75, № 8. — P. 2005-2012.

18. Kemp B. E., Stapleton D., Campbell D. J. et al. AMP-activated protein kinase, super metabolic regulator // Biochem. Soc. Trans. — 2003. — Vol. 31, № 1. — P. 162-168.

19. Hardie D.G., Scott J.W., Pan D.A., Hudson E.R. Management of cellular energy by the AMP-activated protein kinase system // FEBS Lett. — 2003. — Vol. 546, № 1. — P. 113-120.

20. Shaw R.J., Kosmatka M., Bardeesy N. et al. The tumor suppressor LKB1 kinase directly activates AMP-activated kinase and regulates apoptosis in response to energy stress // Proc. Natl. Acad. Sci. U S A. — 2004. — Vol. 101, № 10. — P. 3329-3335.

21. Winder W.W., Hardie D.G. AMP-activated protein kinase, a metabolic master switch: possible roles in type 2 diabetes // Am. J. Physiol. — 1999. — Vol. 277, № 1, Pt. 1. — P. 1-10.

22. Zhang L., He H., Balschi J.A. Metformin and phenformin activate AMP activated protein kinase in the heart by increasing cytosolic AMP concentration // Am. J. Physiol. Heart. Circ. Physiol. — 2007. — Vol. 293, № 1. — P. 457-466.

23. Rodrigues B., Cam M.C., McNeill J.H. Metabolic disturbances in diabetic cardiomyopathy // Mol. Cell. Biochem. — 1998. — Vol. 180, № 1-2. — P. 53-57.

24. Seymour A.M., Chatham J.C. The effects of hypertrophy and diabetes on cardiac pyruvate dehydrogenase activity // J. Mol. Cell. Cardiol. — 1997. — Vol. 29, № 10. — P. 2771-2778.

25. Schummer C.M., Werner U., Tennagels N. Dysregulated pyruvate dehydrogenase complex in Zucker diabetic fatty rats // Am. J. Physiol. Endocrinol. Metab. — 2008. — Vol. 294, № 1. — P. 88-96.

26. Nishino Y., Miura T., Miki T. et al. Ischemic preconditioning activates AMPK in a PKC-dependent manner and induces GLUT4 up-regulation in the late phase of cardioprotection // Car-diovasc. Res. — 2004. — Vol. 61, № 3. — P. 610-619.

27. Sukhodub A., Jovanovic S., Du Q. et al. AMP-activated protein kinase mediates preconditioning in cardiomyocytes by regulating activity and trafficking of sarcolemmal ATP-sensitive K-channels // J. Cell. Physiol. — 2007. — Vol. 210, № 1. — P. 224-236.

28. Wilcock C., Bailey C.J. Accumulation of metformin by tissues of the normal and diabetic mouse // Xenobiotica. — 1994. — Vol. 24, № 1. — P. 49-57.