Effects of acute mechanical stretch on the expression of mechanosensitive potassium channel TREK-1 in rat left ventricle

Abstract

To explore the role of mechanosensitive potassium channel TREK-1, Western blot analysis was used to investigate the expression changes of TREK-1 in left ventricle in acute mechanically stretched heart. Forty Wistar rats were randomly divided into 8 groups (n=5 in each group), subject to single Langendorff perfusion for 0, 30, 60, 120 min and acute mechanical stretch for 0, 30, 60, 120 min respectively. With Langendorff apparatus, an acute mechanically stretched heart model was established. There was no significant difference in the expression of TREK-1 among single Langendorff perfusion groups (P>0.05). As compared to non-stretched Langendorff-perfused heart, only the expression of TREK-1 in acute mechanically stretched heart (120 min) was greatly increased (P<0.05). This result suggested that some course of mechanical stretch could up-regulate the expression of TREK-1 in left ventricle. TREK-1 might play an important role in mechanoelectric feedback, so it could reduce the occurrence of arrhythmia that was induced by extra mechanical stretch.

Keywords

mechanoelectric feedback / mechanosensitive potassium channel / mechanical stretch

References

[1] KohlP., NesbittA. D., CooperP. J., et al.. Sudden cardiac death by Commotio cordis: role of mechano-electric feedback. Cardiovasc Res, 2001, 50: 280-289

[2] RavensU.. Mechano-electric feedback and arrhythmias. Prog Biophys Mol Biol, 2003, 82: 255-266

[3] IsenbergG., KazanskiV., KondratevD., et al.. Differential effects of stretch and compression on membrane currents and [Na⁺] in ventricular myocytes. Prog Biophys Mol Biol, 2003, 82: 43-56

[4] DongheeK.. Fatty acid-sensitive two-pore domain K+ channels. Trends Pharmacol Sci, 2003, 24: 648-654

[5] YasuchikaT., QunhuaH., Ju-ichiA., et al.. Src and multiple MAP kinase activation in cardiac hypertrophy and congestive heart failure under chronic pressure-overload: Comparison with acute mechanical stretch. J Mol Cell Cardiol, 2001, 33: 637-648

[6] HughesS., MagnayJ., ForemanM., et al.. Expression of the mechanosensitive 2PK⁺ channel TREK-1 in human osteoblasts. J Cell Physiol, 2006, 206: 738-748

[7] ChangJ., WasserJ. S., CornelussenR. N. M., et al.. Activation of heat-shock factor by stretch-activated channels in rat hearts. Circulation, 2001, 104: 209-214

[8] LesageF.. Pharmacology of neuronal background potassium channels. Neuropharmacology, 2003, 44: 1-7

[9] JoyH., WeihongL., DavidA.. Differential expression of the mechanosensitive potassium channel TREK-1 in epicardial and endocardial myocytes in rat ventricle. Exp Physiol, 2003, 89: 237-242

[10] ChengL. X., SuF. C., RipenZ., et al.. Changes of expression of stretch-activated potassium channel TREK-1 mRNA and protein in hypertrophic myocardium. J Huazhong Univ Sci and Technol [Med Sci ], 2006, 26(1): 31-33