First Author | Sukhodub A | Year | 2011 |
Journal | J Cell Mol Med | Volume | 15 |
Issue | 8 | Pages | 1703-12 |
PubMed ID | 20731746 | Mgi Jnum | J:318030 |
Mgi Id | MGI:6860550 | Doi | 10.1111/j.1582-4934.2010.01156.x |
Citation | Sukhodub A, et al. (2011) Nicotinamide-rich diet improves physical endurance by up-regulating SUR2A in the heart. J Cell Mol Med 15(8):1703-12 |
abstractText | SUR2A is an ATP-binding protein that serves as a regulatory subunit of cardioprotective ATP-sensitive K(+) (K(ATP) ) channels. Based on signalling pathway regulating SUR2A expression and SUR2A role in regulating numbers of fully assembled K(ATP) channels, we have suggested that nicotinamide-rich diet could improve physical endurance by stimulating SUR2A expression. We have found that mice on nicotinamide-rich diet significantly improved physical endurance, which was associated with significant increase in expression of SUR2A. Transgenic mice with solely overexpressed SUR2A on control diet had increased physical endurance in a similar manner as the wild-type mice on nicotinamide-rich diet. The experiments focused on action membrane potential and intracellular Ca(2+) concentration have demonstrated that increased SUR2A expression was associated with the activation of sarcolemmal K(ATP) channels and steady Ca(2+) levels in cardiomyocytes in response to beta-adrenergic stimulation. In contrast, the same challenge in the wild-type was characterized by a lack of the channel activation and rise in intracellular Ca(2+) . Nicotinamide-rich diet was ineffective to increase physical endurance in mice lacking K(ATP) channels. This study has shown that nicotinamide-rich diet improves physical endurance by increasing expression of SUR2A and that this is a sole mechanism of the nicotinamide-rich diet effect. The obtained results suggest that oral nicotinamide is a regulator of SUR2A expression and has a potential as a drug that can improve physical endurance in conditions where this effect would be desirable. |