Nicotinamide-rich diet improves physical endurance by up-regulating SUR2A in the heart.
Bottom Line: We have found that mice on nicotinamide-rich diet significantly improved physical endurance, which was associated with significant increase in expression of SUR2A.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 β-adrenergic stimulation.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.
Affiliation: Division of Medical Sciences, Centre for Cardiovascular and Lung Biology, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK.Show MeSH
Mentions: To determine whether a sole increase in SUR2A would have similar effect on physical endurance as a nicotinamide-rich diet, we have taken advantage of transgenic phenotype overexpressing SUR2A alone . Under the exercise-stress test, mice in which the SUR2A was under control of cytomegalovirus promoter performed at a significantly increased level than the littemate controls (Fig. 4). The tolerated workload was ∼2-fold higher in transgenic mice compared with the wild-type animals (tolerated workload was 45.6 ± 2.2 J in wild-type mice and 91.6 ± 13.4 J in SUR2A mice, n = 5–7, P = 0.01; Fig. 4). Time spent on treadmill was significantly increased in SUR2A mice when compared to the wild-type (Fig. 4).
Affiliation: Division of Medical Sciences, Centre for Cardiovascular and Lung Biology, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK.