Steroidogenic acute regulatory protein (StAR) is indispensable for steroid hormone synthesis in the adrenal cortex and the gonadal tissues. This study reveals that StAR is also expressed at high levels in nonsteroidogenic cardiac fibroblasts confined to the left ventricle of mouse heart examined 3 days after permanent ligation of the left anterior descending coronary artery. Unlike StAR, CYP11A1 and 3β-hydroxysteroid dehydrogenase proteins were not observed in the postinfarction heart, suggesting an apparent lack of de novo cardiac steroidogenesis.
View Article and Find Full Text PDFThe purpose of this study was to determine the effect of extremely low frequency and weak magnetic fields (WMF) on cardiac myocyte Ca(2+) transients, and to explore the involvement of potassium channels under the WMF effect. In addition, we aimed to find a physical explanation for the effect of WMF on cardiac myocyte Ca(2+) transients. Indo-1 loaded cells, which were exposed to a WMF at 16 Hz and 40 nT, demonstrated a 75 ± 4% reduction in cytosolic Ca(2+) transients versus control.
View Article and Find Full Text PDFBackground And Aim: Mitochondrial calcium overload triggers apoptosis and also regulates ATP production. ATP and uridine-5'-triphosphate (UTP) depletion from hepatic tissue after ischemia causes cell death. ATP and UTP binds to cell membranes of the hepatocytes through P2Y receptors.
View Article and Find Full Text PDFThe involvement of nitric oxide (NO) in the late phase of ischemic preconditioning is well established. However, the role of NO as a trigger or mediator of "classic preconditioning" remains to be determined. The present study was designed to investigate the effects of NO on calcium homeostasis in cultured newborn rat cardiomyocytes in normoxia and hypoxia.
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