NO donor-activated PKC-delta plays a pivotal role in ischemic myocardial protection through accelerated opening of mitochondrial K-ATP channels.

Nitric oxide (NO) can activate protein kinase C (PKC) and the activation of mitochondrial ATP-sensitive potassium (K-ATP) channels is cardioprotective. However, interactions among NO, PKC, and mitochondrial K-ATP channels remain vague. To clarify the cardioprotective mechanism induced by nicorandil, we compared its ability to activate PKC isoforms with that of the mitochondrial K-ATP channel opener, diazoxide.

Effect of long-term beta-blocker therapy on microvolt-level T-wave alternans in association with the improvement of the cardiac sympathetic nervous system and systolic function in patients with non-ischemic heart disease.

The purpose of this study was to test a hypothesis that T-wave alternans (TWA) is improved in association with an improvement in cardiac sympathetic nervous system and systolic function by oral beta-blocker therapy in patients with non-ischemic heart disease (NIHD). TWA testing, (123)I-metaiodobenzylguanidine (MIBG) imaging and echocardiography were performed at the baseline and 3 months after beta-blocker therapy in 26 patients with NIHD and positive TWA. The alternans voltage (V(alt)), the heart-to mediastinal-ratio on the early (e-H/M) and delayed (d-H/M) images, the washout rate (WR), the left ventricular ejection fraction (LVEF), and the calculated rate of change by beta-blocker therapy in each parameter (ie, deltaV(alt), deltae-H/M, deltad-H/M, deltaWR and deltaLVEF) were measured.

Relation between microvolt-level T-wave alternans and cardiac sympathetic nervous system abnormality using iodine-123 metaiodobenzylguanidine imaging in patients with idiopathic dilated cardiomyopathy.

We examined the relation between microvolt-level T-wave alternans and cardiac sympathetic nervous system abnormality using iodine-123 metaiodobenzylguanidine imaging in patients with idiopathic dilated cardiomyopathy. Our results strongly indicate that cardiac sympathetic denervation and accelerated sympathetic nervous activity play important roles in the presence of microvolt-level T-wave alternans in patients with idiopathic-dilated cardiomyopathy.

Excessive ventilatory response during exercise in patients with non-hypoxic pulmonary hypertension.

The slope of the regression line between carbon dioxide output (VCO2) and minute ventilation (VE) (SLOPE) is useful for evaluating ventilation-perfusion inequality during exercise. A cardiopulmonary exercise test was carried out in 8 pulmonary hypertension (PH) patients without hypoxemia (group PH), 38 male patients with old myocardial infarction (group OMI), and 20 healthy men (group Ctrl). The average SLOPE for each group was 36.

Effect of ischemic preconditioning and mitochondrial KATP channel openers on chronic left ventricular remodeling in the ischemic-reperfused rat heart.

The influence of ischemic preconditioning (IP) and mitochondrial ATP-sensitive potassium (mito-KATP) channel openers on chronic left ventricular (LV) remodeling remains unknown, so the effect of IP and mito-KATP channel openers on the LV pressure-volume curve was assessed in rats subjected to 30 min ischemia followed by a 3-week reperfusion. Infarct size was histologically determined at 3 weeks after reperfusion. The LV pressure-volume curve was significantly shifted left by IP, diazoxide and nicorandil compared with the controls.