Irisin is a newly identified hormone induced in muscle and adipose tissues by physical activity. This protein and its encoding gene have been identified in the brain; in addition, the precursor for irisin, FNDC5, can cross the blood-brain barrier. The fact that irisin is secreted during exercise together with the lower resting heart rate in athletes prompted us to investigate the effect of iris...

The bradycardic response to baroreceptor stimulation is impaired in human and experimental hypertension. Because this bradycardia mainly depends on the vagus, this may reflect a reduced cardiac parasympathetic responsiveness, which would parallel the reduced cardiac adrenergic responsiveness observed in hypertension. To test this hypothesis, 12-week-old spontaneously hypertensive rats (n = 12) ...

Cardioneuroablation (CNA) of ganglionated plexi (GP) is increasingly recognized for its potential to improve atrial fibrillation (AF) ablation outcomes. Computed tomography (CT)-identified epicardial adipose tissue (EAT) represents a promising approach localizing GP. However, the clinical efficacy CT-guided CNA and utility in combination with standard AF unclear. To characterize physiologic out...

The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercis...

Impaired baroreflex sensitivity in diabetes is well described and has been attributed to autonomic diabetic neuropathy. In the present study conducted on acute (10-20 days) streptozotocin (STZ)-induced diabetic rats we examined: 1) cardiac baroreflex sensitivity, assessed by the slope of the linear regression between phenylephrine- or sodium nitroprusside-induced changes in arterial pressure an...

Muskrats (Ondontra zibethicus) are common freshwater diving mammals exhibiting a bradycardia with both forced and voluntary diving. This bradycardia is mediated by vagal innervation; however, if hypoxia is present there may be local factors that also decrease heart rate. Some of these local factors may include ATP-sensitive potassium channel activation and extracellular accumulation of potassiu...

It is unknown whether amiodarone exerts a direct central action on the cardiovascular autonomic nervous system. This study was designed to evaluate the effects of acute amiodarone administration on vagal and sympathetic efferent nerve discharges. Experiments were carried out in 25 decerebrate unanesthetized rats. In one group, vagal activity was recorded from preganglionic fibers isolated from ...

We assessed the relative roles of aortic (ABR), carotid sinus (CBR), and vagal cardiopulmonary baroreceptors in the reflex control of heart rate and vascular resistance during changes in arterial blood pressure. Injections of phenylephrine (PE) and nitroglycerin (NG) were given intravenously to anesthetized rabbits (chloralose-urethane). Reflex, heart rate responses were impaired significantly ...