Methods were devised for the selective alteration of parasympathetic control over the sinoatrial (SA) or the atrioventricular (AV) node in anesthetized, thoracotomized mongrel dogs. Two epicardial sites were located at which parasympathetic nerve fibers enroute to the SA or the AV node could be stimulated or blocked. Selective nerve stimulation was accomplished with brief pulses (0.05 msec), an...

The role of the autonomic nervous system in secretory immunoglobulin A (sIgA) responses to laboratory challenge was explored in a study in which sIgA and cardiovascular activity were recorded at rest and during mental arithmetic and paced breathing. These tasks were selected to preferentially engage the sympathetic and parasympathetic nervous systems, respectively. Mental arithmetic elicited a ...

Long-term endurance training significantly influences how the autonomic nervous system controls heart function. Endurance training increases parasympathetic activity and decreases sympathetic activity in the human heart at rest. These two training-induced autonomic effects, coupled with a possible reduction in intrinsic heart rate, decrease resting heart rate. Long-term endurance training also ...

We conducted this study in an effort to characterize and understand vagal abnormalities in heart failure patients whose sympathetic activity is known. We measured sympathetic (peroneal nerve muscle sympathetic recordings and antecubital vein plasma norepinephrine levels) and vagal (R-R intervals and their standard deviations) activities in eight heart failure patients and eight age-matched heal...

Cardiac output is regulated by the coordinate interactions of stimulatory sympathetic and inhibitory parasympathetic signals. Intracardiac parasympathetic ganglia are integrative centers of cardiac regulation, and modulation of the parasympathetic drive on the heart is accomplished by altering intrinsic cardiac ganglion neuron excitability. The pituitary adenylate cyclase-activating polypeptide...

RATIONALE Parasympathetic regulation of heart rate is mediated by acetylcholine binding to G protein-coupled muscarinic M2 receptors, which activate heterotrimeric G(i/o) proteins to promote G protein-coupled inwardly rectifying K(+) (GIRK) channel activation. Regulator of G protein signaling (RGS) proteins, which function to inactivate G proteins, are indispensable for normal parasympathetic c...

INTRODUCTION Decreased vascular responses to salivary gland stimulation are observed in Sjögren's syndrome patients. We investigate whether impaired vascular responses to parasympathetic stimulation and muscarinic receptor activation in salivary glands parallels hyposalivation in an experimental model for Sjögren's syndrome. METHODS Blood flow responses in the salivary glands were measured by...

The aim of present study was comparison of cardiac autonomic status during different phases of reproductive life in women - in premenopausal women between proliferative and secretory phase, in postmenopausal women and in postmenopausal women receiving hormone replacement therapy (HRT). The study included 30 premenopausal women (Group 1) who were assessed in both proliferative (Group 1A) and sec...

OBJECTIVE To examine the effect of kangaroo care on heart rate variability in a healthy preterm infant. DESIGN Case study. SETTING Private room on a postpartum unit. PARTICIPANT A mother-preterm infant dyad. INTERVENTION Kangaroo (skin-to-skin) care. MAIN OUTCOME MEASURE Heart rate variability, a noninvasive measurement of the sympathetic and parasympathetic components of the autonomi...

Cardiac parasympathetic activity was assessed in 21 patients during the first 24 hours of acute myocardial infarction by measuring abrupt beat by beat changes in RR interval, which are expressed as "RR counts". Eleven patients had inferior wall infarction and 10 had anterior wall myocardial infarction. The whole recording period was analysed in 11 patients (five inferior and six anterior), and ...