Previous studies have suggested that maintained vagal stimulation or acetylcholine infusion results in a fade of responses in the sinoatrial node but not in the atrioventricular node, implying different muscarinic receptor subtypes in the two regions. We investigated this hypothesis in 23 isolated rabbit atrial preparations made quiescent by continuous superfusion with verapamil (1 microgram/ml...

Although the atrioventricular node (AVN) plays a vital role in blocking many of the atrial impulses from reaching the ventricles during atrial fibrillation (AF), a rapid irregular ventricular rate nevertheless persists. The goals of the present study were to explore the feasibility of novel epicardial selective vagal nerve stimulation for slowing of the ventricular rate during AF and to charact...

As bstract. The reason for increased maximal acid secretory capacity in some patients with duodenal ulcer is uncertain. We postulated that chronically increased cephalic-vagal stimulation may be a cause of increased maximal acid output. To study this, we prepared six male, mongrel dogs with a vagally innervated gastric fistula, a vagally denervated fundic (Heidenhain) pouch, and a cervical esop...

In anesthetized dogs the vagus nerve was stimulated for 2 min; during the first minute the ventricles were driven at a rate higher than the control sinus rate; after discontinuation of the drive, the duration of asystole was prolonged. When the ventricles were driven at a rate lower than the sinus rate during vagal stimulation the subsequent asystole was shortened. Slowing sinus activity by gra...

We have extended our compartmental model [ Am. J. Physiol. 266 ( Cell Physiol. 35): C832-C852, 1994] of the single rabbit sinoatrial node (SAN) cell so that it can simulate cellular responses to bath applications of ACh and isoprenaline as well as the effects of neuronally released ACh. The model employs three different types of muscarinic receptors to explain the variety of responses observed ...

BACKGROUND The vein of Marshall (VOM) is an attractive target during ablation of atrial fibrillation due to its autonomic innervation, its location anterior to the left pulmonary veins and drainage in the coronary sinus. METHODS AND RESULTS We studied 17 dogs. A coronary sinus venogram showed a VOM in 13, which was successfully cannulated with an angioplasty wire and balloon. In 5 dogs, elect...

The stimulation of the central vagus nerve in guinea pigs was applied to study the role of vagal afferent information in the control of breathing. The survival time after bilateral vagotomy was measured in unanesthetized animals, under Hexobarbital anesthesia, and in anesthetized subjects when the central stump of the vagus nerve was stimulated. There were no differences in survival time betwee...

Li, Ying, Jinxia Zhu, and Chung Owyang. Electrical physiological evidence for highand low-affinity CCK-A receptors. Am. J. Physiol. 277 (Gastrointest. Liver Physiol. 40): G469–G477, 1999.—We have demonstrated that under physiological conditions CCK acts through vagal high-affinity CCK-A receptors to mediate pancreatic secretion. In this study, we evaluated the vagal afferent response to endogen...

To better understand the pathophysiological role of angiotensin II (ANG II) in the dynamic autonomic regulation of heart rate (HR), we examined the effects of intravenous administration of ANG II (10 microg.kg(-1).h(-1)) on the transfer function from vagal or sympathetic nerve stimulation to HR in anesthetized rabbits with sinoaortic denervation and vagotomy. In the vagal stimulation group (n =...

We have demonstrated that under physiological conditions CCK acts through vagal high-affinity CCK-A receptors to mediate pancreatic secretion. In this study, we evaluated the vagal afferent response to endogenous CCK in rats and defined the CCK-receptor affinity states and the vagal-receptive field responsive to CCK stimulation using electrophysiological studies. Experiments were performed on a...