scholarly journals Suspected vagal reflex and hyperkalaemia inducing asystole in an anaesthetised horse

2021 ◽  
Author(s):  
Aoife Ryan ◽  
Matthew Gurney ◽  
Roswitha Steinbacher
Keyword(s):  
Vagal Reflex

scholarly journals NMDA Receptor-Dependent Synaptic Activity in Dorsal Motor Nucleus of Vagus Mediates the Enhancement of Gastric Motility by Stimulating ST36

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Xinyan Gao ◽  
Yongfa Qiao ◽  
Baohui Jia ◽  
Xianghong Jing ◽  
Bin Cheng ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Gastric Motility ◽  
Low Frequency ◽  
Synaptic Activity ◽  
Motor Nucleus ◽  
Dorsal Motor Nucleus ◽  
Vagal Reflex ◽  
Precise Molecular Mechanism ◽  
Lines Of Evidence

Previous studies have demonstrated the efficacy of electroacupuncture at ST36 for patients with gastrointestinal motility disorders. While several lines of evidence suggest that the effect may involve vagal reflex, the precise molecular mechanism underlying this process still remains unclear. Here we report that the intragastric pressure increase induced by low frequency electric stimulation at ST36 was blocked by AP-5, an antagonist of N-methyl-D-aspartate receptors (NMDARs). Indeed, stimulating ST36 enhanced NMDAR-mediated, but not 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic-acid-(AMPA-) receptor-(AMPAR-) mediated synaptic transmission in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV). We also identified that suppression of presynapticμ-opioid receptors may contribute to upregulation of NMDAR-mediated synaptic transmission induced by electroacupuncture at ST36. Furthermore, we determined that the glutamate-receptor-2a-(NR2A-) containing NMDARs are essential for NMDAR-mediated enhancement of gastric motility caused by stimulating ST36. Taken together, our results reveal an important role of NMDA receptors in mediating enhancement of gastric motility induced by stimulating ST36.

Electrophysiological-anatomic correlates of ATP-triggered vagal reflex in the dog. III. Role of cardiac afferents

1996 ◽  
Vol 270 (5) ◽  
pp. H1785-H1790 ◽  
Author(s):  
G. Katchanov ◽  
J. Xu ◽  
C. M. Hurt ◽  
A. Pelleg
Keyword(s):  
Carotid Artery ◽  
Common Carotid Artery ◽  
Left Common Carotid Artery ◽  
Descending Aorta ◽  
Chronotropic Action ◽  
Vagal Reflex ◽  
Vagal Afferent ◽  
The Asymmetry ◽  
Cardiac Afferents ◽  
Afferent Terminals

To test the hypothesis that the asymmetry in the afferent traffic of the intra-right atrium (RA) ATP-triggered vagal reflex is due to the stimulation by ATP of extrapulmonary (i.e., cardiac) vagal chemosensitive afferent terminals, ATP, adenosine, and capsaicin were given into the canine RA and the aortic root (AR; n = 12); ATP and adenosine were also administered into the left common carotid artery and the descending aorta (n = 6). The negative chronotropic action [i.e., suppression of sinus node (SN) automaticity] of the test compounds and time to peak effect (tp) were determined. Under baseline conditions, ATP given into the left common carotid artery had a relatively very small effect. ATP given into the descending aorta had no effect. In contrast, intra-RA and intra-AR ATP markedly suppressed SN automaticity, the former less than the latter; the opposite was true for capsaicin. Intra-RA adenosine was much less potent than intra-RA ATP. The tp of intra-RA ATP and intra-RA adenosine were larger than the tp of intra-AR ATP. Pulmonary denervation did not alter the effects of intra-RAATP, intra-ARATP, or intra-AR capsaicin but almost abolished the effect of intra-RA capsaicin. Subsequent bilateral, but not left, cervical vagotomy markedly reduce the effects of ATP and eliminated the difference between the effects of ATP and adenosine. In addition, tp of intra-RA ATP and intra-AR ATP increased substantially and were similar to tp of adenosine. It was concluded that 1) ATP can stimulate vagal afferent terminals not only in the lungs but also in the heart, 2) the latter constitutes the vagal component of the negative chronotropic action of intra-RA or intra-AR ATP on SN automatically, and 3) the asymmetry in the vagal afferent traffic elicited by ATP in the heart (i.e., right vagal dominance) supersedes the symmetrical vagal afferent traffic triggered by intrapulmonary ATP.

Posterior cricoarytenoid and diaphragm activities during tidal breathing in neonates

1988 ◽  
Vol 64 (5) ◽  
pp. 1968-1978 ◽  
Author(s):  
P. C. Kosch ◽  
A. A. Hutchinson ◽  
J. A. Wozniak ◽  
W. A. Carlo ◽  
A. R. Stark
Keyword(s):  
Newborn Infants ◽  
Emg Activity ◽  
Time Interval ◽  
Sudden Increase ◽  
Tidal Breathing ◽  
Term Neonates ◽  
Dynamic Maintenance ◽  
Sequential Activation ◽  
Vagal Reflex ◽  
Posterior Cricoarytenoid

To investigate airflow regulation in newborn infants, we recorded airflow, volume, diaphragm (Di), and laryngeal electromyogram (EMG) during spontaneous breathing in eight supine unsedated sleeping full-term neonates. Using an esophageal catheter electrode, we recorded phasic respiratory activity consistent with that of the principal laryngeal abductors, the posterior cricoarytenoids (PCA). Sequential activation of PCA and Di preceded inspiration. PCA activity typically peaked early in inspiration followed by either a decrescendo or tonic EMG activity of variable amplitude during expiration. Expiratory airflow retardation, or braking, accompanied by expiratory prolongation and reduced ventilation, was commonly observed. In some subjects we observed a time interval between PCA onset and a sudden increase in expiratory airflow just before inspiration, suggesting that release of the brake involved an abrupt loss of antagonistic adductor activity. Our findings suggest that airflow in newborn infants is controlled throughout the breathing cycle by the coordinated action of the Di and the reciprocal action of PCA and laryngeal adductor activities. We conclude that braking mechanisms in infants interact with vagal reflex mechanisms that modulate respiratory cycle timing to influence both the dynamic maintenance of end-expiratory lung volume and ventilation.

scholarly journals Transient Asystole during Surgery for Intracranial Unruptured Aneurysms caused by Excitation of the Trigemino-vagal Reflex : Two Case Reports

2014 ◽  
Vol 23 (8) ◽  
pp. 673-677
Author(s):  
Teishiki Shibata ◽  
Nobuyuki Sakai ◽  
Shoichi Tani ◽  
Hidemitsu Adachi ◽  
Chiaki Sakai ◽  
...  
Keyword(s):  
Case Reports ◽  
Unruptured Aneurysms ◽  
Vagal Reflex

scholarly journals Cardioneuroablation: Catheter Vagal Denervation as a New Therapy for Cardioinhibitory Syncope

2020 ◽  
Vol 32 (3) ◽  
pp. 182-196
Author(s):  
José Carlos Pachon Mateos ◽  
Enrique I Pachón Mateos ◽  
Christian Higuti ◽  
Tomas Guilhermo Santillana Peña ◽  
Tasso Julio Lobo ◽  
...  
Keyword(s):  
Heart Disease ◽  
Preventive Measures ◽  
Therapeutic Option ◽  
Vasovagal Syncope ◽  
Pacemaker Implantation ◽  
Young Patients ◽  
Loss Of Consciousness ◽  
Spectral Mapping ◽  
Transient Loss ◽  
Vagal Reflex

The vasovagal syncope is the most frequent cause of transient loss of consciousness, especially in young people without significant heart disease. The malignant cardioinhibitory form is caused by abrupt and intense vagal reflex with or without defined triggers. Refractory cases to preventive measures and pharmacological handling has been treated with definitive pacemaker implantation. Besides showing questionable results, pacemaker implantation is highly rejected by young patients. In the late 1990s, we proposed specific vagal denervation by catheter ablation and spectral mapping, for paroxysmal AF, functional bradyarrhythmias and severe cases of malignant cardioinhibitory syncope giving rise to cardioneuroablation. Recently, many authors worldwide have been reproducing the cardioneuroablation results where elimination or significant reduction of the vagal response were observed, which abolished symptoms in more than 75% of patients followed up to 14 years, without complications. Therefore, cardioneuroablation has shown to be a real therapeutic option in malignant syncope cardioinhibitory and in any exclusive vagal mediated bradyarrhythmia without the need for pacemaker implantation.

A Possible Reflex Mechanism of Hypotensive Action of Extract from Cassia Tora Seeds

1976 ◽  
Vol 04 (03) ◽  
pp. 249-255 ◽  
Author(s):  
Anthony Koo ◽  
W. S. Chan ◽  
K. M. Li
Keyword(s):  
Hypotensive Effect ◽  
Reduce Blood Pressure ◽  
Vasomotor Tone ◽  
Chinese Medicinal Herb ◽  
Hypotensive Action ◽  
Cassia Tora ◽  
Reflex Mechanism ◽  
Sympathetic Nervous Systems ◽  
Vagal Reflex ◽  
Sympathetic Nervous

The Chinese medicinal herb Chueh-ming-tzu, seeds of Cassia tora(Leguminosae) Linn, elicits hypotensive effects in anesthetized rats. Experimental results indicate that the hypotensive effect of the Cassia tora extract possibly involves a vagal reflex which reciprocally alters the vasomotor tone of the centrally emanating sympathetic nervous system. It is shown that the capacity of the Cassia tora extract to reduce blood pressure is significantly reduced in vagotomized rats and that hypotensive effects are greatly antagonized in rats whose sympathetic nervous systems are interrupted by transection of the spinal cord.

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