Effects of sodium nitroprusside and verapamil on lower esophageal sphincter

1980 ◽  
Vol 238 (1) ◽  
pp. G40-G44
Author(s):  
R. K. Goyal ◽  
S. Rattan

Infusions of verapamil (V) and sodium nitroprusside (NP) caused dose-dependent reductions in the lower esophageal sphincter pressure (LESP) in anesthetized opossums. Verapamil caused a gradual fall during the infusion and a gradual recovery upon cessation of the infusion. On the other hand, NP caused a prompt reduction and a prompt recovery. Both the agents also caused a fall in arterial blood pressure, but the fall in LESP was not related to the fall in the blood pressure. Both the agents antagonized the tonic and the phasic components of the LESP and, in large doses, both drugs almost abolished the LESP. Esophageal contractions were also antagonized by both agents, although verapamil was more effective than nitroprusside in this regard. These studies show that phasic and tonic components of LESP are not related to distinctive verapamil and nitroprusside sensitive calcium activation systems. Moreover, the V- and NP-sensitive calcium activation systems may lie in series rather than parallel.

1995 ◽  
Vol 268 (6) ◽  
pp. G1004-G1011 ◽  
Author(s):  
L. A. Blackshaw ◽  
V. Nisyrios ◽  
J. Dent

In urethananesthetized ferrets, basal lower esophageal sphincter pressure (LESP) was unaffected by the 5-hydroxytryptamine3 (5-HT3) receptor antagonist granisetron (0.5 mg/kg) or by greater splanchnic nerve section (GSX), but increased after bilateral vagotomy. Peripheral vagal nerve stimulation caused LES relaxation, often followed by a brief contraction and a prolonged inhibition of LESP. Close intra-arterial injection of 5-HT (5-100 micrograms) had a biphasic effect on LESP, with a brief drop followed by a prolonged increase. Granisetron (0.5 mg/kg i.v.) abolished the initial relaxation and revealed an earlier peak of excitation. This was not influenced by subsequent vagotomy and GSX. In a series of eight additional experiments (series 2), granisetron was given after vagotomy and GSX. In series 2, 5-HT-induced relaxation was unaffected by vagotomy but was significantly reduced after GSX and was further reduced after granisetron, indicating that 5-HT3 receptor mechanisms may lie on a sympathetic neural pathway. Vagotomy had no effect on the excitatory component. GSX had no effect on the amplitude of excitation, but reduced its latency. Granisetron had no further effect on excitation in series 2. In a separate series of 13 experiments (series 3), the excitatory component of the LES response to 5-HT was abolished by ketanserin (2.5 mg/kg i.v.) , after which only relaxation occurred. Both 5-HT2 and 5-HT3 antagonists in combination abolished all effects of 5-HT on LESP. Atropine (400 micrograms/kg i.v., n = 7) had no effect on 5-HT-induced LES responses.(ABSTRACT TRUNCATED AT 250 WORDS)


1977 ◽  
Vol 232 (1) ◽  
pp. E19 ◽  
Author(s):  
A K Mukhopadhyay ◽  
N Weisbrodt

Intravenous administration of dopamine produced a dose-dependent decrease in lower esophageal sphincter pressure and a dose dependent increase in contractile activity of the body of the esophagus. The threshold dose of dopamine was 0.25 mug/kg, and the effect reached a plateau at about 6 mug/kg. A dose of 6 mug/kg of dopamine produced 83%+/-3 (SE) reduction in the lower esophageal sphincter pressure and 12+/-1 (SE) contractions in the body of the esophagus within 5 min of the bolus injection. Atropine, phentolamine, propranolol, and bilateral cervical vagotomy did not modify the effect of dopamine. Both haloperidol and bulbocapnine potently antagonized the effect of dopamine. The amplitude of esophageal contraction in the lower esophagus in response to pharyngeal stimulation and esiogageal distention was significantly increased after administration of haloperidol. It is concluded that intravenous administration of dopamine has potent effects on the motor function of the lower esophageal sphincter and the body of the esophagus. The effect of dopamine is not mediated via the vagal centers in the brain or cholinergic muscarinic and adrenergic receptors. The response of the smooth muscle segment of opossum esophagus to intravenous dopamine is mediated via specific dopamine receptors. The inhibitory dopamine receptors may play a physiological role in controlling the amplitude of esophageal contractions.


2021 ◽  
Vol 10 (1) ◽  
pp. 8-13
Author(s):  
Shankar Baral ◽  
Bidhan NIdhi Paudel ◽  
Ajit Khanal ◽  
Jiwan Thapa ◽  
Bhuwneshwer Yadhav ◽  
...  

Background: Achalasia Cardia is a rare esophageal motility disorder. Among various treatment options, Pneumatic Dilatation (PD) is the most widely used and cost effective modality till date. This is the first observational study aiming to evaluate the short term response and complications of PD for Achalasia Cardia in Nepal. Methods: This prospective observational study was conducted between 28th Jan 2020 to 27th Jan 2021. It included 39 patients with Achalasia Cardia diagnosed by clinical presentation, esophagoscopy, barium esophagogram and high resolution manometry. Two patients of Type III achalasia were excluded from study. Thirty seven patients underwent pneumatic dilatation with 30 mm Rigiflex balloon (Boston Scientific, USA) for a duration of 1 minute. Response was assessed by Eckardts score at 3 and 6 months. Result: Among 39 cases (mean age= 39.03±15.017 years, 59% men), commonest was Type II Achalasia (71.8%) followed by Type I (23.1%) and Type III (5.1%). Dysphagia was present in all patients (100%), followed by weight loss (84.6%), regurgitation (79.5%) and chest pain (35.9%). Mean basal Eckardts score and Lower Esophageal Sphincter pressure of the study population was 7.81±1.24 and 24.40±6.83 respectively. Response to pneumatic dilatation was 89.2%. Eckardts score changed significantly from7.81±1.24 to 1.03±1.82 at 6 months (p<0.001). None of the patients had major complications. Younger age (23±6.377 years) had poor response to treatment, while predilatation Lower Esophageal Sphincter pressure, gender and type of achalasia did not affect the treatment outcome. Conclusion: PD is safe and effective treatment modality for Achalasia. Younger patients have poor response to treatment with Pneumatic Dilatation.  


1978 ◽  
Vol 75 (2) ◽  
pp. 283-285 ◽  
Author(s):  
H.R. Koelz ◽  
G. Lepsien ◽  
A.P. Hollinger ◽  
H. Säuberli ◽  
F. Largiadér ◽  
...  

1977 ◽  
Vol 233 (3) ◽  
pp. E152
Author(s):  
K Schulze ◽  
W J Dodds ◽  
J Christensen ◽  
J D Wood

The opossum esophagus is commonly used as an animal model of the human esophagus. We used esophageal manometry in normal animals to provide basal data about normal esophageal motor functions in vivo in this species. At rest, separate and distinct high pressure zones can be recorded at the level of the lower esophageal sphincter, diaphragmatic hiatus, aortic arch, and upper esophageal sphincter. Each zone demonstrates a characteristic pattern of pressures in the radii of the coronal section and a characteristic response to swallowing. The hiatal and aortic zones can be mistaken for the esophageal sphincters. Pressures in the sphincters fall with swallowing. Peristalsis is not bolus-dependent and occurs with 98% of swallows. Pressures generated by peristalsis are greater in the middle of the esophagus than at the ends. Values for resting lower esophageal sphincter pressure and the characteristics of peristalsis were reproducible between different studies in the same animals.


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