Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT02427 (Atropine)
 3,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effect of Y-25130 on 5-hydroxytryptamine3 (5-HT3) receptors was investigated using the von Bezold-Jarisch effect (BJE) in anesthetized rats. Intravenous or intraduodenal administration of Y-25130 antagonized the BJE evoked by 5-HT and its effect was over 100 times more potent than that of metoclopramide. Y-25130 also completely blocked the BJE induced by 2-methyl-5-HT, a selective 5-HT3 receptor agonist. The BJE induced by 5-HT was not antagonized by spiperone, ketanserin, phenoxybenzamine, yohimbine and haloperidol, but antagonized by atropine. Atropine inhibited the bradycardia caused by electrical stimulation of the vagus nerve, but Y-25130 had no inhibitory effect. These results indicate that Y-25130 possesses a potent and selective 5-HT3 receptor antagonistic property.
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PMID:[Inhibition by Y-25130 of the von Bezold-Jarisch effect evoked by 5-HT or 2-methyl-5-HT in anesthetized rats]. 180 16

The Bezold-Jarisch reflex is an inhibitory reflex that originates from the heart, is mediated by the vagus nerve, and is manifested by hypotension and bradycardia. We present 4 pediatric cardiac surgical patients, aged 1 day to 9 months, who exhibited cardiovascular collapse in their early postoperative course. In each patient, cardiovascular deterioration was marked by an insidious decrease in arterial blood pressure without an associated change in heart rate, central venous pressure, or airway pressure. Bradycardia followed the decrease in blood pressure. The Bezold-Jarisch reflex was suspected and atropine was administered, first as a bolus injection at 0.01 mg/kg, and later, as a continuous infusion at 0.01 mg.kg-1.h-1. Atropine prevented recurrent episodes of hypotension and bradycardia. We believe the Bezold-Jarisch reflex is more prevalent than previously suspected in postoperative pediatric cardiac surgical patients.
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PMID:Bezold-Jarisch reflex in postoperative pediatric cardiac surgical patients. 189 43

In urethane anesthetized rats, intravenous administration of a bolus of acetaldehyde (diluted 50 times its volume in Ringer Locke solution) induced after a latency of about 1 second, a triple reflex response characterized by transient bradycardia, hypotension and apnea. Intensity of both bradycardia (r = -0.78) and hypotension (r = -0.74) were dose dependent (p less than 0.001). The triple response was blocked by vagotomy. Atropine and hexamethonium blocked bradycardia and hypotension and pretreatment of rats with reserpine (0.5 mg/100 g b.wt., IP) did not change the magnitude of the reflex response. The bolus effect was discarded by injecting the same volume of Ringer Locke solution in control test experiments. Administration of acetaldehyde directly into the left ventricle induced neither bradycardia nor hypotension, thus discarding a Bezold-Jarish reflex response. Administration of acetaldehyde directly into the right ventricle induced an increase in reflex bradycardia, hypotension and apnea with a shorter latency as compared to the intravenous route. The results suggest that the response induced by acetaldehyde is mediated by a reflex increase in vagal tone and probably is initiated in pulmonary vagal afferent fibers associated with the pulmonary J receptors.
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PMID:Cardiorespiratory inhibitory reflex induced by intravenous administration of acetaldehyde in rats. 377 48

Cardiac slowing occurring during diagnostic coronary arteriography was studied in 78 patients. Comparable degrees of slowing occurred with injections into the right and into the left coronary arteries into the contralateral artery, and with injections into the coronary artery giving rise to the sinus node artery and into the contralateral artery. Rapid intracoronary injections of isosmotic dextrose solution produced significantly less slowing than comparable injections of contrast medium. Slow injections of contrast medium produced cardiac slowing comparable to that caused by rapid injections of contrast medium. However, the cardiac slowing was significantly greater than that produced by rapid injections of dextrose solution. Inhalation of 100% oxygen did not alter the heart rate response to injections of contrast medium. Atropine produced dose-related attenuation of cardiac slowing. Bradycardia persisting after cholinergic blockade was significantly greater after injections into the coronary artery supplying the sinus node than it was after injections into the contralateral artery. Coronary arteriography produced transient, occasionally profound, arterial hypotension in 38 of 41 patients in whom arterial pressures were recorded. Arterial pressure did not change in three patients. This study suggests that the cardiac slowing which occurs during coronary arteriography in man is due primarily to a cholinergic reflex which may be a human counterpart of the Bezold-Jarisch reflex, observed heretofore only in experimental animals. This slowing appears to be mediated primarily by receptors sensitive to contrast medium, rather than by changes of coronary artery pressure, and secondarily, by direct depression of sinus node function by contrast medium.
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PMID:Mechanisms mediating bradycardia during coronary arteriography. 443 42

This study reports the occurrence of bradycardia and hypotension (Bezold-Jarisch reflex) induced by myocardial reperfusion. Among 92 patients undergoing interventional catheterization for intracoronary thrombolysis in an early phase of acute myocardial infarction, left anterior descending, right coronary, and left circumflex (LC) arteries were identified as the "infarct vessel" in 44, 41, and 7 cases, respectively. The Bezold-Jarisch reflex occurred in 15 of 23 patients (65%) after right coronary recanalization and in 1 of 34 patients after left anterior descending recanalization. The reflex also was observed in 4 (22%) of 18 patients with nonoccluded or nonrecanalized right coronary arteries. The average time from onset of symptoms to right recanalization was significantly shorter (p less than 0.01) among patients in whom the reflex did not develop. Atropine, postural changes, or temporary pacing, or all 3, were generally sufficient to control symptoms. The findings of this study are substantially parallel to those reported by others and confirm that reperfusion of the inferoposterior myocardium is capable of stimulating a cardioinhibitory reflex. Follow-up data available in 15 patients with occluded and recanalized right coronary arteries indicate that the occurrence of the Bezold-Jarisch reflex after reperfusion is not a reliable predictor of myocardial salvage.
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PMID:Coronary reperfusion and Bezold-Jarisch reflex (bradycardia and hypotension). 686 65

We evaluated the inhibitory effects of YM060 [(R)-5-[(1-methyl-1H-indol- 3-yl)carbonyl]-4,5,6,7-tetrahydro-1H-benzimidazole monohydrochloride] and YM114 (KAE-393) [(R)-5-[(1-indolinyl)carbonyl]-4,5,6,7-tetrahydro-1H- benzimidazole monohydrochloride] on the von Bezold-Jarisch reflex (BJR) induced by 2-methyl-5-HT, a selective serotonin (5-HT)3-receptor agonist; veratridine, which stimulates chemoreceptors and baroreceptors; and electrical stimulation of vagal efferent nerves in anesthetized rats. Results were compared with those of ondansetron and granisetron. 2-Methyl- 5-HT (5-160 micrograms/kg, i.v.) and veratridine (100-200 micrograms/kg, i.v.) dose-dependently decreased the heart rate (BJR). YM060, YM114, ondansetron and granisetron dose-dependently inhibited 2-methyl-5-HT (40 micrograms/kg, i.v.)-induced BJR, with ID50 values of 0.012, 0.060, 0.97 and 0.15 microgram/kg, i.v., respectively. Their 5-HT3 receptor blocking potencies against 2-methyl-5-HT-induced BJR were largely consistent with those against 5-HT-induced BJR. In contrast, higher doses (100 micrograms/kg, i.v.) of YM060, YM114, ondansetron and granisetron did not inhibit veratridine (150 micrograms/kg, i.v.)-induced BJR. Atropine (300 micrograms/kg, i.v.) abolished bradycardia induced by electrical stimulation of vagal efferent nerves, whereas YM060, YM114, ondansetron and granisetron had no effect at a dose of 1000 micrograms/kg, i.v. 5-HT (0.625-5.0 micrograms) injected into the left ventricle also caused a dose-dependent decrease in heart rate, an effect that was abolished by YM060 (0.1 microgram/kg, i.v.), atropine (100 micrograms/kg, i.v.) and vagotomy. These results suggest that YM060 and YM114 are highly potent and selective 5-HT3-receptor antagonists that do not affect veratridine- or electrical stimulation-induced bradycardia in anesthetized rats. They also suggest that 5-HT-induced BJR in anesthetized rats originates from 5-HT3 receptors located on the endings of vagal afferent nerves in the heart.
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PMID:Characteristics of inhibitory effects of serotonin (5-HT)3-receptor antagonists, YM060 and YM114 (KAE-393), on the von Bezold-Jarisch reflex induced by 2-Methyl-5-HT, veratridine and electrical stimulation of vagus nerves in anesthetized rats. 878 38

1. We tested the hypothesis that activation of P2X receptors associated with vagal afferent nerves can evoke a Bezold-Jarisch (B-J) depressor reflex in anaesthetized rats. 2. Injection of alphabeta-methylene ATP (alphabeta-MeATP; 0.6-600 nmol i.v.) evoked a dose-dependent B-J reflex comprising bradycardia, hypotension and apnoea in rats anaesthetized with pentobarbitone. Apnoea was commonly preceded by hyperventilation. Bilateral vagotomy significantly reduced the bradycardia and most of the apnoeic response without affecting hyperventilation, and unmasked a vasopressor response. Hypotension and apnoea were subject to desensitization, and ATP was about 100 times less potent than alphabeta-MeATP in evoking the B-J reflex. 3. ED50 values for responses to alphabeta-MeATP were: bradycardia 14.6 +/- 3.8 nmol; apnoea 47.1 +/- 8.5 nmol; hyperventilation 23.3 +/- 6.0 nmol, n = 14. The ED50 for apnoea was significantly greater than that for bradycardia or hyperventilation (P < 0.05). Atropine (2.8 micromol (kg body wt)-1 i.v.) antagonized the reflex bradycardia and hypotension. 4. The P2 antagonists suramin (14 micromol (kg body wt)-1 i.v.) and PPADS (17 micromol (kg body wt)-1 i.v.) antagonized the bradycardic and apnoeic components of the reflex response to alphabeta-MeATP, without reducing the vasopressor or hyperventilatory responses to the agonist. 5. Recordings from vagal afferents showed that pulmonary inflation receptors were activated by alphabeta-MeATP in 62 % of units recorded (ED50 22 +/- 5 nmol) and this was blocked by PPADS (17 micromol (kg body wt)-1 i.v.); unidentified vagal afferents were also activated. 6. alphabeta-MeATP activated carotid chemoreceptor afferents (ED50 23 +/- 9 nmol), an action that was unaffected by PPADS or suramin. 7. The results support the hypothesis that P2X receptor subtypes for ATP are associated with specific sensory nerves that form part of the homeostatic mechanism for cardiovascular and respiratory regulation and these receptors therefore have physiological, pathological and therapeutic significance.
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PMID:Activation of P2X receptors for adenosine triphosphate evokes cardiorespiratory reflexes in anaesthetized rats. 950 44

We investigated the effects of bilateral injections of the GABA receptor agonists muscimol (GABA A) and baclofen (GABA B) into the nucleus tractus solitarius (NTS) on the bradycardia and hypotension induced by iv serotonin injections (5-HT, 2 microg/rat) in awake male Holtzman rats. 5-HT was injected in rats with stainless steel cannulas implanted bilaterally in the NTS, before and 5, 15, and 60 min after bilateral injections of muscimol or baclofen into the NTS. The responses to 5-HT were tested before and after the injection of atropine methyl bromide. Muscimol (50 pmol/50 nl, N = 8) into the NTS increased basal mean arterial pressure (MAP) from 115 +/- 4 to 144 +/- 6 mmHg, did not change basal heart rate (HR) and reduced the bradycardia (-40 +/- 14 and -73 +/- 26 bpm at 5 and 15 min, respectively, vs -180 +/- 20 bpm for the control) and hypotension (-11 +/- 4 and -14 +/- 4 mmHg, vs -40 +/- 9 mmHg for the control) elicited by 5-HT. Baclofen (12.5 pmol/50 nl, N = 7) into the NTS also increased basal MAP, but did not change basal HR, bradycardia or hypotension in response to 5-HT injections. Atropine methyl bromide (1 mg/kg body weight) injected iv reduced the bradycardic and hypotensive responses to 5-HT injections. The stimulation of GABA A receptors in the NTS of awake rats elicits a significant increase in basal MAP and decreases the cardiac Bezold-Jarisch reflex responses to iv 5-HT injections.
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PMID:The bradycardic and hypotensive responses to serotonin are reduced by activation of GABAA receptors in the nucleus tractus solitarius of awake rats. 1600 84

We report a patient who developed cardiac asystole, which may have been caused by Bezold-Jarisch reflex as a result of hypovolemia and compression of the inferior vena cava by a huge pyometra. A 61-year-old woman with a huge pyometra with occasional supine hypotension, tachycardia, and oliguria was scheduled for removal of the tumor. The systolic blood pressure decreased from 80 mmHg to 55 mmHg with simultaneous development of bradycardia 5 minutes after incision of the abdominal wall. Atropine was given but cardiac asystole occurred. Intravenous epinephrine restored systemic blood pressure and heart beats. There was no postoperative cardiorespiratory complication.
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PMID:[Bradycardia and cardiac asystole immediately after abdominal incision for removal of a huge pyometra]. 1713 94

We determined the sympathetic and parasympathetic control of heart rate (HR) and the sensitivity of the cardiopulmonary receptors after selective carotid and aortic denervation. We also investigated the participation of the autonomic nervous system in the Bezold-Jarish reflex after selective removal of aortic and carotid baroreceptors. Male Wistar rats (220-270 g) were divided into three groups: control (CG, N = 8), aortic denervation (AG, N = 5) and carotid denervation (CAG, N = 9). AG animals presented increased arterial pressure (12%) and HR (11%) compared with CG, while CAG animals presented a reduction in arterial pressure (16%) and unchanged HR compared with CG. The sequential blockade of autonomic effects by atropine and propranolol indicated a reduction in vagal function in CAG (a 50 and 62% reduction in vagal effect and tonus, respectively) while AG showed an increase of more than 100% in sympathetic control of HR. The Bezold-Jarish reflex was evaluated using serotonin, which induced increased bradycardia and hypotension in AG and CAG, suggesting that the sensitivity of the cardiopulmonary reflex is augmented after selective denervation. Atropine administration abolished the bradycardic responses induced by serotonin in all groups; however, the hypotensive response was still increased in AG. Although the responses after atropine were lower than the responses before the drug, indicating a reduction in vagal outflow after selective denervation, our data suggest that both denervation procedures are associated with an increase in sympathetic modulation of the vessels, indicating that the sensitivity of the cardiopulmonary receptors was modulated by baroreceptor fibers.
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PMID:Effect of carotid and aortic baroreceptors on cardiopulmonary reflex: the role of autonomic function. 2062 58


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