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Medical Acupuncture Apr 2019Acupuncture has been used for treating gastrointestinal (GI) disorders such as postoperative nausea and vomiting. Electroacupuncture (EA) accelerates GI transit...
Acupuncture has been used for treating gastrointestinal (GI) disorders such as postoperative nausea and vomiting. Electroacupuncture (EA) accelerates GI transit following surgery and ameliorates postoperative ileus (POI) to restore colonic transit (CT); however, the mechanisms of this EA-induced restoration remain unclear. The aims of this study were to show CT following surgery and the effects of EA at ST 36 on POI induced by surgical stress (SS) in 45 conscious, male Sprague-Dawley rats. An operation was performed in each rat, setting a cannula into the cecum to connect the proximal colon to inject markers. On the day after surgery, 20 metal radiopaque markers were administered to the proximal colon of each rat. These markers were visible throughout the GI tract on soft X-ray immediately after administration and up to 240 minutes afterward. The rats were divided into 5 groups with 9 rats in each group: (1) SS; (2) 5 days post surgery (POST-5D); (3) SS + phentolamine; (4) EA alone; and (5) EA + atropine. The EA was performed at ST 36 for 20 minutes at a frequency of 10 Hz and agents were administered in the appropriate groups before markers were administered and measurements were taken. Measurements were performed the day after surgery except in the POST 5-D group. CT was calculated by the geometric center on the images showing the CT for each rat. CT after surgery was delayed significantly and phentolamine accelerated CT. EA restored CT following surgery and atropine abolished the effect of EA on CT. The current study demonstrated that surgery induced a delay in CT through the sympathetic pathway via α-adrenoreceptors; CT was restored by EA. These results suggest that EA can be used to treat POI through mediation of the autonomic nervous system.
PubMed: 31031877
DOI: 10.1089/acu.2018.1322 -
World Journal of Gastroenterology Jun 2017To measure exogenous corticotropin-releasing factor (CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on...
AIM
To measure exogenous corticotropin-releasing factor (CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on CRF-induced motility.
METHODS
The isolated vascularly-perfused rat colon was used. Luminal pressure was monitored microtip catheter pressure transducers in the proximal and distal colon. At first, exogenous CRF was administered in a stepwise manner and the concentration of CRF yielding maximal colonic motility was selected. After recording basal colonic motility, hexamethonium, phentolamine, propranolol, atropine and tetrodotoxin were infused into the isolated colon. Initially, only the test drug was infused; then, CRF was added. The motility index was expressed as percentage change over basal level.
RESULTS
Administration of 1.4, 14.4, 144 and 288 pmol/L CRF progressively increased colonic motility in the proximal and distal colon. Infusion of atropine or tetrodotoxin reduced CRF-induced motility of both the proximal and distal colon, whereas hexamethonium, phentolamine and propranolol had no effect.
CONCLUSION
CRF-induced colonic motility appears to be mediated by local cholinergic signaling muscarinic receptors. Muscarinic receptors are potential targets for counteracting CRF-induced colonic hypermotility.
Topics: Animals; Atropine; Colon; Corticotropin-Releasing Hormone; Gastrointestinal Motility; Male; Models, Animal; Rats; Rats, Sprague-Dawley; Receptors, Muscarinic; Tetrodotoxin
PubMed: 28638222
DOI: 10.3748/wjg.v23.i21.3825 -
Journal of Investigational Allergology... 2015Nasal hyperreactivity is the abnormal reaction of nasal tissue to a stimulus that is innocuous to most people. This response is caused by dysregulation of the autonomic... (Review)
Review
Nasal hyperreactivity is the abnormal reaction of nasal tissue to a stimulus that is innocuous to most people. This response is caused by dysregulation of the autonomic nervous system at various levels of the nasal autonomic reflex arc. Various stimuli (methacholine, histamine, adenosine 5'-monophosphate, cold air, mannitol, rapsaicin, phentolamine, and distilled water) have been used in an attempt to find the test that most reliably differentiates between healthy individuals and patients and also between different types of rhinitis. Despite the small number of publications available, in the present review, we provide an update on current nonspecific nasal provocation techniques. The studies published to date are not comparable: the stimuli applied act through different mechanisms and are used to assess different pathways, and the methodologies differ in terms of selection of participants, concentrations used, and assessment of response (criteria for positivity). Given the limited use of nonspecific nasal provocation tests in routine clinical practice, we believe that more studies are warranted to address the research issues we present at the end of the present review, for example, the need to standardize the methodology for each test or even the clinical benefits of knowing whether or not a patient has nasal hyperreactivity.
Topics: Histamine; Humans; Methacholine Chloride; Nasal Provocation Tests; Rhinitis, Allergic
PubMed: 26817136
DOI: No ID Found -
Cardiovascular and Interventional... Dec 2023To describe a novel technique of transvenous radiofrequency catheter ablation of an aldosterone-producing adenoma (APA) of the left adrenal gland using the GOS System...
PURPOSE
To describe a novel technique of transvenous radiofrequency catheter ablation of an aldosterone-producing adenoma (APA) of the left adrenal gland using the GOS System (Japan Lifeline, Tokyo, Japan). Using the GOS system, a flexible radiofrequency tip catheter can be inserted into the adrenal central and tributary veins, the drainers for functional tumors.
MATERIALS AND METHODS
An APA at the left adrenal gland, which was diagnosed by segmental adrenal venous sampling following administration of 0.25 mg cosyntropin, was ablated using the GOS catheter inserted into adrenal tributary veins via a right femoral vein 7-Fr sheath. The effect of radiofrequency ablation on APA was assessed using the international consensus on surgical outcomes for unilateral primary aldosteronism (PA).
RESULTS
No device-related complications were observed. The patient was deeply sedated under blood pressure and heart rate control with continuous administration of β-blockers. Then, the tumor and surrounding adrenal gland were cauterized at 7000 J two times each in sequence. The output time was 7-11 min for each ablation and 80 min in total. For blood pressure and pulse rate control, esmolol hydrochloride and phentolamine mesylate were used. The contrast enhancement of APA disappeared on dynamic CT immediately after the procedure. PA was biochemically cured until 12 months after the procedure.
CONCLUSION
Using the radiofrequency device with the GOS catheter and system is a method for cauterizing adrenal tumors from blood vessels. This approach resulted in a marked reduction in aldosterone concentrations and a complete biochemical cure of PA over the observation period.
Topics: Humans; Aldosterone; Adrenal Glands; Adrenal Gland Neoplasms; Catheters; Catheter Ablation; Hyperaldosteronism
PubMed: 37973663
DOI: 10.1007/s00270-023-03584-x -
Frontiers in Physiology 2018Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we...
Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest.
Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients.
PubMed: 29487541
DOI: 10.3389/fphys.2018.00099 -
BMC Endocrine Disorders Jul 2022Ectopic ACTH-dependent Cushing syndrome is rarely caused by pheochromocytoma (PCC). Glucocorticoid-regulated positive feedback loops in ACTH and catecholamines were...
BACKGROUND
Ectopic ACTH-dependent Cushing syndrome is rarely caused by pheochromocytoma (PCC). Glucocorticoid-regulated positive feedback loops in ACTH and catecholamines were proposed in some similar cases.
CASE PRESENTATION
We present here an 80-year-old man who had previously undergone surgery for a left adrenal PCC and newly developed severe hypertension, hypokalemia, and typical Cushingoid manifestations. Investigations revealed hyperglycemia, hypokalemia, and extremely high catecholamines and their metabolites, ACTH and cortisol. Imaging modalities showed a recurrent large left adrenal mass positively visualized with I-metaiodobenzylguanidine as well as somatostatin receptor scintigraphy. Surgical interventions were not indicated; thus, metyrapone, phentolamine, and doxazocin were initiated, which successfully controlled his symptoms and biochemical conditions. With the evidence that metyrapone administration decreased ACTH and catecholamine levels, the existence of positive feedback loops was speculated. During the terminal stages of the disease, additional metyrosine treatment successfully stabilized his physiological and biochemical conditions. Upon the patient's death, pathological autopsy was performed. Immunohistochemical analysis indicated that the tumor appeared to be co-positive with tyrosine hydroxylase (TH) as well as ACTH in most tumor cells in both PCC and liver metastasis. Most cells were clearly positive for somatostatin receptor 2 staining in the membrane compartment. The dense immunostaining of ACTH, TH, dopamine-β-hydroxylase and the large tumor size with positive feedback loops may be correlated with high levels of ACTH and catecholamines in the circulation.
CONCLUSIONS
We experienced a case of severe ectopic ACTH producing the largest reported recurrent malignant left PCC with liver metastases that presented positive feedback loops in the ACTH/cortisol and catecholamine/cortisol axes. Clinicians should be aware of the paradoxical response of ACTH on metyrapone treatment and possible steroid-induced catecholamine crisis.
Topics: ACTH Syndrome, Ectopic; Adrenal Gland Neoplasms; Adrenocorticotropic Hormone; Aged, 80 and over; Catecholamines; Humans; Hydrocortisone; Hypokalemia; Male; Metyrapone; Neoplasm Recurrence, Local; Neuroendocrine Tumors; Pheochromocytoma
PubMed: 35854271
DOI: 10.1186/s12902-022-01090-8 -
Experimental and Therapeutic Medicine Apr 2017The aim of this study was to examine the effects of phentolamine on severe hand, foot and mouth disease (HFMD) combined with pulmonary edema (PE). From May 2008 to...
The aim of this study was to examine the effects of phentolamine on severe hand, foot and mouth disease (HFMD) combined with pulmonary edema (PE). From May 2008 to December 2012, 53 children with severe HFMD plus PE were enrolled in the treatment group, receiving phentolamine intravenously at a loading dose of 5 µg/kg/min. The control group comprised 52 children with the same disease who did not receive phentolamine infusion. Data concerning creatine kinase (CK), CK-MB, cardiac troponin I (cTnI), heart rate, systolic blood pressure (SBP) and the duration of ventilation dependence and hospitalization were collected. Adverse events were also recorded. It was found that the phentolamine-treated patients exhibited significantly lower CK, CK-MB and cTnI levels, heart rate and SBP than the controls (P<0.01 for all parameters). The average duration of ventilator dependence and hospitalization was significantly shorter (P<0.01) in the phentolamine group than in the control group. It was also found that the overall mortality rate was lower in the phentolamine group (5.8%) than in the control group (11.5%). No adverse events were observed in either group. Thus, these results offer preliminary evidence that phentolamine reduces mortality and relieves the symptoms of EV71-induced PE. Phentolamine is a potential therapeutic agent for this highly lethal disorder.
PubMed: 28413485
DOI: 10.3892/etm.2017.4104 -
Psychosomatic Medicine Sep 2018Acute stress induces redistribution of circulating leucocytes in humans. Although effects on lymphocytes as adaptive immune cells are well understood, the mechanisms...
OBJECTIVE
Acute stress induces redistribution of circulating leucocytes in humans. Although effects on lymphocytes as adaptive immune cells are well understood, the mechanisms underlying stress effects on granulocytes and monocytes as innate immune blood cells are still elusive. We investigated whether the stress hormone norepinephrine (NE) and α-adrenergic receptors (α-ADRs) may play a mediating role.
METHODS
In a stress study, we cross-sectionally tested 44 healthy men for associations between stress-induced NE increases and simultaneous granulocyte and monocyte cell count increases, as measured immediately before and several times after the Trier Social Stress Test. In a subsequent infusion study, 21 healthy men participated in three different experimental trials with sequential infusions of 1- and 15-minute duration with varying substances (saline as placebo, the nonspecific α-ADR blocker phentolamine [2.5 mg/min], and NE [5 μg/min]): trial 1 = saline+saline, trial 2 = saline+NE, trial 3 = phentolamine+NE. Granulocyte and monocyte cell numbers were assessed before, immediately after, 10 minutes, and 30 minutes after infusion procedures.
RESULTS
In the stress study, higher NE related to higher neutrophil stress changes (β = .31, p = .045, R change = .09), but not epinephrine stress changes. In the infusion study, saline+NE induced significant increases in neutrophil (F(3/60) = 43.50, p < .001, η = .69) and monocyte (F(3/60) = 18.56, p < .001, η = .48) numbers compared with saline+saline. With phentolamine+NE, neutrophil (F(3/60) = 14.41, p < .001, η = .42) and monocyte counts (F(2.23/44.6) = 4.32, p = .016, η = .18) remained increased compared with saline+saline but were lower compared with saline+NE (neutrophils: F(3/60) = 19.55, p < .001, η = .494, monocytes: F(3/60) = 2.54, p = .065, η = .11) indicating partial mediation by α-ADRs. Trials did not differ in eosinophil and basophil count reactivity.
CONCLUSIONS
Our findings suggest that NE-induced immediate increases in neutrophil and monocyte numbers resemble psychosocial stress effects and can be reduced by blockade of α-ADRs.
Topics: Adrenergic alpha-Antagonists; Adult; Aged; Cross-Sectional Studies; Granulocytes; Humans; Male; Middle Aged; Monocytes; Norepinephrine; Phentolamine; Receptors, Adrenergic, alpha; Stress, Psychological; Young Adult
PubMed: 29965944
DOI: 10.1097/PSY.0000000000000620 -
International Journal of Molecular... Jun 2023This study aimed to elucidate the vasodilatory effects and cytotoxicity of various vasodilators used as antispasmodic agents during microsurgical anastomosis. Rat smooth...
This study aimed to elucidate the vasodilatory effects and cytotoxicity of various vasodilators used as antispasmodic agents during microsurgical anastomosis. Rat smooth muscle cells (RSMCs) and human coronary artery endothelial cells (HCAECs) were used to investigate the physiological concentrations and cytotoxicity of various vasodilators (lidocaine, papaverine, nitroglycerin, phentolamine, and orciprenaline). Using a wire myograph system, we determined the vasodilatory effects of each drug in rat abdominal aortic sections at the concentration resulting in maximal vasodilation as well as at the surrounding concentrations 10 min after administration. Maximal vasodilation effect 10 min after administration was achieved at the following concentrations: lidocaine, 35 mM; papaverine, 0.18 mM; nitroglycerin, 0.022 mM; phentolamine, 0.11 mM; olprinone, 0.004 mM. The IC for lidocaine, papaverine, and nitroglycerin was measured in rat abdominal aortic sections, as well as in RSMCs after 30 min and in HCAECs after 10 min. Phentolamine and olprinone showed no cytotoxicity towards RSMCs or HCAECs. The concentrations of the various drugs required to achieve vasodilation were lower than the reported clinical concentrations. Lidocaine, papaverine, and nitroglycerin showed cytotoxicity, even at lower concentrations than those reported clinically. Phentolamine and olprinone show antispasmodic effects without cytotoxicity, making them useful candidates for local administration as antispasmodics.
Topics: Humans; Rats; Animals; Parasympatholytics; Papaverine; Nitroglycerin; Phentolamine; Endothelial Cells; Microsurgery; Muscle, Smooth, Vascular; Vasodilator Agents; Vasodilation; Myocytes, Smooth Muscle; Lidocaine
PubMed: 37446027
DOI: 10.3390/ijms241310850 -
International Journal of Molecular... Dec 2020The catecholamines norepinephrine and epinephrine are important regulators of vertebrate physiology. Insects such as honeybees do not synthesize these neuroactive...
The catecholamines norepinephrine and epinephrine are important regulators of vertebrate physiology. Insects such as honeybees do not synthesize these neuroactive substances. Instead, they use the phenolamines tyramine and octopamine for similar physiological functions. These biogenic amines activate specific members of the large protein family of G protein-coupled receptors (GPCRs). Based on molecular and pharmacological data, insect octopamine receptors were classified as either α- or β-adrenergic-like octopamine receptors. Currently, one α- and four β-receptors have been molecularly and pharmacologically characterized in the honeybee. Recently, an α-adrenergic-like octopamine receptor was identified in (DmOctα2R). This receptor is activated by octopamine and other biogenic amines and causes a decrease in intracellular cAMP ([cAMP]). Here, we show that the orthologous receptor of the honeybee (AmOctα2R), phylogenetically groups in a clade closely related to human α-adrenergic receptors. When heterologously expressed in an eukaryotic cell line, AmOctα2R causes a decrease in [cAMP]. The receptor displays a pronounced preference for octopamine over tyramine. In contrast to DmOctα2R, the honeybee receptor is not activated by serotonin. Its activity can be blocked efficiently by 5-carboxamidotryptamine and phentolamine. The functional characterization of AmOctα2R now adds a sixth member to this subfamily of monoaminergic receptors in the honeybee and is an important step towards understanding the actions of octopamine in honeybee behavior and physiology.
Topics: Adenylyl Cyclases; Animals; Bees; Insect Proteins; Octopamine; Phentolamine; Protein Binding; Receptors, Biogenic Amine; Sequence Homology; Serotonin; Substrate Specificity
PubMed: 33302363
DOI: 10.3390/ijms21249334