scholarly journals The basal release of endothelium-derived catecholamines regulates the contractions of Chelonoidis carbonaria aorta caused by electrical-field stimulation

Biology Open ◽  
2020 ◽  
pp. bio.057042
Author(s):  
José Britto-Júnior ◽  
Felipe Fernandes Jacintho ◽  
Rafael Campos ◽  
David Halen Araújo Pinheiro ◽  
Guilherme M. Figueiredo Murari ◽  
...  
Keyword(s):  
Sch 23390 ◽  
Flow Distribution ◽  
Electrical Field Stimulation ◽  
Organ Blood Flow ◽  
Field Stimulation ◽  
Receptor Antagonists ◽  
Synthesis Inhibitor ◽  
Electrical Field ◽  
Voltage Gated Sodium Channels ◽  
Noradrenaline And Adrenaline

The contractions of Chelonoidis carbonaria aortic rings induced by electrical field stimulation (EFS) are not inhibited by blockade of the voltage-gated sodium channels by tetrodotoxin but almost abolished by the α1/α2-adrenoceptor antagonist phentolamine. The objective of this study was to identify the mediator(s) responsible for the EFS-induced contractions of Chelonoidis carbonaria aortic rings. Each ring was suspended between two wire hooks and mounted in isolated 10 mL organ chambers filled with oxygenated and heated Krebs-Henseleit's solution. Dopamine, noradrenaline and adrenaline concentrations were analysed by liquid chromatography coupled to tandem mass spectrometry. The contractions caused by dopamine and EFS were done in absence and presence of the nitric oxide (NO) synthesis inhibitor L-NAME, the NO-sensitive guanylyl cyclase inhibitor ODQ, the D1-like receptor antagonist SCH-23390, the D2-like receptor antagonists risperidone, quetiapine, haloperidol, and the tyrosine hydroxylase inhibitors salsolinol and 3-iodo-L-tyrosine. Basal concentrations of dopamine, noradrenaline and adrenaline were detected in Krebs-Henseleit solution containing the aortic rings. The catecholamine concentrations were significantly reduced in endothelium-denuded aortic rings. L-NAME and ODQ significantly potentiated the dopamine-induced contractions. The D2-like receptor antagonists inhibited the EFS-induced contractions of the aortic rings treated with L-NAME, whereas SCH 23390 had no effect. Similar results were observed in the contractions induced by dopamine in L-NAME treated aortic rings. These results indicate that catecholamines released by endothelium regulate the EFS-induced contractions. This may constitute a suitable mechanism by which reptilia modulate specific organ blood flow distribution.

scholarly journals Orchidectomy increases the formation of non-endothelial thromboxane A2 and modulates its role in the electrical field stimulation-induced response in rat mesenteric artery

2008 ◽  
Vol 197 (2) ◽  
pp. 371-379 ◽  
Author(s):  
L del Campo ◽  
A Sagredo ◽  
R Aras-López ◽  
G Balfagón ◽  
M Ferrer
Keyword(s):  
Electrical Field Stimulation ◽  
Mesenteric Arteries ◽  
Induced Response ◽  
Field Stimulation ◽  
Sprague Dawley ◽  
Synthesis Inhibitor ◽  
Electrical Field ◽  
Rat Mesenteric Artery ◽  
No Release ◽  
Male Sex

The aim of this study was to analyze whether endogenous male sex hormones influence the release of thromboxane A2 (TXA2) and its role in the electrical field stimulation (EFS)-induced response, as well as the mechanism involved. For this purpose, endothelium-denuded mesenteric arteries from control and orchidectomized male Sprague–Dawley rats were used to measure TXA2 release; EFS-induced response, nitric oxide (NO), norepinephrine (NA), and prostaglandin (PG) I2 release were also measured in the presence of the TXA2 synthesis inhibitor furegrelate. Orchidectomy increased basal and EFS-induced TXA2 release. Furegrelate decreased the EFS-induced contraction in arteries from control rats, but did not modify it in arteries from orchidectomized rats. The EFS-induced neuronal NO release and vasodilator response were increased by furegrelate in arteries from control rats, but were not modified in arteries from orchidectomized rats. Furegrelate did not modify the EFS-induced NA release or vasoconstrictor response in arteries from either control or orchidectomized rats. The EFS-induced PGI2 release was not modified by furegrelate in arteries from control rats, but was increased in arteries from orchidectomized rats. The results of the present study show that endogenous male sex hormone deprivation i) increases non-endothelial TXA2 release and ii) regulates the effect of endogenous TXA2 on the EFS-induced response through different mechanisms that, at the least, involve the NO and PGI2 systems. In arteries from control rats, inhibition of TXA2 formation decreases the EFS-induced response by increasing neuronal NO release. In arteries from orchidectomized rats, the EFS-induced response is unaltered after the inhibition of TXA2 formation, by increasing PGI2 release.

scholarly journals β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum

2015 ◽  
Vol 308 (11) ◽  
pp. G955-G963 ◽  
Author(s):  
Guo-Du Wang ◽  
Xi-Yu Wang ◽  
Sumei Liu ◽  
Yun Xia ◽  
Fei Zou ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Nicotinamide Adenine Dinucleotide ◽  
Neuromuscular Junctions ◽  
Electrical Field Stimulation ◽  
Nicotinamide Adenine ◽  
Muscle Membrane ◽  
Receptor Subtype ◽  
Field Stimulation ◽  
Receptor Antagonists ◽  
Electrical Field

Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro- N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro- N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions.

Further studies on the motor response of the human isolated urinary bladder to tachykinins, capsaicin and electrical field stimulation

1989 ◽  
Vol 20 (5) ◽  
pp. 663-669 ◽  
Author(s):  
Carlo Alberto Maggi ◽  
Riccardo Patacchini ◽  
Paolo Santicioli ◽  
Damiano Turini ◽  
Gabriele Barbanti ◽  
...  
Keyword(s):  
Urinary Bladder ◽  
Motor Response ◽  
Electrical Field Stimulation ◽  
Field Stimulation ◽  
Electrical Field

Pharmacologic responses of the mouse urinary bladder

Open Medicine ◽  
2009 ◽  
Vol 4 (2) ◽  
pp. 192-197 ◽  
Author(s):  
A. Canda ◽  
Christopher Chapple ◽  
Russ Chess-Williams
Keyword(s):  
Nitric Oxide ◽  
Urinary Bladder ◽  
Electrical Field Stimulation ◽  
Inhibitory Effect ◽  
Minor Role ◽  
Detrusor Muscle ◽  
Field Stimulation ◽  
Muscarinic Agonists ◽  
Electrical Field ◽  
M3 Receptor

AbstractThe aim of the study was to determine pathways involved in contraction and relaxation of the mouse urinary bladder. Mouse bladder strips were set up in gassed Krebs-bicarbonate solution and responses to various drugs and electrical field stimulation were obtained. Isoprenaline (b-receptor agonist) caused a 63% inhibition of carbachol precontracted detrusor (EC50=2nM). Carbachol caused contraction (EC50=0.3µM), responses were antagonised more potently by 4-DAMP (M3-antagonist) than methoctramine (M2-antagonist). Electrical field stimulation caused contraction, which was inhibited by atropine (60%) and less by guanethidine and α,β-methylene-ATP. The neurogenic responses were not potentiated by inhibition of nitric oxide synthase. Presence of an intact urothelium significantly depressed responses to carbachol (p=0.02) and addition of indomethacin and L-NNA to remove prostaglandin and nitric oxide production respectively did not prevent the inhibitory effect of the urothelium. In conclusion, b-receptor agonists cause relaxation and muscarinic agonists cause contraction via the M3-receptor. Acetylcholine is the main neurotransmitter causing contraction while nitric oxide has a minor role. The mouse and human urothelium are similar in releasing a factor that inhibits contraction of the detrusor muscle which is unidentified but is not nitric oxide or a prostaglandin. Therefore, the mouse may be used as a model to study the lower urinary tract.

Treatment of gastric ulcers and diarrhea with the Amazonian herbal medicine sangre de grado

2000 ◽  
Vol 279 (1) ◽  
pp. G192-G200 ◽  
Author(s):  
Mark J. S. Miller ◽  
Wallace K. MacNaughton ◽  
Xiao-Jing Zhang ◽  
Jane H. Thompson ◽  
Randi M. Charbonnet ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Cost Effective ◽  
Electrical Field Stimulation ◽  
Skin Lesions ◽  
Gastric Ulcers ◽  
Myeloperoxidase Activity ◽  
Field Stimulation ◽  
Electrical Field ◽  
Ussing Chambers ◽  
Cost Effective Treatment

Sangre de grado is an Amazonian herbal medicine used to facilitate the healing of gastric ulcers and to treat gastritis, diarrhea, skin lesions, and insect stings. This study was designed to evaluate the gastrointestinal applications. Gastric ulcers were induced in rats by brief serosal exposure of the fundus to acetic acid (80%). Sangre de grado was administered in drinking water at 1:1,000 and 1:10,000 dilutions from the postoperative period to day 7. Guinea pig ileum secretory responses to capsaicin, electrical field stimulation, and the neurokinin-1 (NK-1) agonist [Sar9,Met(O2)11]substance P were examined in Ussing chambers. Sangre de grado facilitated the healing of experimental gastric ulcer, reducing myeloperoxidase activity, ulcer size, and bacterial content of the ulcer. The expression of proinflammatory genes tumor necrosis factor-α, inducible nitric oxide synthase (iNOS), interleukin (IL)-1β, IL-6, and cyclooxygenase-2 was upregulated by ulcer induction but reduced by sangre de grado treatment, particularly iNOS and IL-6. In Ussing chambers, sangre de grado impaired the secretory response to capsaicin but not to electrical field stimulation or the NK-1 agonist. We conclude that sangre de grado is a potent, cost-effective treatment for gastrointestinal ulcers and distress via antimicrobial, anti-inflammatory, and sensory afferent-dependent actions.

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