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https://www.readbyqxmd.com/read/29351439/role-of-reactive-oxygen-species-and-sulfide-quinone-oxoreductase-in-hydrogen-sulfide-induced-contraction-of-rat-pulmonary-arteries
#1
Jesus Prieto-Lloret, Vladimir A Snetkov, Yasin Shaifta, Inmaculada Docio, Michelle J Connolly, Charles E Mackay, Greg A Knock, Jeremy Pt Ward, Philip I Aaronson
Application of H2S ('sulfide') elicits a complex contraction in rat pulmonary arteries (PA) comprising a small transient contraction (phase 1; Ph1) followed by relaxation and then a second, larger, and more sustained contraction (phase 2; Ph2). We investigated the mechanisms causing this response using isometric myography in rat second order PA, with Na2S as a sulfide donor. Both phases of contraction to 1000μM Na2S were attenuated by the pan-PKC inhibitor Gö6983 (3μM) and by 50μM ryanodine; the Ca2+ channel blocker nifedipine (1μM) was without effect...
December 28, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
https://www.readbyqxmd.com/read/29348090/pharmacological-validation-of-the-folkloric-uses-of-cyperus-rotundus-l-in-different-ailments-an-in-vivo-and-in-vitro-research
#2
Musaddique Hussain, Hafiz Muhammad Waqas, Ikhlaq Hussain, Abdul Majeed, Shahid Masood Raza, Khalid Hussain Janbaz
In vivo and in vitro research study was conducted on Cyperus rotundus to evaluate the sound mechanistic background in the treatment of gastrointestinal, bronchial and vascular disorders as well as in pain, emesis, pyrexia and bacterial infections. Results showed that crude extract of Cyperus rotundus (Cr.Cr) exhibited the dose-dependent spasmolytic effect in rabbit jejunum by inhibiting the spontaneous and K+ (80 mM)-induced contractions. Pretreatment of tissue with Cr. Cr caused the rightward shift of calcium concentration response curves, similar to verapamil...
January 2018: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/29337194/fasudil-ameliorates-the-ischemia-reperfusion-oxidative-injury-in-rat-hearts-through-suppression-of-myosin-regulatory-light-chain-nadph-oxidase-2-pathway
#3
Yi-Shuai Zhang, Li-Jing Tang, Hua Tu, Shi-Jing Wang, Bin Liu, Xiao-Jie Zhang, Nian-Sheng Li, Xiu-Ju Luo, Jun Peng
Fasudil is a potent Rho-kinase (ROCK) inhibitor and can relax smooth muscle or cardiac muscle contraction through decreasing the phosphorylation level of myosin regulatory light chain (p-MLC20 or p-MLC2v), while p-MLC2v can function as a transcription factor to promote the NADPH oxidase 2 (NOX2) expression in rat hearts subjected to ischemia/reperfusion (I/R). This study aims to explore whether fasudil can protect the rat hearts against I/R oxidative injury through suppressing NOX2 expression via reduction of p-MLC2v level...
January 11, 2018: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29334582/carbohydrate-mouth-rinsing-does-not-prevent-the-decline-in-maximal-strength-following-fatiguing-exercise
#4
Christopher D Black, Daniel J Schubert, Marcin K Szczyglowski, Joshua D Wren
Carbohydrate (CHO) rinsing has been shown to attenuate the decline of maximal voluntary contractions (MVC) following fatiguing exercise-perhaps via a central mechanism. This study sought to determine the effect of a CHO rinse on MVC, voluntary activation, and contractile properties following fatiguing exercise. Thirteen adults participated in a double-blind, cross-over study. MVC of the dominant knee extensors was assessed and voluntary activation (%VA) was determined using twitch-interpolation. Participants then held 50% of MVC until volitional fatigue followed by a 20s rinse with a solution of 8% maltodextrin (CHO) or placebo (PLA)...
January 12, 2018: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/29318030/environmental-temperature-and-exercise-modality-independently-impact-central-and-muscle-fatigue-among-people-with-multiple-sclerosis
#5
Geetika Grover, Michelle Ploughman, Devin T Philpott, Liam P Kelly, Augustine J Devasahayam, Katie Wadden, Kevin E Power, Duane C Button
Background: Heat sensitivity and fatigue limit the ability of multiple sclerosis patients to participate in exercise. Objective: The purpose of this study was to determine the optimal aerobic exercise parameters (environmental temperature and exercise modality) to limit exercise-induced central and muscle fatigue among people with multiple sclerosis. Methods: Fourteen people with multiple sclerosis with varying levels of disability completed four randomized exercise sessions at 65% of the maximal volume of oxygen: body-weight supported treadmill cool (16°C), body-weight supported treadmill room (21°C), total-body recumbent stepper cool and total-body recumbent stepper room...
October 2017: Multiple Sclerosis Journal—Experimental, Translational and Clinical
https://www.readbyqxmd.com/read/29317262/sensitivity-to-strain-and-shear-stress-of-isolated-mechanosensitive-enteric-neurons
#6
Eva Maria Kugler, Klaus Michel, David Kirchenbüchler, Georg Dreissen, Agnes Csiszár, Rudolf Merkel, Michael Schemann, Gemma Mazzuoli-Weber
Within the enteric nervous system, the neurons in charge to control motility of the gastrointestinal tract reside in a particular location nestled between two perpendicular muscle layers which contract and relax. We used primary cultured myenteric neurons of male guinea pigs to study mechanosensitivity of enteric neurons in isolation. Ultrafast Neuroimaging with a voltage sensitive dye technique was used to record neuronal activity in response to shear stress and strain. Strain was induced by locally deforming the elastic cell culture substrate next to a neuron...
January 6, 2018: Neuroscience
https://www.readbyqxmd.com/read/29315829/effects-of-acute-isometric-resistance-exercise-on-cervicomedullary-motor-evoked-potentials
#7
James L Nuzzo, Benjamin K Barry, Simon C Gandevia, Janet L Taylor
Cervicomedullary motor evoked potentials (CMEPs) in relaxed biceps brachii have been reported to facilitate after acute isometric exercise of the elbow flexors. This facilitation, which reflects either enhanced corticospinal transmission or increased motoneurone excitability, has only been documented in the limb posture used during exercise. In Experiment 1, we tested if these spinal changes "transfer" to a second posture. Fourteen individuals completed 12 sets of high-force isometric contractions of the elbow flexors with the forearm pronated...
January 6, 2018: Scandinavian Journal of Medicine & Science in Sports
https://www.readbyqxmd.com/read/29305679/decreased-coronary-arteriolar-response-to-kca-channel-opener-after-cardioplegic-arrest-in-diabetic-patients
#8
Yuhong Liu, Victoria Cole, Isabella Lawandy, Afshin Ehsan, Frank W Sellke, Jun Feng
We have recently found that diabetes is associated with the inactivation of the calcium-activated potassium channels (KCa) in endothelial cells, which may contribute to endothelial dysfunction in diabetic patients at baseline. In the current study, we further investigated the effects of diabetes on coronary arteriolar responses to the small (SK) and intermediate (IK) KCa opener NS309 in diabetic and non-diabetic patients and correlated that data with the changes in the SK/IK protein expression/distribution in the setting of cardioplegic ischemia and reperfusion (CP) and cardiopulmonary bypass (CPB)...
January 5, 2018: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/29304997/cellular-biomechanics-in-skeletal-muscle-regeneration
#9
Edward W Li, Olivia C McKee-Muir, Penney M Gilbert
Satellite cells, adult stem cells in skeletal muscle tissue, reside within a mechanically dynamic three-dimensional microenvironment. With each contraction-relaxation cycle, a satellite cell is expected to experience tensile, shear, and compressive stresses, and through cell-extracellular matrix interactions, also gauge the stiffness of the niche. Via mechanoreceptors, cells can sense these biophysical parameters of the niche, which serve to physically induce conformational changes that impact biomolecule activity, and thereby alter downstream signal transduction pathways and ultimately cell fate...
2018: Current Topics in Developmental Biology
https://www.readbyqxmd.com/read/29304939/standards-for-instrument-migration-when-implementing-paper-patient-reported-outcome-instruments-electronically-recommendations-from-a-qualitative-synthesis-of-cognitive-interview-and-usability-studies
#10
Willie Muehlhausen, Bill Byrom, Barbara Skerritt, Marie McCarthy, Bryan McDowell, Jeremy Sohn
OBJECTIVES: To synthesize the findings of cognitive interview and usability studies performed to assess the measurement equivalence of patient-reported outcome (PRO) instruments migrated from paper to electronic formats (ePRO), and make recommendations regarding future migration validation requirements and ePRO design best practice. METHODS: We synthesized findings from all cognitive interview and usability studies performed by a contract research organization between 2012 and 2015: 53 studies comprising 68 unique instruments and 101 instrument evaluations...
January 2018: Value in Health: the Journal of the International Society for Pharmacoeconomics and Outcomes Research
https://www.readbyqxmd.com/read/29301136/assessment-of-the-airway-smooth-muscle-relaxant-effect-of-drotaverine
#11
Zoltán Patai, András Guttman, Endre G Mikus
BACKGROUND: Drotaverine, a type 4 cyclic nucleotide phosphodiesterase (PDE4) inhibitor, blocks the degradation of 3',5'-cyclic adenosine monophosphate. However, published receptor binding data showed that drotaverin also binds to the L-type voltage-operated calcium channel (L-VOCC). Based on these molecular mechanisms of action, a direct and indirect (by blocking the constrictor response) relaxant effect on airway smooth muscle can be predicted, which has not yet been assessed. SUMMARY: Accordingly, drotaverine and reference agents were tested both on the histamine-, methacholine-, or KCl-induced contraction response and on precontracted guinea pig tracheal preparations...
January 4, 2018: Pharmacology
https://www.readbyqxmd.com/read/29277716/further-investigation-of-the-effects-of-5-hydroxytryptamine-8-oh-dpat-and-doi-to-mediate-contraction-and-relaxation-responses-in-the-intestine-and-emesis-in-suncus-murinus
#12
Farideh A Javid, Saeed Afshin-Javid, Charles C Horn
5-HT receptors are implicated in many gastrointestinal disorders. However, the precise role of 5-HT in mediating GI responses in Suncus murnius is still unclear. Therefore in this study, the effects of 5-HT and its agonists were investigated in Suncus. The involvement of 5-HT2C receptors in mediating emesis was also investigated. The ability of 5-HT and its agonists/antagonists at 5-HT1A and 5-HT2 to modify GI motility was investigated in vitro and in vivo. WAY100635 (a 5-HT1A antagonist) inhibited the contraction response to 5-HT in the proximal segments without affecting the maximum response; whilst enhancing the contraction to 5-HT (>30...
December 22, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29277372/effects-of-chlorogenic-acid-on-carbachol-induced-contraction-of-mouse-urinary-bladder
#13
Takeharu Kaneda, Noriyasu Sasaki, Norimoto Urakawa, Kazumasa Shimizu
Chlorogenic acid (CGA) is a polyphenol found in coffee and medicinal herbs such as Lonicera japonica. In this study, the effect of CGA-induced relaxation on carbachol (CCh)-induced contraction of mouse urinary bladder was investigated. CGA (30-300 μg/ml) inhibited CCh- or U46619-induced contraction in a concentration-dependent manner. SQ22536 (adenylyl cyclase inhibitor) recovered CGA-induced relaxation of CCh-induced contraction; however, ODQ (guanylyl cyclase inhibitor) did not have the same effect. In addition, 3-isobutyl-1-methylxanthine (IBMX) enhanced CGA-induced relaxation; however, forskolin or sodium nitroprusside did not have the same effect...
December 15, 2017: Journal of Pharmacological Sciences
https://www.readbyqxmd.com/read/29275169/testosterone-induces-hyporesponsiveness-by-interfering-with-ip3-receptors-in-guinea-pig-airway-smooth-muscle
#14
Luis M Montaño, Edgar Flores-Soto, Jorge Reyes-García, Verónica Díaz-Hernández, Abril Carbajal-García, Elías Campuzano-González, G Lizbeth Ramírez-Salinas, Marco A Velasco-Velázquez, Bettina Sommer
Asthma symptoms have been associated with sex steroids. During childhood, this illness seems more frequent in boys than in girls and this tendency reverts in puberty when it is more severe in women. Testosterone (TES), at supraphysiological concentrations, relaxed pre-contracted airway smooth muscle, but its effects at physiological concentrations have not been thoroughly studied. We explored this possibility in guinea pig tracheal smooth muscle. In myocytes TES (10 nM) abolished carbachol (CCh)-induced intracellular Ca2+ concentration ([Ca2+]i) increment...
December 21, 2017: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/29274380/the-nox1-isoform-of-nadph-oxidase-is-involved-in-dysfunction-of-liver-sinusoids-in-nonalcoholic-fatty-liver-disease
#15
Misaki Matsumoto, Jia Zhang, Xueqing Zhang, Junjie Liu, Joy X Jiang, Kanji Yamaguchi, Akiyuki Taruno, Masato Katsuyama, Kazumi Iwata, Masakazu Ibi, Wenhao Cui, Kuniharu Matsuno, Yoshinori Marunaka, Yoshito Itoh, Natalie J Torok, Chihiro Yabe-Nishimura
The increased production of reactive oxygen species (ROS) has been postulated to play a key role in the progression of nonalcoholic fatty liver disease (NAFLD). However, the source of ROS and mechanisms underlying the development of NAFLD have yet to be established. We observed a significant up-regulation of a minor isoform of NADPH oxidase, NOX1, in the liver of nonalcoholic steatohepatitis (NASH) patients as well as of mice fed a high-fat and high-cholesterol (HFC) diet for 8 weeks. In mice deficient in Nox1 (Nox1KO), increased levels of serum alanine aminotransferase and hepatic cleaved caspase-3 demonstrated in HFC diet-fed wild-type mice (WT) were significantly attenuated...
December 20, 2017: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/29262355/regulation-of-contraction-by-the-thick-filaments-in%C3%A2-skeletal-muscle
#16
REVIEW
Malcolm Irving
Contraction of skeletal muscle cells is initiated by a well-known signaling pathway. An action potential in a motor nerve triggers an action potential in a muscle cell membrane, a transient increase of intracellular calcium concentration, binding of calcium to troponin in the actin-containing thin filaments, and a structural change in the thin filaments that allows myosin motors from the thick filaments to bind to actin and generate force. This calcium/thin filament mediated pathway provides the "START" signal for contraction, but it is argued that the functional response of the muscle cell, including the speed of its contraction and relaxation, adaptation to the external load, and the metabolic cost of contraction is largely determined by additional mechanisms...
December 19, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/29259649/chloroform-extract-of-artemisia-annua-l-relaxes-mouse-airway-smooth-muscle
#17
Jun Huang, Li-Qun Ma, Yongle Yang, Nana Wen, Wan Zhou, Congli Cai, Qing-Hua Liu, Jinhua Shen
Artemisia annua L. belongs to the Asteraceae family, which is indigenous to China. It has valuable pharmacological properties, such as antimalarial, anti-inflammatory, and anticancer properties. However, whether it possesses antiasthma properties is unknown. In the current study, chloroform extract of Artemisia annua L. (CEAA) was prepared, and we found that CEAA completely eliminated acetylcholine (ACh) or high K+-elicited (80 mM) contractions of mouse tracheal rings (TRs). Patch-clamp technique and ion channel blockers were employed to explore the underlying mechanisms of the relaxant effect of CEAA...
2017: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/29259040/small-ca2-releases-enable-hour-long-high-frequency-contractions-in-midshipman-swimbladder-muscle
#18
Frank E Nelson, Stephen Hollingworth, James O Marx, Stephen M Baylor, Lawrence C Rome
Type I males of the Pacific midshipman fish (Porichthys notatus) vibrate their swimbladder to generate mating calls, or "hums," that attract females to their nests. In contrast to the intermittent calls produced by male Atlantic toadfish (Opsanus tau), which occur with a duty cycle (calling time divided by total time) of only 3-8%, midshipman can call continuously for up to an hour. With 100% duty cycles and frequencies of 50-100 Hz (15°C), the superfast muscle fibers that surround the midshipman swimbladder may contract and relax as many as 360,000 times in 1 h...
December 19, 2017: Journal of General Physiology
https://www.readbyqxmd.com/read/29251668/perioperative-fluid-accumulation-impairs-intestinal-contractility-to-a-smilar-extent-as-peritonitis-and-endotoxemia
#19
José Gorrasi, Stephan M Jakob, Luis Tovar, Bruno Balsiger, Sebastian Brandt, Lukas E Bruegger, Hendrik Bracht, Jukka Takala
BACKGROUND: Perioperative resuscitation with large amounts of fluid may cause tissue edema, especially in the gut, and thereby impair its functions. This is especially relevant in sepsis where capillaries become leaky and fluid rapidly escapes to the pericapillary tissue. We assessed the effects of endotoxemia and peritonitis, and the use of high and moderate volume fluid resuscitation on jejunal contractility. We hypothesized that both endotoxemia and peritonitis impair jejunum contractility and relaxation, and that this effect is aggravated in peritonitis and with high fluid administration...
December 14, 2017: Shock
https://www.readbyqxmd.com/read/29251642/l-arginine-and-arginase-products-potentiate-dexmedetomidine-induced-contractions-in-the-rat-aorta
#20
Emily S W Wong, Ricky Y K Man, Kwok F J Ng, Susan W S Leung, Paul M Vanhoutte
BACKGROUND: The α2-adrenergic sedative/anesthetic agent dexmedetomidine exerts biphasic effects on isolated arteries, causing endothelium-dependent relaxations at concentrations at or below 30 nM, followed by contractions at higher concentrations. L-arginine is a common substrate of endothelial nitric oxide synthase and arginases. This study was designed to investigate the role of L-arginine in modulating the overall vascular response to dexmedetomidine. METHODS: Isometric tension was measured in isolated aortic rings of Sprague Dawley rats...
December 15, 2017: Anesthesiology
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