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https://www.readbyqxmd.com/read/28433656/impaired-endothelium-derived-hyperpolarization-type-relaxation-in-superior-mesenteric-arteries-isolated-from-female-otsuka-long-evans-tokushima-fatty-rats
#1
Takayuki Matsumoto, Shota Kobayashi, Makoto Ando, Shun Watanabe, Maika Iguchi, Kumiko Taguchi, Tsuneo Kobayashi
Endothelium-derived hyperpolarization (EDH) is an important signaling mechanism of endothelium-dependent vasorelaxation, and little attention has been paid to the EDH-type responses in female metabolic syndrome such as that observed with type-2 diabetes. We previously reported that EDH-type relaxation was impaired in superior mesenteric arteries from male Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of type-2 diabetes, however, the response was unclear in female OLETF rat. Thus, the aim of this study was to examine if EDH-type relaxation was altered in superior mesenteric arteries isolated from female OLETF rats compared to age-matched, control female Long-Evans Tokushima Otsuka (LETO) rats at age 50-59 weeks...
April 19, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28433628/ca-2-dependent-hyperpolarization-hypothesis-for-mammalian-sleep
#2
REVIEW
Fumiya Tatsuki, Koji L Ode, Hiroki R Ueda
The detailed molecular mechanisms underlying the regulation of sleep/wake cycles in mammals are elusive. In this regulation, at least two mechanisms with fast and slow time scales are involved. In the faster time scale, a state of non-rapid-eye-movement (NREM) sleep can be microscopically characterized by the millisecond-to-second-order electrical behavior of neurons, namely slow-wave oscillations described by electrophysiology. In the slower time scale, the total duration of NREM sleep is homeostatically regulated by sleep pressure (the need for sleep), which is usually sustained for hours or even days and can be macroscopically described by electroencephalogram (EEG)...
April 19, 2017: Neuroscience Research
https://www.readbyqxmd.com/read/28432140/visually-evoked-3-5-hz-membrane-potential-oscillations-reduce-the-responsiveness-of-visual-cortex-neurons-in-awake-behaving-mice
#3
Michael C Einstein, Pierre-Olivier Polack, Duy T Tran, Peyman Golshani
Low frequency membrane potential (Vm) oscillations were once thought to only occur in sleeping and anesthetized states. Recently, low frequency Vm oscillations have been described in inactive awake animals, but it is unclear if they shape sensory processing in neurons and whether they occur during active awake behavioral states. To answer these questions, we performed two-photon guided whole-cell Vm recordings from primary visual cortex layer 2/3 excitatory and inhibitory neurons in awake mice during passive visual stimulation and performance of visual and auditory discrimination tasks...
April 21, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28431968/cannabinoid-cb1-and-cb2-receptors-differentially-modulate-l-and-t-type-ca-2-channels-in-rat-retinal-ganglion-cells
#4
Wen-Jing Qian, Ning Yin, Feng Gao, Yanying Miao, Qian Li, Fang Li, Xing-Huai Sun, Xiong-Li Yang, Zhongfeng Wang
Endocannabinoid signaling system is involved in regulating multiple neuronal functions in the central nervous system by activating G-protein coupled cannabinoid CB1 and CB2 receptors (CB1Rs and CB2Rs). Growing evidence has shown that CB1Rs and CB2Rs are extensively expressed in retinal ganglion cells (RGCs). Here, modulation of L- and T-types Ca(2+) channels by activating CB1Rs and CB2Rs in RGCs was investigated. Triple immunofluorescent staining showed that L-type subunit CaV1.2 was co-localized with T-type subunits (CaV3...
April 18, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/28428744/mutational-analysis-at-intersubunit-interfaces-of-an-anionic-glutamate-receptor-reveals-a-key-interaction-important-for-channel-gating-by-ivermectin
#5
Nurit Degani-Katzav, Revital Gortler, Marina Weissman, Yoav Paas
The broad-spectrum anthelmintic drug ivermectin (IVM) activates and stabilizes an open-channel conformation of invertebrate chloride-selective glutamate receptors (GluClRs), thereby causing a continuous inflow of chloride ions and sustained membrane hyperpolarization. These effects suppress nervous impulses and vital physiological processes in parasitic nematodes. The GluClRs are pentamers. Homopentameric receptors assembled from the Caenorhabditis elegans (C. elegans) GluClα (GLC-1) subunit can inherently respond to IVM but not to glutamate (the neurotransmitter)...
2017: Frontiers in Molecular Neuroscience
https://www.readbyqxmd.com/read/28428632/cyclophosphamide-induced-hcn1-channel-upregulation-in-interstitial-cajal-like-cells-leads-to-bladder-hyperactivity-in-mice
#6
Qian Liu, Zhou Long, Xingyou Dong, Teng Zhang, Jiang Zhao, Bishao Sun, Jingzhen Zhu, Jia Li, Qingqing Wang, Zhenxing Yang, Xiaoyan Hu, Longkun Li
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are confirmed to be expressed in bladder interstitial Cajal-like cells (ICC-LCs), but little is known about their possible role in cystitis-associated bladder dysfunction. The present study aimed to determine the functional role of HCN channels in regulating bladder function under inflammatory conditions. Sixty female wild-type C57BL/6J mice and sixty female HCN1-knockout mice were randomly assigned to experimental and control groups, respectively...
April 21, 2017: Experimental & Molecular Medicine
https://www.readbyqxmd.com/read/28428273/assessing-prostate-cancer-aggressiveness-with-hyperpolarized-dual-agent-3d-dynamic-imaging-of-metabolism-and-perfusion
#7
Hsin-Yu Chen, Peder E Z Larson, Robert A Bok, Cornelius von Morze, Renuka Sriram, Romelyn Delos Santos, Justin Delos Santos, Jeremy W Gordon, Naeim Bahrami, Marcus Ferrone, John Kurhanewicz, Daniel B Vigneron
New magnetic resonance (MR) molecular imaging techniques offer the potential for non-invasive, simultaneous quantification of metabolic and perfusion parameters in tumors. This study applied a 3D dynamic dual-agent hyperpolarized (13)C magnetic resonance spectroscopic imaging (MRSI) approach with (13)C-pyruvate and (13)C-urea to investigate differences in perfusion and metabolism between low and high grade tumors in the TRAMP transgenic mouse model of prostate cancer. Dynamic MR data were corrected for T1 relaxation and RF excitation and modeled to provide quantitative measures of pyruvate to lactate flux (kPL) and urea perfusion (urea AUC) that correlated with TRAMP tumor histologic grade...
April 20, 2017: Cancer Research
https://www.readbyqxmd.com/read/28428070/no-production-and-potassium-channels-activation-induced-by-crotalus-durissus-cascavella-underlie-mesenteric-artery-relaxation
#8
S S Santos, R L C Jesus, L O Simões, W P Vasconcelos, I A Medeiros, R C Veras, L L Casais-E-Silva, D F Silva
Animal toxins are natural resources for pharmacological studies. The venom of Crotalus durissus cascavella (C.d. cascavella) may be a source in the bio-prospecting of new anti-hypertensive agents. The aim of this study was to investigate vascular effects of the venom of C.d. cascavella in normotensive rats. Studies were performed using isolated mesenteric artery segments and aortic endothelial cells. The cumulative administration of the venom of C.d. cascavella (0.001-30 μg/mL) on phenylephrine (Phe; 10 μM) pre-contracted rings induced a concentration-dependent vasorelaxation in the presence of vascular endothelium (Emax = 47...
April 18, 2017: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/28426671/effect-of-mitochondrially-targeted-carboxy-proxyl-nitroxide-on-akt-mediated-survival-in-daudi-cells-significance-of-a-dual-mode-of-action
#9
Gokul Variar, Tarun Pant, Apoorva Singh, Abinaya Ravichandran, Sushant Swami, Balaraman Kalyanaraman, Anuradha Dhanasekaran
Vicious cycles of mutations and reactive oxygen species (ROS) generation contribute to cancer progression. The use of antioxidants to inhibit ROS generation promotes cytostasis by affecting the mutation cycle and ROS-dependent survival signaling. However, cancer cells select mutations to elevate ROS albeit maintaining mitochondrial hyperpolarization (Δψm), even under hypoxia. From this perspective, the use of drugs that disrupt both ROS generation and Δψm is a viable anticancer strategy. Hence, we studied the effects of mitochondrially targeted carboxy proxyl nitroxide (Mito-CP) and a control ten carbon TPP moiety (Dec-TPP+) in the human Burkitt lymphoma cell line (Daudi) and normal peripheral blood mononuclear cells under hypoxia and normoxia...
2017: PloS One
https://www.readbyqxmd.com/read/28425495/the-biglen-gpr171-peptide-receptor-system-within-the-basolateral-amygdala-regulates-anxiety-like-behavior-and-contextual-fear-conditioning
#10
Erin N Bobeck, Ivone Gomes, Darlene Pena, Kirstie A Cummings, Roger L Clem, Mihaly Mezei, Lakshmi A Devi
Studies show that neuropeptide-receptor systems in the basolateral amygdala (BLA) play an important role in the pathology of anxiety and other mood disorders. Since GPR171, a recently deorphanized receptor for the abundant neuropeptide BigLEN, is expressed in the BLA, we investigated its role in fear and anxiety-like behaviors. To carry out these studies we identified small molecule ligands using a homology model of GPR171 to virtually screen a library of compounds. One of the hits, MS0021570_1, was identified as a GPR171 antagonist based on its ability to block (i) BigLEN-mediated activation of GPR171 in heterologous cells, (ii) BigLEN-mediated hyperpolarization of BLA pyramidal neurons, and (iii) feeding induced by DREADD-mediated activation of BigLEN containing AgRP neurons in the arcuate nucleus...
April 20, 2017: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/28425467/hyperpolarized-13-c-spectroscopic-evaluation-of-oxidative-stress-in-a-rodent-model-of-steatohepatitis
#11
David M Wilson, Valentina Di Gialleonardo, Zhen J Wang, Valerie Carroll, Cornelius Von Morze, Andrew Taylor, Victor Sai, Mark VanCriekinge, Robert Bok, Michael A Ohliger, Kayvan R Keshari
Nonalcoholic fatty liver disease (NAFLD) has become highly prevalent, now considered the most common liver disease in the western world. Approximately one-third of patients with NASH develop non-alchoholic steatohepatitis (NASH), histologically defined by lobular and portal inflammation, and accompanied by marked oxidative stress. Patients with NASH are at increased risk for cirrhosis and hepatocellular carcinoma, and diagnosis currently requires invasive biopsy. In animal models of NASH, particularly the methionine-choline deficient (MCD) model, profound changes are seen in redox enzymes and key intracellular antioxidants...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28423317/loss-of-nav%C3%AE-4-mediated-regulation-of-sodium-currents-in-adult-purkinje-neurons-disrupts-firing-and-impairs-motor-coordination-and-balance
#12
Joseph L Ransdell, Edward Dranoff, Brandon Lau, Wan-Lin Lo, David L Donermeyer, Paul M Allen, Jeanne M Nerbonne
The resurgent component of voltage-gated Na(+) (Nav) currents, INaR, has been suggested to provide the depolarizing drive for high-frequency firing and to be generated by voltage-dependent Nav channel block (at depolarized potentials) and unblock (at hyperpolarized potentials) by the accessory Navβ4 subunit. To test these hypotheses, we examined the effects of the targeted deletion of Scn4b (Navβ4) on INaR and on repetitive firing in cerebellar Purkinje neurons. We show here that Scn4b(-/-) animals have deficits in motor coordination and balance and that firing rates in Scn4b(-/-) Purkinje neurons are markedly attenuated...
April 18, 2017: Cell Reports
https://www.readbyqxmd.com/read/28422818/inhibition-of-metabotropic-glutamate-receptor-subtype-1-alters-the-excitability-of-the-commissural-pyramidal-neuron-in-the-rat-anterior-cingulate-cortex-after-chronic-constriction-injury-to-the-sciatic-nerve
#13
Shi-Hao Gao, Lin-Lin Shen, Hui-Zhong Wen, Yan-Dong Zhao, Huai-Zhen Ruan
BACKGROUND: Inhibition of the metabotropic glutamate receptor subtype 1 in the anterior cingulate cortex has an analgesic effect during sustained nociceptive hypersensitivity. However, the specific changes in different subtypes of anterior cingulate cortex layer 5 pyramidal neurons, as well as the distinct effect of metabotropic glutamate receptor subtype 1 inhibition on different neuronal subtypes, have not been well studied. METHODS: Retrograde labeling combined with immunofluorescence, whole cell clamp recording, and behavioral tests combined with RNA interference were performed in a rat model of chronic constriction injury to the sciatic nerve...
April 19, 2017: Anesthesiology
https://www.readbyqxmd.com/read/28419644/diffusion-weighted-imaging-of-hyperpolarized-13-c-urea-in-mouse-liver
#14
Irene Marco-Rius, Jeremy W Gordon, Aras N Mattis, Robert Bok, Romelyn Delos Santos, Subramanian Sukumar, Peder E Z Larson, Daniel B Vigneron, Michael A Ohliger
PURPOSE: To compare the apparent diffusion coefficient (ADC) of hyperpolarized (HP) [(13) C,(15) N]urea to the ADC of endogenous water in healthy and fibrotic mouse liver. MATERIALS AND METHODS: ADC measurements for water and [(13) C]urea were made in agarose phantoms at 14.1T. Next, the ADC of water and injected HP [(13) C,(15) N]urea were measured in eight CD1 mouse livers before and after induction of liver fibrosis using CCl4 . Liver fibrosis was quantified pathologically using the modified Brunt fibrosis score and compared to the measured ADC of water and urea...
April 17, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28419216/lav-bpifb4-isoform-modulates-enos-signaling-through-ca2-pkc-alpha-dependent-mechanism
#15
Chiara Carmela Spinelli, Albino Carrizzo, Anna Ferrario, Francesco Villa, Antonio Damato, Mariateresa Ambrosio, Michele Madonna, Giacomo Frati, Sergio Fucile, Miriam Sciaccalunga, Mario Capunzo, Gaetano Calì, Luciano Milanesi, Anna Maciag, Annibale Alessandro Puca, Carmine Vecchione
Aims: Aging is associated with impairment of endothelial nitric oxide synthase (eNOS) and progressive reduction in endothelial function. A genetic study on long-living individuals - who are characterized by delays in aging and in the onset of cardiovascular disease - previously revealed I229V ( rs2070325 ) in BPIFB4 as a longevity-associated variant (LAV); the LAV protein enhanced endothelial NO production and vasorelaxation through a PERK/14-3-3/HSP90 signal. Here, we further characterize the molecular mechanisms underlying LAV-BPIFB4-dependent enhancement of vascular function...
April 13, 2017: Cardiovascular Research
https://www.readbyqxmd.com/read/28417339/expression-and-function-of-the-small-conductance-ca-2-activated-k-channel-is-decreased-in-urinary-bladder-smooth-muscle-cells-from-female-guinea-pig-with-partial-bladder-outlet-obstruction
#16
Ning Li, Honglin Ding, Xiaoning He, Zizheng Li, Yili Liu
PURPOSE: Overactive bladder (OAB), usually accompanied by partial bladder outlet obstruction (PBOO), is associated with detrusor overactivity (DO) which is related to the increased urinary bladder smooth muscle (UBSM) cells excitability. Small-conductance Ca(2+)-activated K(+) (SK) channels play a constitutive regulatory role of UBSM excitability and contractility. PBOO is associated with the decreased SK channels mRNA expression and the attenuated regulative effect of SK channels on UBSM contractility...
April 17, 2017: International Urology and Nephrology
https://www.readbyqxmd.com/read/28413833/beneficial-effects-of-a-pyrroloquinolinequinone-containing-dietary-formulation-on-motor-deficiency-cognitive-decline-and-mitochondrial-dysfunction-in-a-mouse-model-of-alzheimer-s-disease
#17
Darrell Sawmiller, Song Li, Takashi Mori, Ahsan Habib, David Rongo, Vedad Delic, Patrick C Bradshaw, R Douglas Shytle, Cyndy Sanberg, Paula Bickford, Jun Tan
Alzheimer's disease (AD), a progressive neurodegenerative disorder, is linked to oxidative stress, altered amyloid precursor protein (APP) proteolysis, tau hyperphosphorylation and the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles (NFT). A growing body of evidence suggests that mitochondrial dysfunction can be a key promoter of all of these pathologies and predicts that restoration of mitochondrial function might be a potential therapeutic strategy for AD. Therefore, in the present study, we tested the beneficial effect of a nutraceutical formulation Nutrastem II (Nutra II), containing NT020 (a mitochondrial restorative and antioxidant proprietary formulation) and pyrroloquinolinequinone (PQQ, a stimulator of mitochondria biogenesis) in 5XFAD transgenic mice...
April 2017: Heliyon
https://www.readbyqxmd.com/read/28411229/a-comprehensive-analysis-of-myocardial-substrate-preference-emphasizes-the-need-for-a-synchronized-fluxomic-metabolomic-research-design
#18
Mukundan Ragavan, Alexander Kirpich, Xiaorong Fu, Shawn C Burgess, Lauren M McIntyre, Matthew E Merritt
The heart oxidizes fatty acids, carbohydrates and ketone bodies inside the citric acid cycle (CAC) to generate the reducing equivalents needed for ATP production. Competition between these substrates makes it difficult to estimate the extent of pyruvate oxidation. Previously, hyperpolarized pyruvate detected propionate mediated activation of carbohydrate oxidation, even in the presence of acetate. In this report, the optimal concentration of propionate for activation of glucose oxidation is measured in mouse hearts perfused in Langendorff mode...
April 14, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28411183/membrane-permeation-of-arginine-rich-cell-penetrating-peptides-independent-of-transmembrane-potential-as-a-function-of-lipid-composition-and-membrane-fluidity
#19
Rike Wallbrecher, Tobias Ackels, R Alis Olea, Marco J Klein, Lucie Caillon, Jürgen Schiller, Petra H Bovée-Geurts, Toin H van Kuppevelt, Anne S Ulrich, Marc Spehr, Merel J W Adjobo-Hermans, Roland Brock
Cell-penetrating peptides (CPPs) are prominent delivery vehicles to confer cellular entry of (bio-) macromolecules. Internalization efficiency and uptake mechanism depend, next to the type of CPP and cargo, also on cell type. Direct penetration of the plasma membrane is the preferred route of entry as this circumvents endolysosomal sequestration. However, the molecular parameters underlying this import mechanism are still poorly defined. Here, we make use of the frequently used HeLa and HEK cell lines to address the role of lipid composition and membrane potential...
April 11, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28411158/intrinsic-membrane-properties-and-cholinergic-modulation-of-mouse-basal-forebrain-glutamatergic-neurons-in-vitro
#20
Chun Yang, James T McKenna, Ritchie E Brown
The basal forebrain (BF) controls sleep-wake cycles, attention and reward processing. Compared to cholinergic and GABAergic neurons, BF glutamatergic neurons are less well understood, due to difficulties in identification. Here, we use vesicular glutamate transporter 2 (vGluT2)-tdTomato mice, expressing a red fluorescent protein (tdTomato) in the major group of BF glutamatergic neurons (vGluT2+) to characterize their intrinsic electrical properties and cholinergic modulation. Whole-cell, patch-clamp recordings were made from vGluT2+ neurons in coronal BF slices...
April 12, 2017: Neuroscience
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