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https://www.readbyqxmd.com/read/29242169/c60-fullerenes-disrupt-cellular-signalling-leading-to-trpc4-and-trpc6-channels-opening-by-the-activation-of-muscarinic-receptors-and-g-proteins-in-small-intestinal-smooth-muscles
#1
Dariia O Dryn, Mariia I Melnyk, Lina T Al Kury, Yuriy I Prylutskyy, Uwe Ritter, Alexander V Zholos
The effect of water-soluble pristine C60 fullerene nanoparticles (C60NPs) on receptor-operated cation channels formed by TRPC4/C6 proteins in ileal smooth muscle cells was investigated for the first time. Activation of these channels subsequent to acetylcholine binding to the expressed in these cells M2 and M3 muscarinic receptors represents the key event in the parasympathetic control of gastrointestinal smooth muscle motility and cholinergic excitation-contraction coupling. Experiments were performed on single collagenase-dispersed mouse ileal myocytes using patch-clamp techniques with symmetrical 125mM Cs+ solutions and [Ca2+]i 'clamped' at 100nM in order to isolate the muscarinic cation current (mICAT)...
December 11, 2017: Cellular Signalling
https://www.readbyqxmd.com/read/29241653/synaptic-adaptations-to-chronic-ethanol-intake-in-male-rhesus-monkey-dorsal-striatum-depend-on-age-of-drinking-onset
#2
Verginia C Cuzon Carlson, Kathleen A Grant, David M Lovinger
One in 12 adults suffer with alcohol use disorder (AUD). Studies suggest the younger the age in which alcohol consumption begins the higher the probability of being diagnosed with AUD. Binge/excessive alcohol drinking involves a transition from flexible to inflexible behavior likely involving the dorsal striatum (caudate and putamen nuclei). A major focus of this study was to examine the effect of age of drinking onset on subsequent chronic, voluntary ethanol intake and dorsal striatal circuitry. Data from rhesus monkeys (n = 45) that started drinking as adolescents, young adults or mature adults confirms an age-related risk for heavy drinking...
December 12, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/29239964/superior-efficacy-of-lipid-emulsion-infusion-over-serum-alkalinization-in-reversing-amitriptyline-induced-cardiotoxicity-in-guinea-pig
#3
Shogo Tsujikawa, Tadashi Matsuura, Kotaro Hori, Takashi Mori, Miyuki Kuno, Kiyonobu Nishikawa
BACKGROUND: Tricyclic antidepressants (TCAs) are a major cause of fatal drug poisoning due to their cardiotoxicity. Alkalinization by sodium bicarbonate (NaHCO3) administration, the first-line therapy for TCA-induced cardiotoxicity, can occasionally yield insufficient efficacy in severe cases. Because most TCAs are highly lipophilic, lipid emulsion may be more effective than alkalinization. However, it remains to be determined whether lipid emulsion is more beneficial than alkalinization in reversing amitriptyline-induced cardiotoxicity...
December 11, 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/29237755/differential-contribution-of-ca2-sources-to-day-and-night-bk-current-activation-in-the-circadian-clock
#4
Joshua P Whitt, Beth A McNally, Andrea L Meredith
Large conductance K+ (BK) channels are expressed widely in neurons, where their activation is regulated by membrane depolarization and intracellular Ca2+ (Ca2+i). To enable this regulation, BK channels functionally couple to both voltage-gated Ca2+ channels (VGCCs) and channels mediating Ca2+ release from intracellular stores. However, the relationship between BK channels and their specific Ca2+ source for particular patterns of excitability is not well understood. In neurons within the suprachiasmatic nucleus (SCN)-the brain's circadian clock-BK current, VGCC current, and Ca2+i are diurnally regulated, but paradoxically, BK current is greatest at night when VGCC current and Ca2+i are reduced...
December 13, 2017: Journal of General Physiology
https://www.readbyqxmd.com/read/29237731/naked-mole-rat-acid-sensing-ion-channel-3-forms-nonfunctional-homomers-but-functional-heteromers
#5
Laura-Nadine Schuhmacher, Gerard Callejo, Shyam Srivats, Ewan St John Smith
Acid-sensing ion channels (ASICs) form both homotrimeric and heterotrimeric ion channels that are activated by extracellular protons and are involved in a wide range of physiological and pathophysiological processes, including pain and anxiety. ASIC proteins can form both homotrimeric and heterotrimeric ion channels. The ASIC3 subunit has been shown to be of particular importance in the peripheral nervous system with pharmacological and genetic manipulations demonstrating a role in pain. Naked mole-rats, despite having functional ASICs, are insensitive to acid as a noxious stimulus and show diminished avoidance of acidic fumes, ammonia and carbon dioxide...
December 13, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/29236481/exploring-the-nanotoxicology-of-mos2-a-study-on-the-interaction-of-mos2-nanoflake-and-k-channels
#6
Zonglin Gu, Leigh D Plant, Xuanyu Meng, Jose Manuel Perez-Aguilar, Zegao Wang, Mingdong Dong, Diomedes E Logothetis, Ruhong Zhou
Molybdenum disulfide (MoS2) nanomaterial has recently found various applications in the biomedical field mainly due to its outstanding physicochemical properties. However, little is known about its interactions with biological systems at the atomic level, which intimately relates to the biocompatibility of the material. To provide insights into the effects of MoS2 in biological entities, we investigated the interactions of MoS2 with proteins from a functionally important membrane family, the ubiquitous potassium (K+) channels...
December 13, 2017: ACS Nano
https://www.readbyqxmd.com/read/29233211/toxicity-of-marine-pollutants-on-the-ascidian-oocyte-physiology-an-electrophysiological-approach
#7
Alessandra Gallo
In marine animals with external fertilization, gametes are released into seawater where fertilization and embryo development occur. Consequently, pollutants introduced into the marine environment by human activities may affect gametes and embryos. These xenobiotics can alter cell physiology with consequent reduction of fertilization success. Here the adverse effects on the reproductive processes of the marine invertebrate Ciona intestinalis (ascidian) of different xenobiotics: lead, zinc, an organic tin compound and a phenylurea herbicide were evaluated...
December 13, 2017: Zygote: the Biology of Gametes and Early Embryos
https://www.readbyqxmd.com/read/29229531/eriodictyol-stimulates-insulin-secretion-through-camp-pka-signaling-pathway-in-mice-islets
#8
Abdul Hameed, Rahman M Hafizur, Nusrat Hussain, Sayed Ali Raza, Mujeeb-Ur-Rehman, Sajda Ashraf, Zaheer Ul-Haq, Faisal Khan, Ghulam Abbas, M Iqbal Choudhary
Eriodictyol, a flavonoid isolated from Lyonia ovalifolia, was found to be the most potent insulin secretagogue in our preliminary studies. Here, we explored mechanism(s) of insulin secretory activity of eriodictyol in vitro and in vivo. Mice islets and MIN6 cells were incubated in basal and stimulatory glucose containing eriodictyol with or without agonist/antagonist. Secreted insulin and cAMP contents were measured using ELISA kits. K+- and Ca2+-channels currents were recorded with patch-clamp technique. Oral glucose tolerance test and plasma insulin was evaluated in non-diabetic and diabetic rats...
December 8, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29225568/age-dependent-subunit-specific-action-of-hydrogen-sulfide-on-glun1-2a-and-glun1-2b-nmda-receptors
#9
Aleksey V Yakovlev, Evgeniya D Kurmasheva, Yevheniia Ishchenko, Rashid Giniatullin, Guzel F Sitdikova
Hydrogen sulfide (H2S) is an endogenously produced neuroactive gas implicated in many key processes in the peripheral and central nervous system. Whereas the neuroprotective role of H2S has been shown in adult brain, the action of this messenger in newborns remains unclear. One of the known targets of H2S in the nervous system is the N-methyl-D-aspartate (NMDA) glutamate receptor which can be composed of different subunits with distinct functional properties. In the present study, using patch clamp technique, we compared the effects of the H2S donor sodium hydrosulfide (NaHS, 100 μM) on hippocampal NMDA receptor mediated currents in rats of the first and third postnatal weeks...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/29225214/noradrenergic-effects-in-rat-sacral-autonomic-nucleus-using-in-vitro-slice-patch-clamp-recordings
#10
Masahiro Kawatani, Nozomi Akimoto, Akihiro Yamada, Hidemasa Furue, Masahito Kawatani
Noradrenergic modulation has been frequently discussed in the context of neural activities that are related to pelvic organs. The sacral preganglionic nucleus (SPN) is a spinal nucleus containing parasympathetic preganglionic neurons that send fibers to pelvic nerves. In spite of the abundant presence of noradrenergic fibers around the SPN, the effects of noradrenaline (NA) remain obscure. To explore this issue, NA (50 μM) was applied to parasympathetic preganglionic neurons in the SPN during whole-cell patch clamp recording...
2017: Biomedical Research
https://www.readbyqxmd.com/read/29225191/the-comprehensive-electrophysiological-study-of-curcuminoids-on-delayed-rectifier-k-currents-in-insulin-secreting-cells
#11
Ping-Chung Kuo, Chia-Jung Yang, Yu-Chi Lee, Pei-Chun Chen, Yen-Chin Liu, Sheng-Nan Wu
Curcumin (CUR) has been demonstrated to induce insulin release from pancreatic β-cells; however, how curcuminoids (including demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC)) exert any possible effects on membrane ion currents inherently in insulin-secreting cells remains largely unclear. The effects of CUR and other structurally similar curcuminoids on ion currents in rat insulin-secreting (INS-1) insulinoma cells were therefore investigated in this study. The effects of these compounds on ionic currents and membrane potential were studied by patch-clamp technique...
December 7, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29225093/effects-of-the-antidepressant-mirtazapine-and-zinc-on-nicotinic-acetylcholine-receptors
#12
Andy Hernández-Abrego, Elizabeth Vázquez-Gómez, Jesús García-Colunga
Nicotinic acetylcholine receptors (nAChRs) and zinc are associated with regulation of mood and related disorders. In addition, several antidepressants inhibit muscle and neuronal nAChRs and zinc potentiates inhibitory actions of them. Moreover, mirtazapine (a noradrenergic, serotonergic and histaminergic antidepressant) inhibits muscarinic AChRs and its effects on nAChRs are unknown. Therefore, we studied the modulation of muscle α1β1γd nAChRs expressed in oocytes and native α7-containing nAChRs in hippocampal interneurons by mirtazapine and/or zinc, using voltage-clamp techniques...
December 7, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/29222635/cardiovascular-response-of-rat-aorta-to-di-2-ethylhexyl-phthalate-dehp-exposure
#13
Melissa Mariana, Joana Feiteiro, Elisa Cairrao
Phthalates are one of the main constituents of plastic, reaching up to 40% of the total plastic weight, and their main function is to impart flexibility/elasticity to polymers that would otherwise be rigid. Phthalates are known as endocrine disruptors, since they can interfere with hormone homeostasis. Regarding the cardiovascular system, it was already shown the effects of di-(2-ethylhexyl) phthalate (DEHP) exposure with significant changes in several calcium-handling proteins and an increase in the blood pressure of mice offspring, suggesting that DEHP leads to vasocontraction...
December 8, 2017: Cardiovascular Toxicology
https://www.readbyqxmd.com/read/29215466/sensitivity-of-takifugu-trpa1-to-thermal-stimulations-analyzed-in-oocytes-expression-system
#14
Mai Oda, Yoshihiro Kubo, Osamu Saitoh
Transient receptor potential ankyrin 1 (TRPA1s) from insects and several tetrapod vertebrates except rodents have been reported to be activated by high temperature with a relatively clear threshold. Our previous report, however, indicated that oocytes expressing zebrafish TRPA1b showed cold and heat-induced responses. Further, we also observed that zebrafish TRPA1b was gradually heat activated without a clear threshold. To study the possibility that these unique properties of thermal sensing of zebrafish TRPA1b are common to TRPA1s from other fish, we focused on the thermal response of pufferfish transient receptor potential ankyrin 1 (pfTRPA1) in the present study...
December 5, 2017: Neuroreport
https://www.readbyqxmd.com/read/29214635/kv4-2-channel-activity-controls-intrinsic-firing-dynamics-of-arcuate-kisspeptin-neurons
#15
Philipe R F Mendonça, Victoria Kyle, Shel-Hwa Yeo, William H Colledge, Hugh P C Robinson
Kisspeptin neurons in the hypothalamus are critically involved in reproductive function, via their effect on GnRH neuron activity and consequent gonadotropin release. Kisspeptin neurons show an intrinsic irregularity of firing, but the mechanism of this remains unclear. To address this, we carried out targeted whole-cell patch-clamp recordings of kisspeptin neurons in the arcuate nucleus (Kiss1Arc ), in brain slices isolated from adult male Kiss-Cre:tdTomato mice. Cells fired irregularly in response to constant current stimuli, with a wide range of spike time variability, and prominent subthreshold voltage fluctuations...
December 6, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/29213241/interaction-of-purinergic-p2x4-and-p2x7-receptor-subunits
#16
Markus Schneider, Kirsten Prudic, Anja Pippel, Manuela Klapperstück, Ursula Braam, Christa E Müller, Günther Schmalzing, Fritz Markwardt
P2X4 and P2X7 are members of the P2X receptor family, comprising seven isoforms (P2X1-P2X7) that form homo- and heterotrimeric non-specific cation channels gated by extracellular ATP. P2X4 and P2X7 are widely coexpressed, particularly in secretory epithelial cells and immune and inflammatory cells, and regulate inflammation and nociception. Although functional heteromerization has been established for P2X2 and P2X3 subunits expressed in sensory neurons, there are contradictory reports regarding a functional interaction between P2X4 and P2X7 subunits...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/29212769/functional-and-structural-characterization-of-a-novel-malignant-hyperthermia-susceptible-variant-of-dhpr-%C3%AE-1a-subunit-cacnb1
#17
Claudio F Perez, Jose M Eltit, Jose R Lopez, Dóra Bodnár, Angela F Dulhunty, Shouvik Aditya, Marco G Casarotto
Malignant Hyperthermia (MH) susceptibility has been recently linked to a novel variant of β1a subunit of the dihydropyridine receptor (DHPR), a channel essential for Ca2+ regulation in skeletal muscle. Here we evaluate the effect of the mutant variant V156A on the structure/function of DHPR β1a subunit and assess its role on Ca2+ metabolism of cultured myotubes. Using differential scanning fluorimetry we show that mutation V156A causes a significant reduction in thermal stability of the Src homology 3 (SH3)/Guanylate Kinase (GK) core domain of β1a subunit...
December 6, 2017: American Journal of Physiology. Cell Physiology
https://www.readbyqxmd.com/read/29211992/fluctuation-analysis-in-nonstationary-conditions-single-ca2-channel-current-in-pyramidal-neurons
#18
Christian Scheppach, Hugh P C Robinson
Fluctuation analysis is a method that allows measurement of the single-channel current of ion channels even when it is too small to be resolved directly with the patch-clamp technique. This is the case for voltage-gated calcium channels. They are present in all mammalian central neurons, controlling presynaptic release of transmitter, postsynaptic signaling, and synaptic integration. The amplitudes of their single-channel currents in a physiological concentration of extracellular calcium, however, are small and not well determined...
December 5, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/29211342/functional-bkca-channel-in-human-resident-cardiac-stem-cells-expressing-w8b2
#19
Oualid Ayad, Christophe Magaud, Stéphane Sebille, Jocelyn Bescond, Chloé Mimbimi, Christian Cognard, Jean-Francois Faivre, Patrick Bois, Aurelien Chatelier
Recently, a new population of resident cardiac stem cells positive for W8B2 marker has been identified. These cardiac stem cells (CSCs) are considered as an ideal cellular source to repair myocardial damage after infarction. However, the electrophysiological profile of these cells has not been characterized yet. We first establish the conditions of isolation and expansion of W8B2+ CSCs from human heart biopsies using magnetic sorting system followed by flow cytometry cell sorting. These cells display a spindle-shaped morphology, are highly proliferative and possess self-renewal capacity demonstrated by their ability to form colonies...
December 6, 2017: FEBS Journal
https://www.readbyqxmd.com/read/29210458/distribution-of-cardiac-sodium-channels-in-clusters-potentiates-ephaptic-interactions-in-the-intercalated-disc
#20
Echrak Hichri, Hugues Abriel, Jan P Kucera
It has been proposed that ephaptic interactions in intercalated discs, mediated by extracellular potentials, contribute to cardiac impulse propagation when gap junctional coupling is reduced. However, experiments demonstrating ephaptic effects on the cardiac Na+ current (INa ) are scarce. Furthermore, Na+ channels form clusters around gap junction plaques, but the electrophysiological significance of these clusters has never been investigated. In patch clamp experiments with HEK cells stably expressing human Nav 1...
December 6, 2017: Journal of Physiology
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