|
|
|
Registros recuperados: 15 | |
|
| |
|
|
Olivoto,R.R.; Damiani,C.E.N.; Kassouf Silva,I.; Lofrano-Alves,M.S.; Oliveira,M.A.; Fogaça,R.T.H.. |
In cardiac and skeletal muscle, eugenol (μM range) blocks excitation-contraction coupling. In skeletal muscle, however, larger doses of eugenol (mM range) induce calcium release from the sarcoplasmic reticulum. The effects of eugenol are therefore dependent on its concentration. In this study, we evaluated the effects of eugenol on the contractility of isolated, quiescent atrial trabeculae from male Wistar rats (250-300 g; n=131) and measured atrial ATP content. Eugenol (1, 3, 5, 7, and 10 mM) increased resting tension in a dose-dependent manner. Ryanodine [100 µM; a specific ryanodine receptor (RyR) blocker] and procaine (30 mM; a nonspecific RyR blocker) did not block the increased resting tension induced by eugenol regardless of whether extracellular... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eugenol; Atrial trabeculae; Resting tension; Ryanodine; Rat; ATP. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014000400328 |
| |
|
|
Tararthuch,A.L.; Fernandez,R.; Malnic,G.. |
The interaction between H+ extrusion via H+-ATPase and Cl- conductance was studied in the C11 clone of MDCK cells, akin to the intercalated cells of the collecting duct. Cell pH (pHi) was measured by fluorescence microscopy using the fluorescein-derived probe BCECF-AM. Control recovery rate measured after a 20 mM NH4Cl acid pulse was 0.136 ± 0.008 pH units/min (dpHi/dt) in Na+ Ringer and 0.032 ± 0.003 in the absence of Na+ (0 Na+). With 0 Na+ plus the Cl- channel inhibitor NPPB (10 µM), recovery was reduced to 0.014 ± 0.001 dpHi/dt. 8-Br-cAMP, known to activate CFTR Cl- channels, increased dpHi/dt in 0 Na+ to 0.061 ± 0.009 and also in the presence of 46 nM concanamycin and 50 µM Schering 28080. Since it is thought that the Cl- dependence of H+-ATPase might... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cell pH; CAMP; ATP; H+-ATPase; Valinomycin; Cl-. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000500012 |
| |
|
|
Di Pietro,A.; Dayan,G.; Conseil,G.; Steinfels,E.; Krell,T.; Trompier,D.; Baubichon-Cortay,H.; Jault,J.-M.. |
Resistance to chemotherapy in cancer cells is mainly mediated by overexpression of P-glycoprotein (Pgp), a plasma membrane ATP-binding cassette (ABC) transporter which extrudes cytotoxic drugs at the expense of ATP hydrolysis. Pgp consists of two homologous halves each containing a transmembrane domain and a cytosolic nucleotide-binding domain (NBD) which contains two consensus Walker motifs, A and B, involved in ATP binding and hydrolysis. The protein also contains an S signature characteristic of ABC transporters. The molecular mechanism of Pgp-mediated drug transport is not known. Since the transporter has an extraordinarily broad substrate specificity, its cellular function has been described as a "hydrophobic vacuum cleaner". The limited knowledge... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: P-glycoprotein (Pgp); Multidrug resistance; Anticancer chemotherapy; ATP; Steroids; Flavonoids. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000800001 |
| |
|
|
de Deus,J.L.; Dagostin,A.L.A.; Varanda,W.A.. |
Testosterone synthesis within Leydig cells is a calcium-dependent process. Intracellular calcium levels are regulated by different processes including ATP-activated P2X purinergic receptors, T-type Ca2+ channels modulated by the luteinizing hormone, and intracellular calcium storages recruited by a calcium-induced calcium release mechanism. On the other hand, nitric oxide (NO) is reported to have an inhibitory role in testosterone production. Based on these observations, we investigated the interaction between the purinergic and nitrergic systems in Leydig cells of adult mice. For this purpose, we recorded ATP-evoked currents in isolated Leydig cells using the whole cell patch clamp technique after treatment with L-NAME (300 μM and 1 mM), L-arginine (10,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leydig cells; ATP; Purinergic receptor; Calcium; Nitric oxide; Whole cell patch clamp. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2018000500603 |
| |
|
| |
|
|
Persechini,P.M.; Bisaggio,R.C.; Alves-Neto,J.L.; Coutinho-Silva,R.. |
The effects of extracellular nucleosides and nucleotides on many organs and systems have been recognized for almost 50 years. The effects of extracellular ATP (ATPo), UTPo, ADPo, and other agonists are mediated by P2 purinoceptors. One of the most dramatic effects of ATPo is the permeabilization of plasma membranes to low molecular mass solutes of up to 900 Da. This effect is evident in several cells of the lymphohematopoietic system and is supposed to be mediated by P2Z, an ATP4--activated purinoceptor. Here, we review some basic information concerning P2 purinoceptors and focus our attention on P2Z-associated phenomena displayed by macrophages. Using fluorescent dye uptake, measurement of free intracellular Ca2+ concentration and electrophysiological... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: ATP; P2Z purinoceptor; Macrophage; Monocyte; T cell; Permeabilization. |
Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000100004 |
| |
|
|
Hourmant, Annick; Amara, Anis; Pouline, Patrick; Durand, Gael; Arzul, Genevieve; Quiniou, Francoise. |
The herbicide bentazon (CASRN 25057-89-0) is extensively used in agriculture in Brittany (France) to replace atrazine. Bentazon is not readily adsorbed by soil and therefore it enters adjacent freshwater ecosystems, making its way to estuarine and marine waters areas. Information regarding its effects on marine ecosystems is scarce. Phytotoxicity assessments were conducted in the laboratory on the common diatom Chaetoceros gracilis using both the active ingredient and its formulated product (Basamais). The 3 day EC50 Using cell counts were, respectively, 150 mg/L and 60 mu g/L for bentazon active ingredient and for bentazon-formulated while cellular volume was increased. Although bentazon is known as a photosystem II inhibitor, it produced an increase of... |
Tipo: Text |
Palavras-chave: Photosynthesis; Marine diatom; Growth; Chlorophylls; Chaetoceros gracilis; Carotenoids; Bentazon; ATP. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6637.pdf |
| |
|
| |
|
|
Suquet, Marc; Labbe, C.; Brizard, Raphael; Donval, Anne; Le Coz, Jean-rene; Quere, Claudie; Haffray, P.. |
Changes in sperm features during the movement phase are especially interesting to study in external fertilization species whose sperm duration movement is long because this implies a significant adaptation of moving cells to the external medium. This study describes the changes in tetraploid Pacific oyster sperm characteristics in relation to time post activation. Sperm individually collected on three tetraploid males were activated in seawater. Their features were analysed over a 24 h period and compared to a sperm pool collected on three diploid males as a reference. The percentage of motile spermatozoa, the intracellular ATP content, and the fine structure of spermatozoa were studied in relation to time post activation. Furthermore, the fertilisation... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Sperm; Tetraploid; Motility; ATP; Ultrastructure. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11756/8639.pdf |
| |
|
|
Le Moullac, Gilles; Cheize, Marie; Gastineau, Olivier; Daniel, Jean-yves; Le Coz, Jean-rene; Huvet, Arnaud; Moal, Jeanne; Pouvreau, Stephane; Van Wormhoudt, A; Samain, Jean-francois. |
The purpose of this study is to examine the response of the oyster Crassostrea gigas to sulphide at different biological scales. A first experiment was designed to measure for 20 h the clearance (CR) and oxygen consumption (OC) rates of oysters exposed at different concentrations of sulphide (0, 3, 6, 12, 20, and 40 mu M). The second experiment was carried out to evaluate the metabolic adaptations to chronic sulphide exposure for 10 days by measuring PK and PEPCK enzyme activities, succinate and alanine content, the adenylate energy charge (AEC), and the activity of the electron transport system (ETS)in whole oysters at above 20 mu M. PK and PEPCK mRNAs and enzyme activities have been measured in adductor muscle. When exposed to sulphide above 20 mu M, CR... |
Tipo: Text |
Palavras-chave: ATP; AEC; Electron transport system; Succcinate; Alanine; Phosphoenolpyruvate carboxykinase; Pyruvate kinase; Oxygen consumption; Clearance rate; Crassostrea gigas; Sulphide; Oyster. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3924.pdf |
| |
|
| |
|
|
Boulais, Myrina; Corporeau, Charlotte; Huvet, Arnaud; Bernard, Ismael; Quere, Claudie; Quillien, Virgile; Fabioux, Caroline; Suquet, Marc. |
Pacific oyster hatchery production remains highly variable, partially due to inconsistent gamete quality. However, little attention has been paid to oocyte quality in Pacific oyster compared to important vertebrate aquaculture species such as fishes. The aims of the present study were to identify criteria of oocyte and trochophore quality used as predictive tools for embryo developmental success at the D-larval stage. Twenty-six potential proxies of oocyte and trochophore quality were studied on 25 mature females, as determined using histology. Some morphological and biochemical characteristics of mature oocytes were described. Protein appeared to be the main constituent of fully mature Pacific oyster oocytes. Neutral lipids accounted for 61% of the total... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Oocyte quality; Trochophore; Lipid; Gene expression; ATP. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00239/35010/33544.pdf |
| |
|
| |
|
|
Kaizer,Rosilene Rodrigues; Loro,Vania Lúcia; Schetinger,Maria Rosa Chitolina; Morsch,Vera Maria; Tabaldi,Luciane Almeri; Rosa,Cíntia Saydelles da; Garcia,Luciano de Oliveira; Becker,Alexssandro G.; Baldisserotto,Bernardo. |
The effects of various levels of oxygen saturation and ammonia concentration on NTPDase (ecto-nucleoside triphosphate diphosphohydrolase, E.C. 3.6.1.5) and acetylcholinesterase (AChE, E.C. 3.1.1.7) activities in whole brain of teleost fish (Rhamdia quelen) were investigated. The fish were exposed to one of two different dissolved oxygen levels, including high oxygen (6.5 mg.L-1) or low oxygen (3.5 mg.L-1), and one of two different ammonia levels, including high ammonia (0.1 mg.L-1) or low ammonia (0.03 mg.L-1) levels. The four experimental groups included the following (A) control, or high dissolved oxygen plus low NH3; (B) low dissolved oxygen plus low NH3; (C) high dissolved oxygen plus high NH3; (D) low dissolved oxygen plus high NH3. We found that... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; ATP; ADP; AChE. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000400012 |
| |
Registros recuperados: 15 | |
|
|
|