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Tityus serrulatus venom and its toxins Ts1 and Ts5 increase cytosolic Ca^(2+)concentration in isolated vascular smooth muscle cells

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Journal of Biophysical Chemistry 2012年第4期3卷 287-294页

作者： mario dos A.Neto Flavio Vasconcelos lusiane m.bendhack Eliane C.Arantes Faculty of Inga-UNINGA MaringaBrazil Laboratory of Pharmacology Department of Physics and ChemistryFaculty of Pharmaceutical Sciences of Ribeirao PretoUniversity of Sao PauloRibeirao PretoBrazil Laboratory of Animal Toxins Department of Physics and ChemistryFaculty of Pharmaceutical Sciences of Ribeirao PretoUniversity of Sao PauloRibeirao PretoBrazil Laboratory of Toxicology Faculty of PharmacyInstitute of Health SciencesFederal University of ParaBelemBrazil

Voltage-gated Na+ channel (Nav channel) scorpion toxins are classified as α- and β-neurotoxins. Ts5 (α-neurotoxin) and Ts1 (β-neurotoxin) from Tityus serrulatus venom (TsV) interact with Nav channels, increasing Na+ influx and activating voltage-dependent Ca2+ channels. This study aimed to investigate the effect of TsV, Ts1 and Ts5 on the cytosolic Ca2+ concentration ([Ca2+]C) in rat aortic smooth muscle cells. Toxins were isolated by ion exchange chromatography (Ts1) followed by RP-HPLC (Ts5). The rat aortic smooth muscle cells were isolated in Hanks buffer pH 7.4 and loaded with 5 μmol/L of Fura-2Am (45 minutes at 37℃), in order to measure [Ca2+]C by fluorescence of Fura-2/Am (ratio 340/380 nm). The fluorescence was measured in one single cell (excitation: 340 and 380 nm;emission: 510 nm). TsV (100 and 500 mg/mL) and its toxins Ts1 and Ts5 (50 and 100 mg/mL each) led to a concentration-dependent increase in [Ca2+]C. Tetrodotoxin (1 mmol/L), a Nav channel blocker, and verapamil (1 mmol/L), a voltage-operated Ca2+ channel blocker, inhibited the increase in [Ca2+]C induced by TsV (500 mg/mL). In conclusion, TsV and its toxins induce a concentration-dependent increase in [Ca2+]C that probably occurs through interaction with Nav channels, thus inducing depolarization and consequent Ca2+ influx. This assumption is based on the fact that this effect is inhibited by tetrodotoxin and verapamil, showing a direct action of TsV toxins on aorta smooth muscle cells.

关键词： Ts1 Ts5 Na^(+) Channel Ca^(2+) Channel Tityus serrulatus

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Vasodilatation induced by forskolin involves cyclic GmP production

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Journal of Biophysical Chemistry 2011年第4期2卷 373-379页

作者： mário dos Anjos Neto Claure Nain Lunardi Gerson Jhonatan Rodrigues lusiane maria bendhack 不详

Endothelium-derived relaxing factors contribute to smooth muscle relaxation. The aim of the present study was to investigate the contribution of nitric oxide (NO) produced in the endothelial cells to the vasodilatation stimulated with forskolin in rat aorta. Forskolin that directly activates adenylyl-cyclase, induced complete relaxation in phenylephrine-contracted aortas. Endothelium removal reduced the potency (pEC50) of forskolin without changes in the maximum effect (Emax). However, the inhibitor of endothelial NO-synthase (10 μm L- NG-Nitroarginine, L-NNA) reduced both Emax and pEC50 in intact endothelium aortic rings. L-NNA or L-NNA plus cyclooxygenase inhibitor indomethacin (10 μm) reduced both Emax and pEC50 of forskolin. Forskolin increased both the cytosolic Ca+2 concentration and the cytosolic NO concentration ([NO]c) in the endothelial cells. The PKA inhibitor KT5720 reduced the NO production activated by forskolin in the endothelial cells. The enhanced [NO]c in the endothelial cells increased cyclic guanosine-monophosphate (cGmP) in smooth muscle cells, which was abolished by L-NNA. Taken together, our results indicate that vasodilatation mediated by forskolin in rat aortic rings is potentiated by NO production in endothelial cells that increases the cGmP levels in the smooth muscle cells that along with cAmP contribute to the vasodilatation.

关键词： Forskolin Cytosolic Calcium cAmP cGmP Endothelial Cells Nitric Oxide

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Role of endothelium on the abnormal Angiotensin-mediated vascular functions in epileptic rats

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Journal of Biophysical Chemistry 2012年第2期3卷 174-182页

作者： Carolina Restini Rosana Reis Claudio Costa-Neto Norberto Garcia-Cairasco José Cortes-de-Oliveira lusiane bendhack Universidade de Ribeiraão Preto—UNAERP. Curso de medicina Ribeirāo Preto Brasil Faculdade de Ciências Farmacêuticas de Ribeiro Preto-USP Ribeiro Preto Brasil Faculdade de medicina de Ribeirão Preto-USP Ribeir&atildeo Preto Brasil Faculdade de medicina de Ribeiro Preto-USP Ribeiro Preto Brasil

Epidemiological studies have found that the risk for cardiovascular disease is increased in patients with epilepsy. The Renin Angiontensin System (RAS), an important player in vascular tone control, is also involved in many neurological disorders, including seizures and epilepsy. Although it has been reported that Angiotensin II (Ang II) release and Angiotensin receptors expression are altered in many cerebral areas in patients/animal models with neurological disorders, there are no data on the vascular function. We evaluated Ang I and Ang II-mediated vascular responses and to correlate their contractile responses to the pres- ence of endothelium and the protein levels of components of the RAS (AT1, AT2, mas and ACE) in aorta isolated from genetically epileptic rats (WAR strain). The major finding was that the vascular contractile response induced by Ang I and Ang II is endothelium-dependent. Ang II induced contractions in aortas from Wistar rats either with intact endothelium (E+) (1.16 ± 0.04 g, n = 6) and endothelium-denuded (E-) (1.24 ± 0.04 g, n = 6). maximum contractile response (mE) induced by Ang I was lower in Wistar E+ (0.45 ± 0.03 g, n = 6) compared with Wistar E- (1.13 ± 0.08 g, n = 6). Ang I and Ang II failed to induce contraction in WAR E+, whereas the mE induced by Ang I in WAR E- was lower (0.52 ± 0.04 g, n = 11) than in the Wistar. mE induced by Ang II in aortas from WAR was also lower (0.40 ± 0.03 g, n = 11) compared with Wistar. AT1 receptor expression in both E+ WAR and Wistar was lower than in both E- WAR and Wistar. AT2 and mas receptor expression was higher in Wistar E- and E+ as compared to WAR E- and E+. ACE expression was higher in both E+ WAR and Wistar, but it was lower in both E- WAR and Wistar. Endothelium impairs the contractile response induced by Angiotensin in WAR, suggesting that endothelial relaxing factors play important role on the aorta contraction.

关键词： Endothelium Aorta myogenic Tone Angiotensin Angiotensin II Receptor Epilepsy

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Vasodilatation induced by forskolin involves cyclic GmP production

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Journal of Biophysical Chemistry（生物物理化学） 2011年第4期

作者： mário dos Anjos Neto Claure Nain Lunardi Gerson Jhonatan Rodrigues lusiane maria bendhack

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Role of endothelium on the abnormal Angiotensin-mediated vascular functions in epileptic rats

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Journal of Biophysical Chemistry（生物物理化学） 2012年第2期

作者： Carolina Restini Rosana Reis Claudio Costa-Neto Norberto Garcia-Cairasco José Cortes-de-Oliveira lusiane bendhack

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Where Are the Bromeliads? A Study on Different Trails in the Ecological Reserve of Guapiaçu, RJ

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Agricultural Sciences 2023年第2期14卷 196-201页

作者： Johnatan Jair de Paula marchiori Vinicius de Souza Oliveira Gilcéa Teixeira Fontana Boone Luan Luciano dos Santos Pereira Natália Cristina Barbosa moura Ana Beatriz mamedes Piffer Anderson mathias Holtz lusiane de Sousa Ferreira Raquel Cetto Sampaio Federal Rural University of Rio de Janeiro Seropédica Brazil Center for Agricultural Sciences and Engineering Federal University of Espírito Santo Alegre Brazil Campus Itapina Federal Institute of Espírito Santo Colatina Brazil State University Paulista “Júlio de mesquita Filho” Botucatu Brazil

Bromeliaceae are important in ecological restoration, showing easy adaptation to different environments, and constantly interacting with each other through ecological relationships, whose effects may or may not benefit the species involved. The hypothesis tested whether the population density of Hohenbergia augusta is higher in areas at a more advanced successional stage (brown trail), since the species is typical of more structured forest environments, occurring especially in the lower strata of the forest. Six plots of 10 meters (6 × 10 m) were installed, parallel to the brown and yellow trails, and with a distance of 5 m from the edge. Plots were allocated alternately between the two sides of the trail, 10 meters apart from each other when on the same side. In each plot, all H. augusta (Vell.) E. morren bromeliads were sampled, without a minimum inclusion criterion, provided they were epiphytic phorophytes. The logarithm of the value was used for data normalization and later, the data were tested in a student’s t-test. The study pointed out that the highest population density of H. augusta occurred in the brown trail because the area is in a more advanced successional stage.

关键词： Bromeliads Atlantic Forest Ecological Restoration

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What Do Seedlings Like? The Relationship between Seedling Richness and Abundance with Abiotic Factors

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Agricultural Sciences 2023年第6期14卷 767-774页

作者： Johnatan Jair de Paula marchiori Vinicius de Souza Oliveira Eduarda Carriço Ana Clara Bayer Bernabé Anderson mathias Holtz Ronilda Lana Aguiar Ana Beatriz mamedes Piffer Gilcéa Teixeira Fontana Boone Ricardo Amaro de Sales lusiane de Sousa Ferreira Department of Environmental Sciences/Phytotechnics Department Federal University Rural of Rio de Janeiro-Seropédica Rio de Janeiro Brazil Center for Agricultural Sciences and Engineering Federal University of Espírito Santo Alegre Espírito Santo Brazil Laboratory of Entomology and Acarology Federal Institute of Espírito Santo Campus Itapina Colatina Espírito Santo Brazil Agriculture Department State University Paulista “Júlio de Mesquita Filho” Botucatu S&#227o Paulo Brazil

Natural regeneration is the interaction of natural processes to restore the forest ecosystem. Its dynamics are influenced by the intensity and extent of a series of abiotic and biotic factors, which may be intrinsic or extrinsic. Knowing the importance of establishing natural regeneration within forest ecosystems, this work aimed to evaluate whether litter depth and trail distance influenced seedling abundance and richness in a forest fragment undergoing natural restoration. The hypothesis tested in this research was that abiotic factors influence the natural regeneration of this forest since they are factors that are directly linked to seed germination and seedling establishment. 30 plots of 1 m2 were randomly analyzed within the forest located on the brown trail. A millimeter ruler was used to diagnose the litter depth and a measuring tape to measure the distance from the plot to the edge. In each plot the seedlings were morpho-specified and each morphospecies had the number of individuals counted. Linear regression tests were performed to assess the relationships between species richness and trail distance and litter depth. The same was done for species abundance. All results showed that there is no relationship pattern between any of the variables. Other factors also influence the regeneration of a forest, such as luminosity and seed bank. Furthermore, litter depth is related to the successional stage of the forest. It was concluded that the abiotic factors tested do not influence the regeneration of the study area.

关键词： Abiotic Factors Natural Regeneration Forest Ecosystem

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