Consulta: subjectFacets:"Neuromuscular junction"
Registros recuperados: 5
Data/hora: 16/06/2024 16:10:23

Morphometric and Morphological Analysis of Neuromuscular Junction Alterations in the Denervated Rat Diaphragm
Provedor de dados: International Journal of Morphology
Autores: Torrejais,M. M; Soares,J. C; Matheus,S. M. M; Mello,J. M; Francia-Farje,L. A. D; Vicente,E. J. D.
The morphological and structural alterations that occur in the neuromuscular junctions of the denervated rat diaphragm were studied. Fifteen adult male albino rats (Rattus norvegicus) aged about 60 days and with a mean weight of 200 g were used. Chronically denervated diaphragms were obtained and the animals were sacrificed after 4, 8 and 12 weeks of denervation. The left antimere of the diaphragm was denervated by section of the phrenic nerve and the right antimere was used as control. Each antimere was divided into three fragments: one was used for histochemical (nonspecific esterase) and morphometric study of neuromuscular junctions, and the other two were used for transmission and scanning electron microscopy (SEM) analysis. Histochemical analysis of...
Tipo: Journal article
Palavras-chave: Diaphragm; Neuromuscular junction; Denervation; Rat.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022009000400043

Rabbit antivenom efficacy against myotoxic and neurotoxic activities of Bothrops jararacussu venom and bothropstoxin-I
Provedor de dados: Journal of Venomous Animals and Toxins
Autores: Oshima-Franco,Y.; Leite,G. B.; Valério,A. A.; Hyslop,S.; Andriao-Escarso,S.; Giglio,J. R.; Prado-Franceschi,J.; Cruz-Höfling,M. A.; Rodrigues-Simioni,L.
Bothrops jararacussu venom and its major toxin bothropstoxin-I (BthTX-I) possess myotoxic and neurotoxic properties. The efficacy of a rabbit antivenom raised against B. jararacussu venom in the neutralization of physiological, biochemical, and morphological changes induced by the venom and its major toxin BthTX-I was studied in mouse isolated phrenic nerve-diaphragm (PND) and extensor digitorum longus (EDL) preparations. The times required for 50% neuromuscular blockade in PND and EDL preparations for venom were 70+11.5 (S.E.M., n=5) min and 58+8 (n=16) (50 mu g/mL), and for BthTX-I 31+6 (n=3) min and 30+3 (n=5) min (20 mu g/mL), respectively. After 120 min incubation, creatine kinase (CK) concentrations in solution containing the EDL preparations were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bothrops venom; Myotoxin; Neutralization; Neuromuscular junction; Histological analysis; Bothrops jararacussu.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-79302002000200004

Neuromuscular blocking action of the Theraphosa blondii spider venom
Provedor de dados: Journal of Venomous Animals and Toxins
Autores: Fontana,M. D.; Lucas,H. S. M.; Vital Brazil,O.
In 1919, Houssay and Negrete reported that venoms of Theraphosidae spiders induced neuromuscular blockade. In 1993, a purified toxin from Grammostola spider venom was found to block the P-type voltage-dependent calcium channel (VDCC), causing neuromuscular blockade. We studied the mode of action of Theraphosa blondii venom, a large Theraphosidae spider from Northern Brazil, Venezuela, and The Guyanas in mouse phrenic nerve-diaphragm preparation. This venom elicited a partially reversible neuromuscular blockade and did not depress directly evoked twitches or alter the membrane potential. Neostigmine produced only a poor antagonistic effect on partially blocked diaphragms. However, completely blocked miniature endplate potentials (m.e.p.ps) were reverted by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Spider venom; Mouse diaphragm preparation; Neuromuscular junction; Theraphosa blondii.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-79302002000200010

Purification and n-terminal sequencing of two presynaptic neurotoxic PLA2, neuwieditoxin-I and neuwieditoxin-II, from Bothrops neuwiedi pauloensis (jararaca pintada) venom
Provedor de dados: Journal of Venomous Animals and Toxins Including Tropical Diseases
Autores: Borja-Oliveira,C. R.; Kassab,B. H.; Soares,A. M.; Toyama,M. H.; Giglio,J. R.; Marangoni,S.; Re,L.; Rodrigues-Simioni,L.
Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (µBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10µg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0% (n=3; p&lt;0.05). NeuTX-I and NeuTX-II are probably...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chick biventer cervicis; Loose patch clamp; Nerve-muscle preparation; Neuromuscular junction; Neurotoxicity; PLA2 neurotoxin; Presynaptic action; Bothrops neuwiedi pauloensis; Neuwieditoxin-I; Neuwieditoxin-II.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992007000100008

Synaptic vesicle cycling is not impaired in a glutamatergic and a cholinergic synapse that exhibit deficits in acidification and filling
Provedor de dados: Brazilian Journal of Pharmaceutical Sciences
Autores: Abreu,Bento João; Leite,Luciana Ferreira; Oliveira,Débora Lopes; Amaral,Ernani.
The purpose of the present work was to investigate synaptic vesicle trafficking when vesicles exhibit alterations in filling and acidification in two different synapses: a cholinergic frog neuromuscular junction and a glutamatergic ribbon-type nerve terminal in the retina. These synapses display remarkable structural and functional differences, and the mechanisms regulating synaptic vesicle cycling might also differ between them. The lipophilic styryl dye FM1-43 was used to monitor vesicle trafficking. Both preparations were exposed to pharmacological agents that collapse ΔpH (NH4Cl and methylamine) or the whole ΔµH+ (bafilomycin), a necessary situation to provide the driving force for neurotransmitter accumulation into synaptic vesicles. The results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Synaptic vesicle; Acidification; Lipophilic styryl dye/use; Neuromuscular junction; Bipolar cell; Retina.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502012000100017