Consulta: subjectFacets:"Tetanic fade"
Registros recuperados: 5
Data/hora: 11/06/2024 14:56:35

L- and DL-carnitine induce tetanic fade in rat neuromuscular preparation
Provedor de dados: 56
Autores: Lopes,G.; Bazotte,R.B.; Curi,R.; Alves-Do-Prado,W.
Carnitine, a structurally choline-like metabolite, has been used to increase athletic performance, although its effects on neuromuscular transmission have not been investigated. It is present in skeletal muscle and its plasma levels are about 30 to 90 µM. Using rat phrenic nerve diaphragm preparations indirectly and directly stimulated with high rate pulses, D-carnitine (30 and 60 µM), L-carnitine (60 µM) and DL-carnitine (60 µM) were shown to induce tetanic fade (D-carnitine = 19.7 ± 3.1%, N = 6; L-carnitine = 16.6 ± 2.4%, N = 6; DL-carnitine = 14.9 ± 2.1%, N = 6) without any reduction of maximal tetanic tension. D-carnitine induced tetanic fade in neuromuscular preparations previously paralyzed with d-tubocurarine and directly stimulated. The effect was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carnitine; Skeletal muscle; Tetanic fade; Atropine.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000900017

Antagonism by hemoglobin of effects induced by L-arginine in neuromuscular preparations from rats
Provedor de dados: 56
Autores: Ambiel,C.R.; Alves-Do-Prado,Wilson.
Nitric oxide (NO)-synthase is present in diaphragm, phrenic nerve and vascular smooth muscle. It has been shown that the NO precursor L-arginine (L-Arg) at the presynaptic level increases the amplitude of muscular contraction (AMC) and induces tetanic fade when the muscle is indirectly stimulated at low and high frequencies, respectively. However, the precursor in muscle reduces AMC and maximal tetanic fade when the preparations are stimulated directly. In the present study the importance of NO synthesized in different tissues for the L-Arg-induced neuromuscular effects was investigated. Hemoglobin (50 nM) did not produce any neuromuscular effect, but antagonized the increase in AMC and tetanic fade induced by L-Arg (9.4 mM) in rat phrenic nerve-diaphragm...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Skeletal muscle; Nitric oxide; Tetanic fade; L-arginine; D-arginine; Hemoglobin.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000400017

4-Aminopyridine inhibits the neuromuscular effects of nitric oxide and 8-Br-cGMP
Provedor de dados: 56
Autores: Queiroz,R.N.; Ramos,E.R.P.; Alves-Do-Prado,W.
The effects induced by nitric oxide (NO) in different tissues depend on direct and/or indirect interactions with K+ channels. The indirect interaction of NO is produced by activation of guanylyl cyclase which increases the intracellular cGMP. Since NO, cGMP and 4-aminopyridine alone induce tetanic fade and increase amplitude of muscular contractions in isolated rat neuromuscular preparations, the present study was undertaken to determine whether or not the neuromuscular effects of NO and 8-Br-cGMP can be modified by 4-aminopyridine. Using the phrenic nerve and diaphragm muscle isolated from male Wistar rats (200-250 g), we observed that L-arginine (4.7 mM) and 8-Br-cGMP (18 µM), in contrast to D-arginine, induced an increase in the amplitude of muscle...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: L-arginine; Nitric oxide; CGMP; Skeletal muscle; Tetanic fade; K+ channel.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000700016

Atropine and ODQ antagonize tetanic fade induced by L-arginine in cats
Provedor de dados: 56
Autores: Cruciol-Souza,J.M.; Alves-Do-Prado,W.
Although it has been demonstrated that nitric oxide (NO) released from sodium nitrite induces tetanic fade in the cat neuromuscular preparations, the effect of L-arginine on tetanic fade and its origin induced by NO have not been studied in these preparations. Furthermore, atropine reduces tetanic fade induced by several cholinergic and anticholinergic drugs in these preparations, whose mechanism is suggested to be mediated by the interaction of acetylcholine with inhibitory presynaptic muscarinic receptors. The present study was conducted in cats to determine the effects of L-arginine alone or after pretreatment with atropine or 1H-[1,2,4]oxadiazole [4,3-a]quinoxalin-1-one (ODQ) on neuromuscular preparations indirectly stimulated at high frequency. Drugs...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Atropine; Tetanic fade; Skeletal muscle; Nitric oxide; Muscarinic receptors.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001000015

Effects of L-arginine on the diaphragm muscle twitches elicited at different frequencies of nerve stimulation
Provedor de dados: 56
Autores: Queiroz,R.N.; Alves-Do-Prado,Wilson.
In rats, the nitric oxide (NO)-synthase pathway is present in skeletal muscle, vascular smooth muscle, and motor nerve terminals. Effects of NO were previously studied in rat neuromuscular preparations receiving low (0.2 Hz) or high (200 Hz) frequencies of stimulation. The latter frequency has always induced tetanic fade. However, in these previous studies we did not determine whether NO facilitates or impairs the neuromuscular transmission in preparations indirectly stimulated at frequencies which facilitate neuromuscular transmission. Thus, the present study was carried out to examine the effects of NO in rat neuromuscular preparations indirectly stimulated at 5 and 50 Hz. The amplitude of muscular contraction observed at the end (B) of a 10-s...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Skeletal muscle; Nitric oxide; L-arginine; Neuromuscular transmission; Tetanic fade; S-nitroso-N-acetylpenicillamine; Superoxide dismutase.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000600020