Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/195082
Type: Artigo de periódico
Title: New Evidence For A Presynaptic Action Of Prednisolone At Neuromuscular Junctions.
Author: Dal Belo, Cháriston André
Leite, Gildo Bernardo
Fontana, Marcos Dias
Corrado, Alexandre Pinto
Zanandréa Baso, Ana Cristina
Moreno Serra, Carmen Sílvia
Oliveira, Antonio Carlos
Rodrigues-Simioni, Léa
Abstract: The action of prednisolone at the neuromuscular junction was studied in mouse isolated phrenic nerve-diaphragm and rat external popliteal/sciatic nerve-tibialis anterior muscle preparations. Prednisolone (0.03 mM and 0.3 mM) did not alter the twitch-tension in phrenic nerve-diaphragm preparations after 120 min, but increased the frequency (170 +/- 4%) and amplitude (200 +/- 13%) of miniature end-plate potentials. Quantal content was not influenced by the glucocorticoid treatment. Prednisolone (400 microg/kg) did not change the twitch-tension in rat external popliteal/sciatic nerve-tibialis anterior muscle preparations. However, this steroid (0.3 mM) prevented the neuromuscular blockade by d-tubocurarine (1.45 microM) in mouse preparations by 70 +/- 10% (P < 0.05). A similar effect (82 +/- 6% protection, P < 0.05) occurred in rats treated with prednisolone (400 microg/kg) before d-tubocurarine (225 microg/kg). In phrenic nerve-diaphragm preparations, prednisolone (0.3 mM) increased (13 +/- 4%, p < 0.05) the twitch-tension in the presence of beta-bungarotoxin (1 microM), and prevented the blockade produced by this toxin (0.15 microM) in its third phase of action. This presynaptic facilitatory effect may contribute to the usefulness of prednisolone in myasthenia gravis.
Subject: Animals
Diaphragm
In Vitro Techniques
Male
Membrane Potentials
Mice
Muscle, Skeletal
Neuromuscular Blocking Agents
Neuromuscular Junction
Phrenic Nerve
Prednisolone
Presynaptic Terminals
Rats
Rats, Wistar
Sciatic Nerve
Rights: fechado
Identifier DOI: 10.1002/mus.10132
Address: http://www.ncbi.nlm.nih.gov/pubmed/12115947
Date Issue: 2002
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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