Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/194229
Type: Artigo de periódico
Title: Pathological Changes Induced By Phtx1 From Phoneutria Nigriventer Spider Venom In Mouse Skeletal Muscle In Vitro.
Author: Mattiello-Sverzut, A C
Fontana, M D
Diniz, C R
da Cruz-Höfling, M A
Abstract: The 'armed' spider Phoneutria nigriventer is responsible for most human accidents involving spiders in Brazil. The effects of fraction Tx1 (PhTx1) from the venom of this spider were investigated by physiological and morphological methods using the mouse phrenic nerve-diaphragm preparation. PhTx1 (1 and 5 microg) did not affect the twitch tension of muscle fibers under indirect electrical stimulation. At this same concentration, PhTx1 also did not alter the miniature end-plate potential (mepp) frequency and amplitude, nor did it change the resting membrane potential 60 min after addition to the preparation. Light microscopy (LM) revealed that in muscles incubated with PhTx1 a number of fibers were morphologically altered, as evidenced by microvacuolization and myofibril hypercontraction and loss within 15 min after toxin administration. Transmission electron microscopy (TEM) showed sarcoplasmic reticulum swelling, disorganization of the sarcomeres and mitochondrial damage, and occasionally, sarcolemmal discontinuities with a persisting basal membrane. The intra-muscular fascicles of the phrenic nerve showed myelinated axons with vacuolated myelin sheaths as well as peri- and intra-axoplasmic vacuoles. The neuromuscular junction changes were variable, but were rarely severe. Thus, although PhTx1 did not depolarize or hyperpolarize the neuromuscular junction, it was nevertheless toxic to a restricted number of muscle fibers and nerve structures. The site of action of PhTx1 may involve the sarcolemma and axolemma as suggested by the morphological abnormalities which could reflect hydroelectrolytic disturbances.
Subject: Animals
Diaphragm
Electric Stimulation
In Vitro Techniques
Male
Membrane Potentials
Mice
Microscopy, Electron
Mitochondria
Muscle, Skeletal
Neuromuscular Junction
Neuropeptides
Phrenic Nerve
Spider Venoms
Spiders
Synaptic Vesicles
Rights: fechado
Identifier DOI: 
Address: http://www.ncbi.nlm.nih.gov/pubmed/9723834
Date Issue: 1998
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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