In Vitro Studies Of The Ultrastructural Changes Induced By Guanidine In The Nerves, Muscle Fibers And Neuromuscular Junction Of The Mouse Diaphragm.

dc.creatorCruz-Höfling, M A
dc.creatorRodrigues-Simioni, L
dc.date1998-May
dc.date2015-11-27T12:19:11Z
dc.date2015-11-27T12:19:11Z
dc.date.accessioned2018-03-29T00:52:42Z
dc.date.available2018-03-29T00:52:42Z
dc.identifierGeneral Pharmacology. v. 30, n. 5, p. 705-11, 1998-May.
dc.identifier0306-3623
dc.identifier
dc.identifierhttp://www.ncbi.nlm.nih.gov/pubmed/9559322
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/194151
dc.identifier9559322
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1294384
dc.description1. The incubation of mouse isolated diaphragm with guanidine for 60 min produced ultrastructural changes in the neuromuscular junction, the intramuscular fascicles of the phrenic nerve and the skeletal muscle fibers. 2. The main morphological characteristics of both the end terminals and the nerve fibers were a swollen appearance and an electron-lucent axoplasm. In addition, the mitochondria in these regions were markedly swollen and showed a rarefaction of their cristae as well as a washed aspect of their matrix. Occasional periaxonal vacuoles were present in the myelinated axons. There was a reduction in the number of synaptic vesicles, which was accentuated by the enlarged areas of the majority of the terminals. 3. Muscle cells underwent a range of morphological alterations in the myofibrils and mitochondria. The most drastic type of necrosis affecting these cells was complete dissolution of the myofibrils, which resulted in an apparently empty cell with only the sarcolemma and a few mitochondria remaining intact. 4. Tetrodotoxin was unable to provide total protection against these guanidine-induced changes. 5. We conclude that the ultrastructural effects evoked by guanidine may be associated with modifications in the permeability of the axolemmal and sarcolemmal membranes as a result of changes in ionic conductance. Such ionic disturbances also interfere with the metabolism of mitochondria and the sarcoplasmic reticulum and may account for the well-known inhibitory effect of guanidine on K+ channels and consequently on Ca2+ and Na+ conductances. 6. It is also suggested that the guanidine-induced alterations in the presynaptic and postsynaptic sites could have independent mechanisms of action.
dc.description30
dc.description705-11
dc.languageeng
dc.relationGeneral Pharmacology
dc.relationGen. Pharmacol.
dc.rightsfechado
dc.rights
dc.sourcePubMed
dc.subjectAnimals
dc.subjectDiaphragm
dc.subjectGuanidine
dc.subjectMale
dc.subjectMice
dc.subjectMicroscopy, Electron
dc.subjectMuscle Fibers, Skeletal
dc.subjectNeuromuscular Junction
dc.subjectNeurons
dc.subjectParasympathomimetics
dc.titleIn Vitro Studies Of The Ultrastructural Changes Induced By Guanidine In The Nerves, Muscle Fibers And Neuromuscular Junction Of The Mouse Diaphragm.
dc.typeArtículos de revistas


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