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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Ultrastructural aspects of mouse nerve-muscle preparation exposed to Bothrops jararacussu and Bothrops bilineatus venoms and their toxins BthTX-I and Bbil-TX: Unknown myotoxic effects

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Melare, Rodolfo ; Floriano, Rafael Stuani ; Gracia, Marta ; Rodrigues-Simioni, Lea ; da Cruz-Hofling, Maria Alice ; Rocha, Thalita
Total Authors: 6
Document type: Journal article
Source: MICROSCOPY RESEARCH AND TECHNIQUE; v. 79, n. 11, p. 1082-1089, NOV 2016.
Web of Science Citations: 2

Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve-muscle preparations exposed to Bothrops venoms and their phospholipase A(2) toxins (PLA(2)) can exhibit a neurotoxic pattern as increase in frequency of miniature endplate potentials (MEPPs) as well as in amplitude of end-plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA(2) toxins (BthTX-I and Bbil-TX) in mouse isolated nerve-phrenic diaphragm preparations (PND). Under transmission electron microscopy (TEM), PND preparations previously exposed to B. jararacussu and B. bilineatus venoms and BthTX-I and Bbil-TX toxins showed hypercontracted and loosed myofilaments; unorganized sarcomeres; clusters of edematous sarcoplasmic reticulum and mitochondria; abnormal chromatin distribution or apoptotic-like nuclei. The principal affected organelles, mitochondria and sarcoplasmic reticulum, were those related to calcium buffering and, resulting in sarcomeres and myofilaments hypercontraction. Schwann cells were also damaged showing edematous axons and mitochondria as well as myelin sheath alteration. These ultrastructural changes caused by both of Bothrops venoms and toxins indicate that the neuromuscular blockade induced by them in vitro can also be associated with nerve and muscle degeneration. (AU)

FAPESP's process: 11/00001-1 - Effects of pre-synaptic bothropic venoms and toxins on the neuromuscular junction: molecular aspects
Grantee:Thalita Rocha
Support type: Regular Research Grants