Skeletal muscle fiber hypercontraction induced by Bothrops asper myotoxic phospholipases A₂ ex vivo does not involve a direct action on the contractile apparatus.

ABSTRACT: Myonecrosis is a frequent clinical manifestation of envenomings by Viperidae snakes, mainly caused by the toxic actions of secreted phospholipase A₂ (sPLA₂) enzymes and sPLA₂-like homologs on skeletal muscle fibers. A hallmark of the necrotic process induced by these myotoxins is the rapid appearance of hypercontracted muscle fibers, attributed to the massive influx of Ca²⁺ resulting from cell membrane damage. However, the possibility of myotoxins having, in addition, a direct effect on the contractile machinery of skeletal muscle fibers when internalized has not been investigated. This question is here addressed by using an ex vivo model of single-skinned muscle fibers, which lack membranes but retain an intact contractile apparatus. Rabbit psoa

SUBMITTER: Lopez-Davila AJ 

PROVIDER: S-EPMC10499977 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature