ULTRASTRUCTURAL PATHOLOGY, vol.39, no.3, pp.169-176, 2015 (SCI-Expanded)
ABSTRACT
The aim of this study was to investigate the myotoxic effects of bupivacaine, ropivacaine, and
levobupivacaine which were applied intramuscularly to rat skeletal muscle. Forty Wistar-Albino rats were
divided into four groups. In the study, .5% bupivacaine (Group B), .5% ropivacaine (Group R), .5%
levobupivacaine (Group L), or .9% normal saline (Group SF) was applied intramuscularly to the right
gastrocnemius muscle of rats. The rats in each group were sacrificed on the second day after injection.
Sections of muscle samples were stained with hematoxylin–eosin for light microscopic investigation and
prepared for the evaluation of ultrastructural changes in the subcellular level with transmission electron
microscopy. All three local anesthetic agents caused qualitatively similar skeletal muscle damage. The most
observed muscle damage was in Group B, muscle damage of Group R was less than that of Group B, and the
least damage was seen in Group L quantitatively. Electron microscopic examination of each group that
caused cellular damage was qualitatively similar. The most subcellular damage was observed in the group
receiving bupivacaine, less was seen in the ropivacaine group, and the least was observed in the
levobupivacaine group. The results indicated that bupivacaine caused more myotoxic damage than the other
two agents in the skeletal muscle of rats and that levobupivacaine caused less myotoxic damage than both
bupivacaine and ropivacaine at the cell and tissue levels.
Keywords:
Local anesthetic, myotoxicity, transmission electron microscopy
Histological changes caused by local anesthetics in the
striated muscle tissue were described for the first time
by Brun in 1959 [1]. Drug- and dose-dependent
myonecrosis of skeletal muscle tissue and the consequent
severe muscular dysfunction due to the
application of