Assessment of reactive oxygen species production in cultured equine skeletal myoblasts in response to conditions of anoxia followed by reoxygenation with or without exposure to peroxidases.

Objective—To culture equine myoblasts from muscle microbiopsy specimens, examine
myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by
reoxygenation, and assess the effects of horseradish peroxidase (HRP) and myeloperoxidase
(MPO) on ROS production.
Animals—5 healthy horses (5 to 15 years old).
Procedures—Equine skeletal myoblast cultures were derived from 1 or 2 microbiopsy
specimens obtained from a triceps brachii muscle of each horse. Cultured myoblasts were
exposed to conditions of anoxia followed by reoxygenation or to conditions of normoxia
(control cells). Cell production of ROS in the presence or absence of HRP or MPO was
assessed by use of a gas chromatography method, after which cells were treated with a
3,3′-diaminobenzidine chromogen solution to detect peroxidase binding.
Results—Equine skeletal myoblasts were successfully cultured from microbiopsy specimens.
In response to anoxia and reoxygenation, ROS production of myoblasts increased by
71%, compared with that of control cells. When experiments were performed in the presence of HRP or MPO, ROS production in myoblasts exposed to anoxia and reoxygenation
was increased by 228% and 183%, respectively, compared with findings for control cells.
Chromogen reaction revealed a close adherence of peroxidases to cells, even after several
washes.
Conclusions and Clinical Relevance—Results indicated that equine skeletal myoblast
cultures can be generated from muscle microbiopsy specimens. Anoxia-reoxygenation–
treated myoblasts produced ROS, and production was enhanced in the presence of peroxidases.
This experimental model could be used to study the damaging effect of exercise on
muscles in athletic horses.