A 5-g muscle sample was homogenized in 25 ml of phosphate
buffer (0.05 M, pH=7) and centrifuged at 4 °C for 2 min at 7000×g.
The supernatant fraction was filtered through four layers of
cheesecloth and used to determine catalase and GSH-Px activities.
Appropriate amounts of NaCl and KCl were added in the enzyme
extraction buffer in order to equalize the ionic strength in the reaction
mixtures.