We assessed the contractile force of the fast and slow muscles using sciatic nerve electrical stimulation. The EDL muscle and SOL muscle were selected as examples of fast and slow muscles, respectively. A fast muscle is mainly composed of type 2 fibers, while a slow muscle is composed of type 1 fibers. The experimental method was as described by Shilveira and Fortes [29 (link), 30 (link)].
The animals were anesthetized by the intraperitoneal injection of medetomidine (0.15 mg/kg), midazolam (2 mg/kg), and butorphanol (2.5 mg/kg). The level of anesthesia was judged by the loss of the pedal withdrawal reflex. Thereafter, their limbs were fixed on a perfusion platform and we incised the right hind limb skin and subcutaneous tissue to expose the sciatic nerve. Two platinum electrodes were attached to the hemi-lateral sciatic nerve. The insertions of the ipsilateral EDL and SOL muscle were cut and connected to a force transducer (45196A; NEC Sanei Instruments Inc., Tokyo, Japan). The resting length and stimulation voltage were adjusted to induce maximum contraction. The electrical stimulator (SEN-3301; NIHON KOHDEN, Tokyo, Japan) and isolator (SS-102 J; NIHON KOHDEN, Tokyo, Japan) were set with an impulse frequency of 1 Hz and duration every 0.5 ms. Five contractions were performed to determine the mean force (mN).
The animals were anesthetized by the intraperitoneal injection of medetomidine (0.15 mg/kg), midazolam (2 mg/kg), and butorphanol (2.5 mg/kg). The level of anesthesia was judged by the loss of the pedal withdrawal reflex. Thereafter, their limbs were fixed on a perfusion platform and we incised the right hind limb skin and subcutaneous tissue to expose the sciatic nerve. Two platinum electrodes were attached to the hemi-lateral sciatic nerve. The insertions of the ipsilateral EDL and SOL muscle were cut and connected to a force transducer (45196A; NEC Sanei Instruments Inc., Tokyo, Japan). The resting length and stimulation voltage were adjusted to induce maximum contraction. The electrical stimulator (SEN-3301; NIHON KOHDEN, Tokyo, Japan) and isolator (SS-102 J; NIHON KOHDEN, Tokyo, Japan) were set with an impulse frequency of 1 Hz and duration every 0.5 ms. Five contractions were performed to determine the mean force (mN).
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