Effects of electroacupuncture on muscle state and electrophysiological changes in rabbits with lumbar nerve root compression.

OBJECTIVE: To observe the effects of electroacupuncture on force-displacement value (FDV) of muscle state and electrophysiology of the muscle in rabbits with lumbar nerve root compression. METHODS: Thirty New Zealand white rabbits were randomly divided into a control, a model, an electro-acupuncture acupoints (EAA), a medication, and an electro-acupuncture un-acupoints (EAU) group. All rabbits except those in the control group were subject to modeling (surgical lumbar nerve root compression). The control group was sham-operated without nerve root compression. The EAA group received electro-acupuncture at bilateral Shenshu (BL23) and Dachangshu (BL25) that were located 1.5 cun lateral to the posterior midline on the lower border of the spinous process of the 2nd and 4th lumbar vertebra, respectively. The EA was 15 mm deep and the frequency was 2 Hz. Each session lasted for 20 min per day for a total of 14 times. The medication group was treated with Loxoprofen sodium by gastrogavage at 4 mg/kg per day for 14 days. The EAU group received electro-acupuncture identical to the EAA group with regard to the treatment frequency and duration except a different acupoint at the tip of rabbit tail. Muscle states were determined by measuring FDVs of the bilateral biceps femoris using the Myotonometer® fast muscle state detector. Meanwhile, the prolonged and non-prolonged insertion potentials were measured by electromyography before and after modeling and after treatment. Latency, amplitude (Amp) of evoked potential, motor nerve conduction velocity (MNCV) were also determined after treatment. RESULTS: (1) After modeling, FDVs of right side activation (RSA, P=0.003) and right side relaxation (RSR) in the model group (P=0.000) were significantly decreased in comparison to the control group. The number of rabbits with non-prolonged insertion potentials in the model group was also significantly decreased (P=0.015) in comparison to the control group. (2) After treatment, FDVs of RSR were significantly increased in the EAA (P=0.000) and medication groups (P=0.018) in comparison to the model group. The increase in FDVs of RSR in the EAA group was significantly higher than that in EAU (P=0.000) and medication groups (P=0.002). MNCV in the model group was reduced compared with the control group (P=0.000). The reduction in MNCV after modeling was reversed in the EAA group (P=0.000) and medication group (P=0.008) after treatment and the increases were significant in both treatment groups in comparison to the model group. The EAA group had a greater MNCV recovery than the medication group (P=0.022). CONCLUSION: Electro-acupuncture could improve the rehabilitation and regeneration of FDVs and the electrophysiology index of the muscle with nerve control impairment.

[Correlation study on effects of electroacupuncture on the muscle condition and MNCV in rabbits with lumbar nerve root compression].

OBJECTIVE: To observe the effects of electroacupuncture on the muscle condition and electrophysiology of the muscle in rabbits with lumbar nerve root compression and to explore potential mechanisms. METHODS: Twenty-four New Zealand white rabbits were randomly divided into a normal group, a model group, a medication group and an electroacupuncture group. The rabbit model with lumbar nerve root compression was established in the model group, the medication group and the electroacupuncture group. The model and the treatment were not produced in the normal group. The medication group was treated with oral administration of Loxoprofen tablets at a dose of 30 mg each day for 14 days. The electroacupuncture group was treated with electroacupuncture at "Jiaji" (EX-B 2) of L5 and L6 for 14 days. The hibateral muscle condition before and after making model and after treatment was detected and the electromyogram and the nerve conduction velocity (NCV) were observed. RESULTS: The spontaneous potential and the insertion potential were increased in the model group, the medication group and the electroacupuncture group after making model. The value of the activation and the relaxed condition of the strength-creep (ARCSC) in the right muscle was significantly decreased. The motor nerve conduction velocity (MNCV) and the wave amplitude of evoked potential (WAEP) were significantly decreased in the model group, the medication group and the electroacupuncture group after treatment, but the value of MNCV and WAEP in the electroacupuncture group, and ARCSC in the right muscle in the electroacupuncture group and the medicine group were closed to those level in the normal group, among them, the relaxed condition in the electroacupuncture group was more close to the level in the normal group. CONCLUSION: Electroacupuncture can improve the strength-creep condition of the muscle that damage nerve place controls and the electrophysiology of the muscle can recover the MNCV and the wave amplitude of evoked potential in the compression nerve root.