[Effect of electroacupuncture intervention on expression of extracellular matrix collagen and metabolic enzymes]

To observe the effect of electroacupuncture (EA) at "Dazhui" (GV 14) on the contents of extracellular matrix (ECM), collagen type II (COL-II), collagen type V (COL-V), matrix metalloproteinase (MMP)-13, tissue inhibitor of metalloproteinase (TIMP)-1 in rats with cervicovertebral disc degeneration so as to explore its mechanism underlying relief of intervertebral disc degeneration.

A total of 28 SD rats were randomly divided into sham group (n = 7), model group (n = 7), EA group (n = 7) and medication group (n = 7). The model of cervical intervertebral disc degeneration was established by trans-section of the deep neck splenius, the longest muscles of head, neck costocervicalis, head semi-spinatus muscle, supraspinous ligament and interspinal ligaments of cervical 2-7 segments, etc. to produce imbalance between the dynamic and static force. EA was applied to "Dazhui" (GV 14) for 30 min, once daily for 28 days, with a 2 days' interval between two courses. Animals of the medication group were treated by oral administration of meloxicam tablets (0.75 mg/kg) once daily for 28 days, with a 2 days' interval between two courses. Immunohistochemistry was used to measure the expression of ECM, COL- II, COL-V, MMP-13 and TIMP-1 in the cervicovertebral disc tissue.

Compared with the sham group, the expression levels of ECM and COL-II proteins in the cervicovertebral disc tissue were significantly decreased in the model group (P < 0.01), while COL-V and MMP-13 expression levels in the model group were significantly increased (P < 0.01, P < 0.05). Compared with the model group, both ECM and COL-Il expression levels were considerably increased in the EA group and medication group (P < 0.01), while COL-V and MMP-13 expression levels were considerably down-regulated (P < 0.01, P < 0.05). No significant differences were found among the four groups in TIMP-1 expression levels (P > 0.05).

EA of "Dazhui" (GV 14) can effectively regulate extracellular matrix system in rats with cervical intervertebral disc degeneration, which is possibly related to its effect in relieving cervical spondylosis.