Objective To observe the effect of electroacupuncture(EA)stimulation of"Jiaji"(EX-B 2)on the expression of matrix metalloproteinase-13(MMP-13)and tissue inhibitor of metalloproteinase-1(TIMP-1)proteins in the lumbar disc in rabbits with lumbar intervertebral disc degeneration so as to explore its mechanism in relieving intervertebral disc degeneration.Methods A total of 36New Zealand rabbits were randomly divided into normal

sham operation(sham)

model

and EA groups

with 9rabbits in each group.The lumbar intervertebral disc degeneration model was established by using a custom-made external loading device to axially compress the lumbar discs(L 4

L 5)for 28days in reference to Kroeber and colleagues' methods.After modeling

EA stimulation(2Hz/15Hz

1-2mA)was applied to bilateral"Jiaji"(EX-B 2)areas for 20min

once daily for 28days.The expression levels of MMP-13and TIMP-1proteins of the lumbar intervertebral disc(L 4-L 5)tissues were assayed by Western blot and immunoflorescence methods

separately.Results Compared to the normal and sham groups

MMP-13expression levels at the time-points of day 28in the model group

on day 28(pre-EA)in the EA group were significantly up-regulated(P<0.01);and TIMP-1expression levels on day 28in both model and EA groups were significantly decreased(P<0.01).Following EA treatment

the expression level of MMP-13was notably lower in the EA group than in the model group

and that of TIMP-1was remarkably higher in the EA group than in the model group(P<0.01).No significant differences were found in the expression levels of MMP-13and TIMP-1from day 1to day 56in the same one group of both normal and sham groups

and between these two groups(P>0.05).Conclusion Electroacupuncture at"Jiaji"(EX-B 2)can effectively suppress intervertebral disc degeneration induced up-regulation of MMP-13protein and down-regulation of TIMP-1protein in the disc tissue in rabbits

which may contribute to its effect in bettering lumbago in clinic.