Objective To observe the effect of electroacupuncture(EA)of"Jiaji"(EX-B 2)on limb locomotor function and expression of Ras homolog gene family member A(RhoA)

Rho-associated kinase Ⅱ(ROCK Ⅱ)and myosin light chain(MLC)proteins in the anterior horn of spinal cord in acute spinal cord injury(ASCI)rats

so as to explore its mechanisms underlying improvement of SCI-induced limb locomotor dysfunction.Methods Forty-eight female Wistar rats were randomly divided into sham operation(sham)

ASCI model(model)

EA EX-B 2(EA)and ROCK inhibitor(Fasudil)groups which were further divided into 14 dand 28 dsubgroups(n=6 in each).The ASCI model was made by using weight drop striking method.Three hours after modeling

EA(100 Hz

0.4

0.6 mA)was applied to EX-B 2(T 9

T 11)for 30 min

once daily for 14 dand 28 d

respectively.The ROCK inhibitor(hydrochloride Fasudil

10 mg/kg)was administrated by intraperitoneal injection immediately after modeling

once a day

continuously for 14 dor 28 d.The expression of RhoA

ROCK Ⅱ and MLC proteins in the spinal cord anterior horn tissue(T 10)was detected by immunohistochemistry.The rats' hindlimb locomotor function was assessed according to Basso

Beattie and Bresnahan(BBB)locomotor rating scale(21-points).Results After ASCI

the BBB scores were significantly lower in the model group than in the sham group on day 14 and 28(P<0.05)

and obviously higher in the EA and inhibitor groups than in the model group(P<0.05)

suggesting an improvement of the hindlimb locomotor function after EA intervention or suppression of ROCK.Immunohistochemical results indicated that the numbers of RhoA

ROCK Ⅱ and MLC immune-reaction positive cells in the anterior horn of spinal cord were significantly more in the model group than in the sham group(P<0.05)

and remarkably decreased in both EA and inhibitor groups on day 14 and 28 relevant to the model group(P<0.05).The therapeutic effects of EA were markedly weaker than those of inhibitor Fasudil in up-regulating BBB score and down-regulating the number of RhoA

ROCKⅡ and MLC positive cells(P<0.05).Conclusion EA of EX-B 2 can improve the hindlimb locomotor function in ASCI rats

which may be associated with its effect in down-regulating the expression of RhoA

ROCK Ⅱ and MLC proteins(i.e.

inhibiting the RhoA/ROCK signaling pathway)in the anterior horn of spinal cord.