Objective To observe the effect of different strength of electroacupuncture(EA)stimulation on gastrointestinal motility and Ras homolog gene family member(RhoA)/Rho associated coiled-coil forming protein kinase(ROCK)signaling in diabetic gastroparesis(DGP)rats

so as to reveal the underlying mechanisms of EA for improving DGP.Methods Sixty SD rats were randomly and equally divided into blank control

DGP model

weak EA

medium EA

and strong EA groups(n=12 rats in each).The DGP model was established by intraperitoneal injection of streptozotocin(STZ

55 mmol/kg

2%)and high-sugar and high-fat fodder feeding for 8 weeks.EA(0.12

0.24

0.36 mA

20 Hz/100 Hz)was applied to"Zusanli"(ST 36)

"Sanyinjiao"(SP 6)and"Liangmen"(ST 21)for 20 min

once daily for 15 successive days.Blood glucose levels were measured weekly with blood glucose meter and blood glucose test paper.Fecal phenol red excretion method was used to display gastric emptying and small intestinal propulsion function.The expression of RhoA protein in the gastric antral smooth muscle tissue was detected by immunohistochemistry and Western blot(WB)

separately

and that of ROCK

myosin phosphatase target subunit 1(MYPT 1)and phosphorylated(p)-MYPT 1 proteins in gastric antrum detected by WB.Results Compared with the blank control group

the gastric emptying rate and small intestine propulsion rate of the model group were significantly decreased(P<0.05)

and the blood glucose level was remarkably increased(P<0.05).Moreover

the expression levels of RhoA

ROCK

MYPT 1 and p-MYPT 1 proteins in the gastric antrum were significantly down-regulated relevant to the control group(P<0.05).After administration of EA

the decreased gastric emptying rate and intestinal propulsion rate

and the down-regulated expression of RhoA

ROCK

MYPT 1 and p-MYPT 1 proteins were significantly increased in the strong

medium and weak EA stimulation groups(P<0.05).Comparison among the3 EA groups showed that the strong stimulation was significantly superior to weak stimulation in up-regulating the expression of RhoA

ROCK

MYPT 1 and p-MYPT 1 proteins

and obviously superior to the medium stimulation in up-regulating RhoA and MYPT 1 protein levels(P<0.05)

while the medium stimulation was significantly stronger than the weak stimulation in up-regulating the expression of ROCK

MYPT 1 and p-MYPT 1 proteins(P<0.05).There were no significant differences among the 3 EA groups in up-regulating the gastric emptying rate and small intestinal propulsion rate

and between the strong stimulation and medium stimulation in the expression levels of ROCK and p-MYPT 1 proteins(P>0.05).Conclusion Electroacupuncture stimulation of ST 36-SP 6-ST 21 at 0.12

0.24 and 0.36 mA can promote the gastrointestinal motility in DGP rats

which may be associated with its effects in enhancing RhoA/ROCK signaling in the gastric antral smooth muscle at different degrees.