Objective To observe the effect of electroacupuncture(EA) at “Zusanli”(ST36)-“Sanyinjiao”(SP6) on glucose and lipid metabolism and insulin resistance(IR) in obese diabetic rats

so as to explore its mechanism underlying improvement of obesity diabetes. Methods SPF male rats were randomly divided into normal control

model

meridian-acupoint EA(acupoint)

non-meridian non-acupoint EA(non-acupoint)

and medication(metformin) groups

with 10 rats in each group. The diabetes model was established by feeding the rats with high-fat diet for 8 weeks. EA(1.5 mA

10 Hz/100 Hz) was applied to unilateral ST36 and SP6 for 20 min

once daily(except Sundays) for 4 weeks. Rats of the medication group were treated by gavage of metformin(300 mg/kg) once daily for 4 weeks(except Sundays). The body weight and length were measured and the Lee's index was calculated. The contents of total cholesterol(TC)

triglyceride(TG)

low density lipoprotein-cholesterol(LDL-C)

high density lipoprotein-cholesterol(HDL-C) in the plasma were detected by using a full-automatic biochemical analyzer. The content of fasting serum insulin(FINS) was assayed by using radioimmunoassay

the fasting blood glucose(FBG) was measured

and serum superoxide dismutase(SOD) activity by using xanthine oxidase method

serum malondialdehyde(MDA) by color method

serum glutathione peroxidase(GSH-Px) activity by indirect method

reactive oxygen species(ROS) by Dithio-bis-nitrobenzoic acid(DTNB) direct method

and the homeostasis model assessment of IR(HOMA-IR) and insulin sensitive index(ISI) were calculated. The expression levels of pancreatic tissue P66 shc mRNA and PKCβ mRNA were detected by using RT-PCR

and the histopathological changes of the liver and adipose tissues were observed after H.E. staining.Results Compared with the normal control group

the Lee's index

levels of FBG

FINS

HOMA-IR

TC

TG

LDL-C

MDA

ROS

and P66 shc mRNA and PKCβ mRNA expressions were significantly increased(P<0.05

P<0.01)

and ISI

HDL-C

SOD

GSH-Px significantly decreased(P<0.05

P<0.01) in the model group. After the interventions

the levels of Lee's index

levels of FBG

FINS

HOMA-IR

TC

TG

LDL-C

MDA

ROS

and expressions of P66 shc mRNA and PKCβ mRNA were remarkably down-regulated(P<0.05

P<0.01)

and those of ISI

HDL-C

SOD

and GSH-Px up-regulated(P<0.05

P<0.01) in both EA and medication groups. H.E. staining showed many white adipocytes in the adipose tissue

radial and cord-like arrangement of liver cells

and many of them with vacuoles in the cytoplasm of small vesicular lipid droplets in the model group; and relative reduction of white adipocytes in number

smaller in cell body

and no obvious abnormal changes of structure and arrangement of liver cells in the EA and medication groups.Conclusion EA of ST36 and SP6 can improve glucose and lipid metabolism and IR in obese diabetic rats

which may be related to its function in suppressing PKCβ/P66 shc signaling and oxidative stress.