ABSTRACT
<p><b>OBJECTIVE</b>To explore the mechanism of electroacupuncture on improving insulin resistance of rat from aspects of morphology and function of mitochondrial in quadriceps femoris.</p><p><b>METHODS</b>Forty-eight 8-week Wistar rats (female and male in half) were randomly divided into a normal group (16 rats, group A), a model control group (16 rats, group B), a model plus electroacupuncture (EA) group (8 rats, group C) and a model plus sham acupoint EA group (8 rats, group D). Group A was given with basic diet while high-fat diet was applied in the group B, group C and group D for 8 weeks to establish model of insulin resistance. After the model establishment, "Guanyuan" (CV 4), "Zhongwan" (CV 12), "Zusanli" (ST 36) and "Fenglong" (ST 30) were selected according to acupoint combination of manifestation-root in the group C, while four points in non-meridian area where 1 to 2 mm next to the acupoints used in group C were selected in the group D. The treatment was given 15 min per time with 1 mA of intensity and 2 Hz in frequency, 5 times per week for totally 8 weeks. The transmission electron microscope was adopted to observe mitochondria structure, and chemical colorimetry was used to test the activity of adenosine triphosphate (ATP) synthase and phosphomolybdic acid colorimetry was applied to measure the content of ATP.</p><p><b>RESULTS</b>After the treatment, the body mass was (401.63 +/- 109.81) g in the group B, which was significantly higher than (305.88 +/- 62.72) g in the group A (P < 0.05); morphological structure of mitochondrion was damaged, showing swelling and deformation; the activity of ATP synthase was decreased (P < 0.05) and the content of ATP in tissue of quadriceps femoris was also obviously lowered (P < 0.05). The body mass was (294.13 +/- 53.78) g in the group C, which was significantly lower than that in the group B (P < 0.05); the damaged mitochondrion was restored and merged among each other; the activity of ATP synthase was increased (P < 0.05); the content of ATP in tissue of quadriceps femoris was obviously lifted (P < 0.05). The results in group D were not different from those in group B.</p><p><b>CONCLUSION</b>The electroacupuncture with manifestation-root acupoint combination could improve the recovery of damaged structure of mitochondrion and promote the merge among each other, which could enhance oxidizing capacity, lower body mass and improve synthetic rate of ATP.</p>