[Animal experiment]-Inhibition of low-frequency electroacupuncture on DRG P2X3 receptors in type 2 diabetic neuralgia rats

  Objective: To observe the effect of low-frequency electroacupuncture (EA) on the pain threshold and P2X3 receptor expression of L5 dorsal root ganglion (DRG) in type 2 diabetic neuropathy (DNP) model rats.

  Method: Experiment 1: 50 SD rats were randomly divided into 8 control groups and 42 models. Through intraperitoneal injection of low-fat streptozotocin (STZ, 35mg/kg), the model was fed a high-fat and high-sugar diet, and a rat DNP model was established. The control group was fed regularly and given the same dose of citrate buffer injection. The rats that successfully established the model were further divided into model group (DNP group) and low-frequency electroacupuncture group (DNP + EA group). At a frequency of 2 Hz and an intensity of 1 mA, electro-acupuncture is performed at the acupoints "Zusanli" and "Kunlun" on both sides for 15 minutes, and then performed at a frequency of 2 mA for 15 minutes, once a day, total 7 doses. Treatment was given. Observe the changes in insulin sensitivity index (ISI) and fasting plasma glucose (FPG) levels of rats fed with high fat and high glucose for 0, 5 and 0, 5, and 7 weeks; changes in paw withdrawal threshold (PWT) are used to detect high The paw withdrawal threshold (PWT) of fat and high-fat rats was measured by electroacupuncture at 0, 5, 7 and 3, 5, and 7 days of sugar intake. Immunofluorescence is used to determine the expression of L5DRGP2X3 receptor. Experiment 2: Rats successfully modeled by DNP were divided into electroacupuncture group (EA + vehicle group) and P2X3 agonist group (EA + αβ-meATP group). Electroacupuncture intervention is the same as above. Before each electric puncture, αβ-meATP (0.6μmol/L, 100μL) was injected under the toes of rats in the EA +αβ-meATP group. Rats in the EA + vehicle group were injected with the same dose of PBS buffer, and other interventions were the same. Detect mechanical pain threshold.

  Result: ①Compared with the control group, after 5 weeks of high-fat and high-sugar in the model group, ISI was significantly reduced (P \u003cu\→ u0.01c0.01), while FPG showed high-fat and high-sugar. After 7 weeks of administration, there was a significant increase (P \u003cu\→ u0c0.01), indicating that the type 2 diabetes model was successfully established (modeling success rate 69.04%). Compared with the model group, the bilateral PWT of rats in the low-frequency electroacupuncture group increased significantly at each time point after treatment (P\u003c0.01); compared with the electroacupuncture group, the bilateral PWT of the P2X3 agonist group Significantly reduced (P\u003c0.01). ③The immunofluorescence results showed that the expression of L5DRGP2X3 positive cells in the model group was significantly higher than that in the control group (P\u003c0.01). The expression of L5DRGP2X3 positive cells was significantly reduced (P\u003c0.01).

  Conclusion: Low-frequency electroacupuncture can effectively improve type 2 DNP by down-regulating the L5DRGP2X3 receptor.