[Impacts of electroacupuncture on ubiquitin-proteasome system in rats with Parkinson's disease]

To explore action mechanism of electroacupuncture (EA) on treatment and prevention of Parkinson's disease (PD).

Fifty clean-grade SD rats were randomly divided into a normal group, a control group, a model group, a pretreatment group and a treatment group, ten rats in each one. The PD model was established by subcutaneous injection of rotenone in neck-back skin (2 mg/kg, dissolved in sun-flower oil, 2 mg/mL in density). The equal-volume sun-flower oil that didn't include rotenone was applied in the control group at the same area as the model group. EA was applied in the treatment group at "Fengfu" (GV 16) and "Taichong" (LR 3) with interrupted wave, 2 Hz in frequency, 1 mA in density, for 20 min. The treatment was given once day for conti-nuous 28 days. Rats in the pretreatment group received the same EA as the treatment group for 7 days, and then put into model establishment. After the model establishment, the rats received no treatment and were sacrificed after 28 days. No EA was given in the normal group, model group and control group. The ethology changes were observed and scored. The expression of Parkin, ubiquitin C terminal hydrolase-L1 (UCH-L1) and ubiquitin activating enzyme-1 (UBE1) in substantia nigra was tested by Western-blot method. The positive cell numbers of alpha-synuclein, ubiquitin (UB) and tyrosine hydroxylase (TH) in substantia nigra was tested by immunohistochemical method.

There were abnormal ethology manifestation such as yellow and coarse hair, arched back, weaken behavior of resisting arrest and slow movement, which was more relieved in the treatment group and pretreatment group. Compared with normal group and control group, the expression of Parkin, UCH-L1, UBE1, UB, TH in the model group was obviously decreased while alpha-synuclein was obviously increased (all P<0.01). After EA or pretreatment, the expression of Parkin, UCH-L1, UBE1, UB, TH in the treatment group and pretreatment group was higher than that in the model group while expression of alpha-synuclein in the treatment group and pretreatment group was lower than that in the model group (all P<0.01).

EA or pretreatment could not only have protective effect for rats with PD, but also increase function of ubiquitin-proteasome system, indicating action mechanism of EA on treatment and prevention of PD may be related with ubiquitin-proteasome system.