OBJECTIVETo explore mechanism of acupuncture for renal interstitial fibrosis (RIF) in hypertension rats.

METHODSTwenty-four 24-week-old male spontaneously hypertensive rats were randomly divided into a model group, a perindopril group and an acupuncture group, eight cases in each one. In the acupuncture group, with rats tied up, electroacupuncture was applied at bilateral "Quchi" (LI 11) and "Zusanli" (ST 36) under mild vibration of needle handle for 20 min, once a day. In the perindopril group, perindopril (0.4 mg/kg) suspension liquid was applied for intragastric administration, once a day. In the model group, rats were tied up for 20 min a day without any treatment. Eight same-age same-race Wistar Kyoto (WKY) rats with normal blood pressure were taken as a control group, which was given with free diet but no treatment. The treatment was reuqired for six weeks. The systolic blood pressure of caudal artery was tested. Kidney morphological structure was observed by HE coloration. Deposition optical density of type I and III collagen in kidney was tested by immunohistochemistry. Expression of transforming growth factor-beta1 (TGF-beta1) mRNA was tested by reverse transcription polymerase chain reaction (RT-PCR) method.

RESULTSCompared with the model group, the blood pressure was significantly decreased in the acupuncture group (P < 0.01), the damage of kidney morphology was minor, positive depositional area of type I and III collagen was obviously decreased (both P < 0.05), and the expression of semi-quantitative analysis of TGF-beta1 mRNA was decreased (P < 0.05), which had similar effect as western medication perindopril.

CONCLUSIONAcupuncture at "Quchi" (LI 11) and "Zusanli" (ST 36) probably intervenes the process of RIF by reducing synthesis of kidney type I , III collagen and restraining expression of TGF-beta1.