EA effects on OP

Study of the effects and mechanisms of electric stimulate acupoints induced bone mineral density changes.

Osteoporosis is a progressive bone disorder characterized by low bone mass and microarchitecture deterioration of bone tissue, leading to increased bone fragility and susceptibility to fracture. Electrical stimulation for bone repair has been used for three decades and was approved by the Food and Drug Administration (FDA) for pseudarthrosis and bone nonunion. Mechanical or electrical stimuli of relative low amplitude and high frequency can influence bone formation and resorption in vitro and in vivo, suggesting that these modalities can be used clinically to inhibit or reverse osteopenia.

We hypothesized that electric stimulation for acupoints can induce bone mineral density (BMD) change in ovariectomized (OVX) rats. Twenty-four 6-week old SD female rats (BioLASCO Taiwan Co., Ltd.) weighing 180-220 g were used in this study. The rats were randomly divided into a control group (n=8), a sham group (n=8) and an electroacupuncture(EA) group (n=8). The acupuncture group were given acupuncture bilaterally at ST36 and SP6, 15mins per time, five times a week for 4 weeks (total 20 times), under isoflurane anesthesia (in flow of oxygen and nitrous oxide mixture; 3% for induction and 1.5% for maintenance). The positive electrode was connected to ST36, and the negative electrode to SP6. Electrical stimulation were provided by a pulse stimulator (Trio 300, Ito Co., Japan), which produced a biphasic square wave with the following characteristics: 2 Hz frequency, 2 mA duration pulses. The current intensity were adjusted until localized muscle contractions were observed.

Bone morphogenetic protein (BMP) plays important roles in osteoblastic differentiation and bone formation. Therefore, therapies involved in BMP activation are good ways for the development of anti-osteoporosis treatments. In this study, EA was shown to enhance serum alkaline phosphatase (ALP) and BMP-2 activity of OVX rats. EA also increased the bone volume of secondary spongiosa in tibia.
Taken together, our results provided the evidence that EA could increase BMP-2 and enhance bone formation in OVX rats.

【撰寫/臻品中醫診所╱吳啟銘醫師】