Research on specification conditions of the ultrasonic stimulation which promote the regeneration of the cartilage using intracellular signaling analysis

本研究的目的是阐明改变低强度脉冲超声（LIPUS）的重复频率（RF）和强度（Po）对培养的牛关节软骨细胞的影响。从牛的跖趾关节获得软骨细胞并进行培养。为了分析RF和Po的影响，LIPUS暴露于50、500、1000 Hz的RF和75、150、300 mW/cm ^2的强度下|SATP。在培养24小时后，每天对软骨细胞施加20分钟的LIPUS刺激。在培养后7天的时间，通过实时RT-PCR评估聚集蛋白聚糖（AGC）、II型胶原（COL 2）和IX型胶原（COL 9）的mRNA水平。在强度为150 mW/cm^2的条件下|SATP、500 Hz射频使AGC mRNA的表达增加了对照组的168%（p<0.05）。50 Hz射频条件下COL 9 mRNA表达量增加158%（p<0.01）。将RF设置为1000 Hz并改变强度，Po-300 mW/cm ^2使COL 9的mRNA表达增加对照的147%（p<0.05）。结果提示，改变LIPUS的RF可影响细胞内各蛋白质mRNA的表达。此外，LIPUS强度和RF的变化可能会影响软骨细胞在培养过程中产生的某些产物。

The purpose of this study is to clarify the influence of changing repetition frequency(RF) and intensity(Po) of Low-Intensity Pulsed Ultrasound(LIPUS) for cultured bovine articular chondrocytes. Chondrocytes were obtained from the metatarso-phalangeal joints of bovine and were cultured. To analyze the effect of RF and Po, LIPUS was exposed at RF of 50, 500, 1000Hz and at intensity of 75, 150, 300 mW/cm^2| SATP. LIPUS stimulation for 20 minutes every day was applied to chondrocytes after 24 hours in culture. At the time of 7 days after culture, mRNA levels of Aggrecan(AGC), Type II collagen(COL2), and Type IX collagen(COL9) were evaluated by Real-time RT-PCR. In intensity, condition of 150 mW/cm^2| SATP, the RF of 500Hz increased expression of mRNA for AGC by 168% of control(p<0.05). The condition of RF of 50Hz increased expression of mRNA for COL9 by 158% of control(p<0.01). RF was set to 1000 Hz and intensity was changed, Po-300 mW/cm^2 increased expression of mRNA for COL9 by 147% of control(p<0.05). These results suggested that changing of RF of LIPUS may affect expression of each mRNA of protein in the cell. In addition, the changing of intensity and RF of LIPUS may influence to some products produced by chondrocytes during culture.