聚焦超声单次治疗慢性软组织损伤兔局部肌组织前列腺素E2、pH值以及血浆β-内啡肽的变化

Changes in prostaglandin E2 and pH value in injured muscle tissue and beta-endorphin in plasma after a single treatment of focused ultrasound in rabbits with chronic soft tissue injury

目的:观察兔慢性软组织损伤经聚焦超声单次治疗后局部肌组织的前列腺素E2、pH值以及血浆β-内啡肽的变化,初步探讨聚焦超声治疗慢性软组织损伤的机制。方法:实验于2006-09/2007-08在重庆医科大学医学超声工程研究所实验室完成。①分组:选72只健康家兔,雌雄不拘,随机分为模型组、对照组和超声组3组,各24只;每组又按治疗后观察时间点随机分为30min、3,7d3个时间点,每时间点8只。②干预:制备兔慢性软组织损伤模型。造模完成后第2日,超声组应用H5018型聚焦超声阿是治疗仪给予聚焦超声单次治疗,超声输出为连续式,频率1.8MHz,焦点声强2.25W/cm2,先行固定法治疗20s,间隔5s,再行移动法治疗60s。对照组给予假治疗,模型组不治疗。③评估指标:各组不同时间局部肌组织前列腺素E2含量(ELISA法)与pH值;并选超声组与对照组中的治疗后3d实验兔,分别于治疗前、治疗后5min,24h采耳缘静脉血,放射免疫法检测血浆β-内啡肽水平。结果:72只实验兔均进入结果分析。①局部肌组织前列腺素E2与pH值变化:治疗后30min,超声组前列腺素E2含量低于对照组和模型组(P<0.01),pH值高于对照组和模型组(P<0.01);而治疗后3,7d,3组间前列腺素E2含量及pH值差异均无显著性意义(P>0.05)。②β-内啡肽质量浓度变化:超声组治疗后5min显著高于治疗前(P<0.01),治疗后24h与治疗前差异无显著性意义(P>0.05);对照组中治疗前后各时间点比较差异均无显著性意义(P>0.05)。结论:聚焦超声对慢性软组织损伤的治疗作用可能与损伤部肌组织的前列腺素E2含量降低、pH值升高以及血浆β-内啡肽水平升高有关。

AIM： To observe the changes in the content of prostaglandin E2 （PGE2）, pH value in injured muscle tissue, and β -endorphin （ β - EP） in plasma after a single treatment of focused ultrasound in rabbits with chronic soft tissue injury, and to explore the mechanism of focused ultrasound for the treatment of chronic soft tissue injury. METHODS： The experiment was performed at Institute of Ultrasound Engineering in Medicine, Chongqing Medical University from September 2006 to August 2007. （1）Seventy-two healthy rabbits irrespective of gender were selected and randomized into 3 groups （n =24）： model group, control group and ultrasound group. Each group was subdivided into 3 subgroups according to different time points of observation after treatment （n =8）： 30 minutes, 3 and 7 days. （2）Rabbit models of chronic soft tissue injury were successfully established. On the 2^nd day after modeling, the ultrasound group underwent a single treatment of focused ultrasound with 1.8 MHz, focus intensity of 2.25 W/cm^2, a continuous output wave, and fixed way for 20 seconds, 5 seconds interval, and removal way for 60 seconds. The control group was subjected to sham exposure. No treatment was given to the model group. （3） The contents of PGE2 （ELISA） and pH value in injured muscle tissue were detected. The blood samples were drawn from ear veins of rabbits in the ultrasound group and control group treated for 3 days to test the mass concentrations of β -EP in plasma by radioimmunoassay before, 5 minutes and 24 hours after treatment. RESULTS： All 72 rabbits were included in the final analysis. （1）The content of PGE2 was significantly decreased and pH value was significantly increased in ultrasound group compared with control group and model group 30 minutes after treatment （P 〈 0.01）. The contents of PGE2 and pH value had no difference respectively among three groups 3 and 7 days after treatment （P 〉 0.05）. （2）In ultrasound group, the mass concentration of β-EP was significantly increased at 5 minutes after treatment compared with that before treatment （P 〈 0.01 ）. There was no difference between that before treatment and 24 hours after treatment （P 〉0.05）. The mass concentrations of β -EP had no difference within the control group at each time point （P 〉 0.05）. CONCLUSION： The effects of focused ultrasound on chronic soft tissue injury might be highly correlated with a decrease in PGE2, an increase in pH value in injured muscle tissue, and an increase in plasma β -EP.