Department of Imaging, CHU of Poitiers, Poitiers; Inserm, Tours cedex, France.
Ultrasound Med Biol. 2010 Jan;36(1):51-7. doi: 10.1016/j.ultrasmedbio.2009.06.1103.
The aim of this study was to evaluate the thrombolytic effect of focused transparietal ultrasound in combination with a specific contrast agent (microbubbles) in acute cerebral ischemia. Acute cerebral ischemia was induced in 10 rats by intra-arterial clots injection. Five rats (group 1) were treated with a combination of transparietal ultrasound (probe 2 MHz, acoustic power 500 mW/cm(2)) and intravenous injection of 0.6 mL of the ultrasound contrast agent (UCA) sulfur hexafluoride. Five rats (group 2) were treated by fibrinolytic intravenous infusion (recombinant tissue plasminogen activator). Cerebral cellular energy production was determined by measuring the cellular phosphorylation using phosphorus magnetic spectroscopy before and during ischemia induction and after treatment. Measures were performed on a dedicated 2.35T magnet. The ratio phosphocreatine (P(Cr)) on inorganic phosphate (P(i)), P(Cr)/P(i), estimation of the oxidative phosphorylation metabolism and the intracellular pH (pHi) were measured in the two groups. Compared with the ischemia induction period, both treatments were associated with an increase of P(Cr)/P(i) and pHi values, respectively, +80% and +100% in group 1 (p=0.07) and +100% and +80% in group 2 (p=0.04). There was no significant difference between the two groups for the response treatment. To conclude, treatment with intravenous fibrinolytic infusion and treatment with focused ultrasound in combination with UCA seems to be equally effective in treating acute cerebral ischemia in rats. (E-mail: j.p.tasu@chu-poitiers.fr).
本研究旨在评估透壁超声联合特定对比剂（微泡）在急性脑缺血中的溶栓效果。通过动脉内血栓注射诱导 10 只大鼠发生急性脑缺血。5 只大鼠（第 1 组）接受透壁超声（探头 2 MHz，声能 500 mW/cm²）联合静脉注射 0.6 mL 超声对比剂（六氟化硫）治疗。5 只大鼠（第 2 组）接受纤维蛋白溶解静脉输注（重组组织型纤溶酶原激活剂）治疗。在缺血诱导前、诱导期间和治疗后，通过磷磁共振谱测量细胞磷酸化来确定细胞能量产生。测量在专用 2.35T 磁体上进行。在两组中测量磷酸肌酸（P(Cr)）与无机磷（P(i)）的比值（P(Cr)/P(i)）、氧化磷酸化代谢的估计值和细胞内 pH 值（pHi）。与缺血诱导期相比，两种治疗方法均使 P(Cr)/P(i)和 pHi 值分别增加 80%和 100%（第 1 组，p=0.07）和 100%和 80%（第 2 组，p=0.04）。两组之间的治疗反应没有显著差异。总之，静脉内纤维蛋白溶解输注治疗和联合超声对比剂的聚焦超声治疗在治疗大鼠急性脑缺血方面似乎同样有效。（电子邮件：j.p.tasu@chu-poitiers.fr）。
