Jing Xiang-xiang, Wang Zhi-gang, Ran Hai-tao, Li Ling, Wu Xing, Li Xiao-dong, Peng Xiao-qiong, Yang Chun-jiang, Li Xing-sheng, Zhang Qun-xia
Department of Ultrasonography, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, PR China.
Clin Imaging. 2008 May-Jun;32(3):178-82. doi: 10.1016/j.clinimag.2008.03.001.
The objective of this study was to noninvasively evaluate the severity of renal ischemia-reperfusion (I-R) injury in rabbits with microbubbles targeted to activated neutrophils [phosphatidylserine-conjugated surfactant perfluoropropane-filled microbubbles (SPMB-PS)].
Microbubbles targeted to activated neutrophils (SPMB-PS) were prepared by conjugating phosphatidylserine (PS) to self-assembling surfactant perfluoropropane-filled microbubbles (SPMB). Flow cytometry was performed to assess the presence of PS in SPMB. A renal I-R injury model was established in 18 rabbits for contrast-enhanced ultrasonography. Examination of ultrasonography with SPMB-PS and SPMB was performed on 12 rabbits before and after I-R injury. The time-intensity curve (TIC) was generated from a selected region of interest. Another six rabbits with renal I-R injury underwent contrast-enhanced ultrasonography for 15 min after intravenous injection of SPMB-PS. The renal tissues were immediately excised for immunohistochemical staining and myeloperoxidase (MPO) activity analysis. The correlation between MPO activity and echo intensity (VI) was analyzed.
Flow cytometry demonstrated that PS was located on the surface of SPMB. TIC showed that the time at which the maximum VI was reached and the time needed for the microbubbles to wash out were the same in the normal kidneys injected with SPMB-PS or SPMB, while there was an obvious delay in emptying time with SPMB-PS compared with SPMB after I-R injury. Fifteen minutes after the injection of SPMB-PS and SPMB, VI was not remarkably different (P>.05) in the normal kidneys, while it was significantly higher (P<.01) in the I-R-injured kidneys. There was a strong correlation between MPO activity and VI 15 min after the injection of SPMB-PS (r=.933, P<.01). Immunohistochemistry showed that most of the inflammatory cells in the I-R-injured kidneys were neutrophils.
A delayed emptying phenomenon was observed during contrast-enhanced ultrasonography in the I-R-injured kidneys, with SPMB-PS targeted to activated neutrophils. Therefore, contrast-enhanced ultrasonography with SPMB-PS may noninvasively evaluate the severity of ischemia-reperfusion injury to the kidneys.
本研究的目的是使用靶向活化中性粒细胞的微泡[磷脂酰丝氨酸共轭表面活性剂全氟丙烷填充微泡（SPMB - PS）]对兔肾缺血再灌注（I - R）损伤的严重程度进行无创评估。
通过将磷脂酰丝氨酸（PS）与自组装表面活性剂全氟丙烷填充微泡（SPMB）共轭制备靶向活化中性粒细胞的微泡（SPMB - PS）。进行流式细胞术以评估SPMB中PS的存在情况。在18只兔中建立肾I - R损伤模型用于超声造影。对12只兔在I - R损伤前后使用SPMB - PS和SPMB进行超声检查。从选定的感兴趣区域生成时间强度曲线（TIC）。另外6只肾I - R损伤的兔在静脉注射SPMB - PS后进行15分钟的超声造影。立即切除肾组织进行免疫组织化学染色和髓过氧化物酶（MPO）活性分析。分析MPO活性与回声强度（VI）之间的相关性。
流式细胞术表明PS位于SPMB表面。TIC显示，在注射SPMB - PS或SPMB的正常肾脏中，达到最大VI的时间和微泡洗脱所需的时间相同，而I - R损伤后与SPMB相比，SPMB - PS的排空时间明显延迟。注射SPMB - PS和SPMB 15分钟后，正常肾脏中的VI无明显差异（P>0.05），而在I - R损伤的肾脏中VI显著更高（P<0.01）。注射SPMB - PS 15分钟后，MPO活性与VI之间存在强相关性（r = 0.933，P<0.01）。免疫组织化学显示，I - R损伤肾脏中的大多数炎性细胞是中性粒细胞。
在I - R损伤的肾脏中，超声造影期间观察到延迟排空现象，使用靶向活化中性粒细胞的SPMB - PS。因此，使用SPMB - PS的超声造影可能无创评估肾脏缺血再灌注损伤的严重程度。
