Angiography with radiolabeled red blood cells (RBCs) plays an important role in diagnosis and prognosis in vascular diseases. Both in vitro and in vivo methods have been developed for ^99mTc-labeling of RBCs. However, these methods are complicated and lack reproducibility. Therefore, it is highly desirable to develop an alternative method for routine ^99mTc-labeling of RBCs. In this report, we present a novel approach for ^99mTc-labeling of RBCs. We prepared a new ^99mTc(III) radiotracer [^99mTcCl(CDO)(CDOH)₂B-4AS] (^99mTc-4ASboroxime: 4AS-B(OH)₂ = 4-aminosulfonylphenyl)boronic acid, and CDOH₂ = cyclohexanedione dioxime) in >95% radiochemical purity. Imaging and biodistribution studies were performed in Sprague–Dawley (SD) rats. It was found that the blood radioactivity was ∼6.0%ID/g (∼90% injected dose for 200–225 g SD rats) for ^99mTc-4ASboroxime with low uptake in the myocardium, kidneys, liver, lungs, and muscle, most likely due to lack of leakage of ^99mTc-labeled RBCs from the intravascular space. The blood radioactivity was almost unchanged over the 2 h period, suggesting that the binding of ^99mTc-4ASboroxime to blood components (cells, proteins, and plasma) is stable. The results from γ-counting of the isolated blood components showed that ^99mTc-4ASboroxime had >95% of blood radioactivity binding to RBCs, ∼1% to albumin, and ∼3% remaining free in blood plasma, demonstrating its RBC-specificity. The results from imaging studies in SD rats indicated that ^99mTc-4ASboroxime is predominantly distributed in the blood pool. Main blood vessels were well delineated in the head/neck and abdominal regions. This statement was further substantiated by the results from imaging studies in pigs. ^99mTc-4ASboroxime is an excellent blood pool agent with the potential for diagnosis and prognosis of vascular diseases.

中文翻译：

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^99m Tc标记红细胞的新方法：^99m Tc-4SAboroxime作为血池显像剂的评估

具有放射性标记的红细胞（RBC）的血管造影在血管疾病的诊断和预后中起着重要作用。无论在体外和体内的方法已经被开发用于^99米红细胞锝标记。但是，这些方法复杂且缺乏可重复性。因此，非常需要开发一种常规的RBC的^99m Tc标记的替代方法。在这份报告中，我们提出了一种新的方法，用于RBC的^99m Tc标记。我们准备了一个新的^99m Tc（III）放射性示踪剂[ ^99m TcCl（CDO）（CDOH）₂ B-4AS]（^99m Tc-4ASboroxime：4AS-B（OH）₂＝ 4-氨基磺酰基苯基）硼酸，和CDOH ₂＝环己二酮二肟），其放射化学纯度＞ 95％。在Sprague-Dawley（SD）大鼠中进行了成像和生物分布研究。发现对于^99m Tc-4AS硼^肟，血液放射活性为〜6.0 ％ID / g（200-225 g SD大鼠为〜90％注射剂量），在心肌，肾脏，肝，肺和肌肉中的吸收率较低。可能是由于缺乏^99m Tc标记的RBC从血管内腔漏出。血液放射性在2小时内几乎没有变化，这表明^99m Tc-4ASboroxime与血液成分（细胞，蛋白质和血浆）的结合是稳定的。分离出的血液成分的γ计数结果表明^99mTc-4ASboroxime具有> 95％的血液放射性与RBC结合，〜1％的白蛋白结合和〜3％的血浆游离自由度，证明了其RBC特异性。SD大鼠的影像学研究结果表明，^99m Tc-4ASboroxime主要分布在血池中。主血管在头/颈部和腹部区域被很好地描绘出来。猪的影像学研究结果进一步证实了这一说法。^99m Tc-4ASboroxime是一种出色的血库药物，具有诊断和预后血管疾病的潜力。