示踪剂腺苷：一种新型心肌血流标志物。

Lauer Thomas, Loncar Robert, Deussen Andreas

Klinik für Kardiologie, Pneumologie und Angiologie, Heinrich-Heine-Universität, Düsseldorf, Germany.

J Nucl Med. 2003 Apr;44(4):641-8.

UNLABELLED

Local myocardial blood flow measurements are of great importance in experimental and clinical settings. However, a lack of ideal markers is evident. Adenosine is suggested to be a potential candidate because of its high uptake and rapid intracellular sequestration. We specifically tested the hypothesis that the local deposition density of labeled adenosine within the heart reflects local myocardial blood flow.

METHODS

Tracer microspheres, the recognized standard for local blood flow measurements, were injected and compared with simultaneously injected labeled adenosine ((3)H/(14)C) in tracer concentration into the left atrium of anesthetized Beagle dogs (n = 7). Myocardial deposition densities were assessed through beta-scintillation and gamma-counting measurements in samples (100-128 per heart) of an average wet mass of 487 +/- 54 mg. To challenge local myocardial blood flow distribution, alprostadil was infused into the left circumflex artery in 3 experiments. In 2 other experiments, erythro-9-hydroxy-nonyl-adenine (EHNA) was infused to inhibit degradation of injected adenosine to inosine.

RESULTS

Tracer adenosine and microspheres did not exert significant local or systemic hemodynamic effects. Both were almost completely extracted from blood within 2 min and locally retained in the tissue. Deposition densities of tracer microspheres and labeled adenosine correlated closely in each experiment, independently of the respective protocol (control, EHNA, or alprostadil), over a wide range of local myocardial blood flows (0.23-12.9 mL min(-1) g(-1)). The mean correlation coefficient (n = 293) was r = 0.93 (r(2) = 0.86; P < 0.0001), indicating that the deposition density of (3)H-adenosine could explain local blood flow as measured with the tracer microsphere technique with 86% probability.

CONCLUSION

Adenosine appears to be a reliable marker of local blood flow in dog myocardium.

未标记

局部心肌血流量测量在实验和临床环境中具有重要意义。然而，明显缺乏理想的标志物。腺苷因其高摄取率和快速的细胞内隔离而被认为是一个潜在的候选物。我们专门测试了这样一个假设，即心脏内标记腺苷的局部沉积密度反映局部心肌血流量。

方法

将示踪微球（局部血流量测量的公认标准）注入麻醉的比格犬（n = 7）左心房，并与同时注入的标记腺苷（³H/¹⁴C）在示踪剂浓度方面进行比较。通过对平均湿质量为487±54 mg的样本（每个心脏100 - 128个）进行β闪烁和γ计数测量来评估心肌沉积密度。为了挑战局部心肌血流分布，在3个实验中向左回旋支动脉注入前列地尔。在另外2个实验中，注入erythro - 9 - hydroxy - nonyl - adenine（EHNA）以抑制注入的腺苷降解为肌苷。

结果

示踪腺苷和微球未产生显著的局部或全身血流动力学效应。两者在2分钟内几乎完全从血液中提取并局部保留在组织中。在每个实验中，示踪微球和标记腺苷的沉积密度密切相关，与各自的方案（对照、EHNA或前列地尔）无关，在广泛的局部心肌血流量范围（0.23 - 12.9 mL min⁻¹ g⁻¹）内。平均相关系数（n = 293）为r = 0.93（r² = 0.86；P < 0.0001），表明³H - 腺苷的沉积密度能够以86%的概率解释用示踪微球技术测量的局部血流量。