Metabolic imaging of acute and chronic infarction in the perfused rat heart using hyperpolarised [1-13C] pyruvate
Metabolic imaging of acute and chronic infarction in the perfused rat heart using hyperpolarised [1-13C] pyruvate
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DOI：
10.1002/nbm.2972
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发表时间：
2013-11-01
影响因子：
2.9
通讯作者：
Tyler, Damian J.
中科院分区：
文献类型：
--
作者：
Ball, Daniel R.;Cruickshank, Rachel;Tyler, Damian J.
超极化的C-13MRI可以用来生成活体心脏的代谢图像。然而，还没有在隔离的灌流心脏中进行类似的研究。因此，本研究的目的是建立一种建立大鼠心脏灌流的C-13代谢物图谱的方法，并在急性和慢性心肌梗死的研究中展示该技术。雄性Wistar大鼠心脏在左冠状动脉前降支(LAD)阻断前后分离、灌流并成像，建立急性梗死组。此外，在活体条件下，LAD冠脉闭塞的心脏会产生慢性梗死组。四周后，心脏被切除、灌流和成像，以生成注入的丙酮酸及其代谢物乳酸和碳酸氢盐的代谢图。首次通过心肌灌注成像和P-31MRS分别评价心肌灌注和能量学。无论是急性心肌梗死还是慢性心肌梗死，梗死区的血流灌注量均减少，表现为超极化的丙酮酸图像中的Gd流入减少和信号强度降低。在急性梗死区，乳酸(升高)和碳酸氢盐(降低)信号比率有显著变化。在慢性梗死区，碳酸氢盐和乳酸信号均显著减少。P-31衍生的能量学显示对照组和慢性梗死组的心脏显著减少。对照组和急性和慢性心肌梗死患者之间的收缩功能也显著降低。总而言之，我们已经证明，超极化丙酮酸可以检测到急性和慢性脑梗塞后大鼠心脏灌注量的减少。乳酸和碳酸氢盐比率的变化表明急性梗死区无氧代谢增强，而慢性梗死区则未观察到。因此，这项研究成功地展示了一种新的成像方法来评估离体灌流大鼠心脏代谢的变化。(C)2013年提交人。约翰·威利父子有限公司出版的生物医学中的核磁共振
Hyperpolarised C-13 MRI can be used to generate metabolic images of the heart in vivo. However, there have been no similar studies performed in the isolated perfused heart. Therefore, the aim of this study was to develop a method for the creation of C-13 metabolite maps of the perfused rat heart and to demonstrate the technique in a study of acute and chronic myocardial infarction. Male Wistar rat hearts were isolated, perfused and imaged before and after occlusion of the left anterior descending (LAD) coronary artery, creating an acute infarct group. In addition, a chronic infarct group was generated from hearts which had their LAD coronary artery occluded in vivo. Four weeks later, hearts were excised, perfused and imaged to generate metabolic maps of infused pyruvate and its metabolites lactate and bicarbonate. Myocardial perfusion and energetics were assessed by first-pass perfusion imaging and P-31 MRS, respectively. In both acute and chronically infarcted hearts, perfusion was reduced to the infarct region, as revealed by reduced gadolinium influx and lower signal intensity in the hyperpolarised pyruvate images. In the acute infarct region, there were significant alterations in the lactate (increased) and bicarbonate (decreased) signal ratios. In the chronically infarcted region, there was a significant reduction in both bicarbonate and lactate signals. P-31-derived energetics revealed a significant decrease between control and chronic infarcted hearts. Significant decreases in contractile function between control and both acute and chronic infracted hearts were also seen. In conclusion, we have demonstrated that hyperpolarised pyruvate can detect reduced perfusion in the rat heart following both acute and chronic infarction. Changes in lactate and bicarbonate ratios indicate increased anaerobic metabolism in the acute infarct, which is not observed in the chronic infarct. Thus, this study has successfully demonstrated a novel imaging approach to assess altered metabolism in the isolated perfused rat heart. (c) 2013 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd