Cardiac energetics alteration in a chronic hypoxia rat model: A non-invasive in vivo³¹P magnetic resonance spectroscopy study

Article type: Research Article

Authors: Yuan, Xiaohan^{a; b; 1} | Zhu, Xiaomei^{b; 1} | Chen, Yang^b | Liu, Wangyan^b | Qian, Wen^b | Xu, Yi^{b; *} | Zhu, Yinsu^{b; *}

Affiliations: [a] Department of Ultrasuond, The Affiliated Huaian No. 1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu, China | [b] Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China

Correspondence: [*] Corresponding authors: Yinsu Zhu and Yi Xu, Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, China. Tel.: +8613675186571 (YZ); Fax: +862583724440 (YZ); E-mails: [email protected] (YZ) and [email protected] (YX); ORCID iD: 0000-0001-9279-8192 (YZ)

Note: [1] Dr. Xiaohan Yuan and Xiaomei Zhu contributed equally to this work.

Abstract: BACKGROUND:Energetics alteration plays a crucial role in the myocardial injury process in chronic hypoxia diseases (CHD). 31P magnetic resonance spectroscopy (MRS) can investigate alterations in cardiac energetics in vivo. OBJECTIVE:To characterize the potential value of 31P MRS in evaluating cardiac energetics alteration of chronic hypoxic rats (CHRs). METHODS:Twenty-four CHRs were induced by SU5416 combined with hypoxia and divided into four groups according to the modeling time of one, two, three and five weeks, respectively. Control group also contains six rats. 31P MRS was performed weekly and the ratio of concentrations of phosphocreatine (PCr) to adenosine triphosphate (ATP) (PCr/ATP) was obtained. In addition, the cardiac structure index and systolic function parameters, including the right ventricular ejection fraction (RVEF), right ventricular end-diastolic volume index (RVEDVi), right ventricular end-systolic volume index (RVESVi), and the left ventricular function parameters, were measured. RESULTS:Decreased resting cardiac PCr/ATP ratio in CHRs was observed at the first week, compared to the control group (2.90±0.35 vs. 3.31±0.45, p = 0.045), while the RVEF, RVEDVi, and RVESVi decreased at the second week (p < 0.05). The PCr/ATP ratio displayed a significant correlation with RVEF (r = 0.605, p = 0.001), RVEDVi, and RVESVi (r = –0.661, r = –0.703; p < 0.001). CONCLUSIONS:31P MRS can easily detect the cardiac energetics alteration in a CHR model before the onset of ventricular dysfunction. The decreased PCr/ATP ratio likely reveales myocardial injury and cardiac dysfunction.

Keywords: ³¹P magnetic resonance spectroscopy (MRS), cardiac energetics, myocardial injury, chronic hypoxia, rat model

DOI: 10.3233/XST-210985

Journal: Journal of X-Ray Science and Technology, vol. 30, no. 1, pp. 165-175, 2022