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磷酸二酯酶9型抑制剂PF-04449613对大鼠心脏正性肌力作用及其机理

朱晓佳¹, 王羽维¹, 张文慧¹, 高丽¹, 肖钰洁¹, 高倩雯¹, 王荣荣¹, 陈龙^1,2,*

¹南京中医药大学药学院-江苏省中药药效与安全性评价重点实验室，南京 210023；²泰州中国医药城中医药研究院，泰州 225300

摘要

本文旨在研究磷酸二酯酶9型抑制剂PF-04449613对大鼠心脏正性肌力作用及其机理。采用在体双压力-容积环及离体心脏收缩力技术分析其对成年健康大鼠心脏正性肌力的作用特点；运用大鼠心肌细胞钙释放技术分析其作用机理。双压力-容积环实验表明：PF-04449613 (5.5 mg/kg)显著增加大鼠搏出功、心输出量、每博输出量、收缩末期压力及射血分数(P < 0.05)，降低收缩末期容积、舒张末期容积及舒张末期压力(P < 0.05)。PF-04449613对外周动脉血压的作用表现为增加收缩压、降低舒张压及血管阻力(P < 0.05)。大鼠离体心脏灌流实验表明，PF-04449613浓度依赖性地增加离体大鼠左心室发展压(P < 0.05)。以Fluo-4 AM为钙离子荧光指示剂的钙释放结果表明，PF-04449613 (5 μmol/L)显著增强肌浆网钙泵(sarcoplasmic reticulum Ca²⁺-ATPase-2a, SERCA2a)介导的钙释放下降相的快成分，显著增加大鼠心肌细胞钙释放幅值(P < 0.05)。PF-04449613 (5 μmol/L)降低肌浆网钙泄漏率(P < 0.05)。以上结果提示，PF-04449613通过增加SERCA2a活性发挥其对大鼠心脏正性肌力作用。

关键词： 磷酸二酯酶9型; 心室压力-容积环; 钙释放; 肌浆网钙泵

分类号：R969.4

Positive inotropic effect of phosphodiesterase type 9 inhibitor PF-04449613 in rats and its underlying mechanism

ZHU Xiao-Jia¹, WANG Yu-Wei¹, ZHANG Wen-Hui¹, GAO Li¹, XIAO Yu-Jie¹, GAO Qian-Wen¹, WANG Rong-Rong¹, CHEN Long^1,2,*

¹Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China；²Institute of Chinese Medicine of Taizhou China Medical City, Taizhou 225300, China

Abstract

This study aimed to explore the positive inotropic effect of phosphodiesterase type 9 (PDE9) inhibitor PF-04449613 in rats and its cellular and molecular mechanisms. The heart pressure-volume loop (P-V loop) analysis was used to detect the effects of PF-04449613 on rat left ventricular pressure-volume relationship, aortic pressures and peripheral vessel resistance in healthy rats. The Langendorff perfusion of isolated rat heart was used to explore the effects of PF-04449613 on heart contractility. The cardiomyocyte sarcoplasmic reticulum (SR) Ca²⁺ transients induced by field stimulation and caffeine were used to analyze the mechanism underlying the effect of PF-04449613 using Fluo-4 AM as a Ca²⁺ indicator. The results indicated as follows: (1) PF-04449613 (5.5 mg/kg, ip) significantly increased the stroke work, cardiac output, stroke volume, end-systolic pressure and ejection fraction (P < 0.05), and decreased the end-systolic volume, end-diastolic volume and end-diastolic pressure (P < 0.05). Meanwhile, the systolic blood pressure was increased and diastolic blood pressure and arterial elastance were decreased after PF-04449613 treatment (P < 0.05). (2) PF-04449613 (0.001, 0.01, 0.1, 1 μmol/L) significantly increased the left ventricular developed pressure (LVDP) in a concentration-dependent manner in vitro (P < 0.05). (3) PF-04449613 (5 μmol/L) significantly increased the amplitude of SR Ca²⁺ transients mediated by facilitating sarcoplasmic reticulum Ca²⁺-ATPase-2a (SERCA2a) (P < 0.05). (4) PF-04449613 (5 μmol/L) decreased the SR Ca2+ leak rate via ryanodine receptor 2 (RyR2) (P < 0.05). In conclusion, PF-04449613 exerted positive inotropic effect both in vivo and in vitro by enhancing SERCA2a activity.

Key words: phosphodiesterase type 9; ventricular pressure-volume loop; Ca2+ transient; SERCA2a

收稿日期：2020-05-31　　录用日期：2021-01-25

通讯作者：陈龙　　E-mail: longchen@njucm.edu.cn

DOI: 10.13294/j.aps.2021.0010

引用本文：

朱晓佳, 王羽维, 张文慧, 高丽, 肖钰洁, 高倩雯, 王荣荣, 陈龙. 磷酸二酯酶9型抑制剂PF-04449613对大鼠心脏正性肌力作用及其机理[J]. 生理学报 2021; 73 (2): 275-285.

ZHU Xiao-Jia, WANG Yu-Wei, ZHANG Wen-Hui, GAO Li, XIAO Yu-Jie, GAO Qian-Wen, WANG Rong-Rong, CHEN Long. Positive inotropic effect of phosphodiesterase type 9 inhibitor PF-04449613 in rats and its underlying mechanism. Acta Physiol Sin 2021; 73 (2): 275-285 (in Chinese with English abstract).