磷酸二酯酶8型抑制剂PF-04957325对大鼠心脏正性肌力作用及其机理  

The positive inotropic effect of phosphodiesterase type 8 inhibitor of PF-04957325 in rats and its underlying mechanism

作　　者：肖钰洁 高倩雯 王羽维 朱晓佳 陈可塑 刘福明[3] 王荣荣 陈龙 XIAO Yu-Jie;GAO Qian-wen;WANG Yu-wei;ZHU Xiao-jia;CHEN Ke-su;LIU Fu-ming;WANG Rong-rong;CHEN Long(Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica,School of Pharmacy,Nanjing University of Chinese Medicine,Nanjing 210023,China;Wound Care Centre,Dept of Outpatient,Jinling Hospital,the Affiliated Hospital of Medical School of Nanjing University,Nanjing 210000,China;First Affiliated Hospital,Nanjing University of Chinese Medicine,Nanjing 210093,China;Institute of Chinese Medicine of Taizhou China Medical City,Taizhou Jiangsu 225300,China)

机构地区：[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,江苏南京210023 [2]南京大学医学院附属医院,金陵医院门诊部伤口护理中心,江苏南京210000 [3]南京中医药大学附属医院,江苏省中医院,江苏南京210029 [4]泰州中国医药城中医药研究院,江苏泰州225300

出　　处：《中国药理学通报》2021年第9期1264-1270,共7页Chinese Pharmacological Bulletin

基　　金：江苏省“六大人才高峰”项目(No TD-SWYY-069);江苏省科技计划社会发展-面上项目(No SEB2020740365)。

摘　　要：目的研究磷酸二酯酶8型抑制剂PF-04957325对大鼠心脏正性肌力作用及其机理。方法采用在体大鼠左心室双压力-容积环(P-V loop)及离体心脏技术分析心血管血流动力学;场刺法分析心肌细胞钙释放动力学;Western blot法分析肌浆网受磷蛋白(PLB)及兰尼碱受体(RyR2)磷酸化水平。结果在体实验表现,颈静脉给予PF-04957325(0.5 mg·kg^(-1))明显增加左心室搏出功、心输出量、每搏输出量、收缩末期压、心率、射血分数、动脉收缩压;降低收缩末期的容积、舒张末期的容积、动脉舒张压、外周血管阻抗。离体心脏实验表明,在pacing及non-pacing条件下,PF-04957325增加离体大鼠左心室收缩力。机理研究表明,PF-04957325(1μmol·L^(-1))增加心肌细胞钙释放幅值、肌浆网钙泵活性及肌浆网受磷蛋白磷酸化,对兰尼碱受体磷酸化水平无作用。结论磷酸二酯酶8型抑制剂PF-04957325通过增加肌浆网受磷蛋白磷酸化而增加钙泵活性,实现收缩力增加。Aim To investigate the inotropic effect of PF-04957325,a phosphodiesterase type 8 inhibitor,in normal rats and its underlying molecular mechanism.Methods The techniques of in vivo rat left ventricular pressure-volume loop(P-V loop)and isolated perfusion rat heart were used to analyze the hemodynamics and positive inotropic effect of rat hearts.The Ca 2+transient induced by field stimulation was used to analyze the hemodynamics of sarcoplasmic reticulum(SR)Ca 2+uptaking.Western blot was used to analyze the phosphorylation levels of SR phospolamban(PLB)and ryanodine receptor type 2(RyR2).Results The P-V loop experiment indicated that PF-04957325(0.5 mg·kg^(-1))increased the rat left ventricular stroke work,cardiac output,stroke volume,end-systolic pressure,heart rate,ejection fraction and arterial systolic pressure and decreased the end-systolic volume,end-diastolic pressure,arterial diastolic pressure and peripheral vessel resistance.The rat isolated heart experiment demonstrated that PF-04957325 enhanced the left ventricular developed pressures and peak rate of rise of left ventricular pressure(+d p/d t max)in a concentration-dependent manner in both of pacing and non-pacing modes.Also,PF-04957325(1μmol·L^(-1))increased the amplitude of SR Ca 2+transient and facilitated the activity of SR Ca 2+ATPase 2a(SERCA2a).Moreover,PF-04957325(1μmol·L^(-1))increased the phosphorylation levels of phospholamban at serine-16 and threonine-17.Conclusions PF-04957325,a phosphodiesterase type 8 inhibitor,exerts the positive inotropic effect by increasing phospholamban phosphorylation levels both at serine-16 and threonine-17.The phosphodiesterase type 8 may serve as a target for developing the drugs for treating the heart failure in clinical settings.

关 键 词：磷酸二酯酶8型 心室压力-容积环 钙释放 肌浆网钙泵 受磷蛋白 兰尼碱受体 

分 类 号：R-332[医药卫生] R322.11