摘要
目的探讨有氧运动对老龄小鼠心肌钠尿肽-环磷酸鸟苷(cGMP)-cGMP依赖性蛋白激酶(PKG)信号通路及心肌功能的影响。方法4月龄雄性C57BL/6J小鼠作为青年组,20月龄雄性C57BL/6J小鼠随机分为老龄(aged)组和老龄运动(aged+E)组,每组15只。老龄运动组给予8周的游泳运动处理(60 min/d,每周5次)。采用小动物超声仪计算左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)、左心室收缩末内径(LVESD)和左心室舒张末内径(LVEDD)以评价左心功能;通过检测心肌组织中Caspase-3活性评价心肌凋亡的变化,检测丙二醛(MDA)、超氧化物歧化酶(SOD)及活性氧(ROS)的活性,评估心肌氧化应激;检测血浆及心肌组织中ANP和BNP的含量,评估钠尿肽的含量;检测心肌组织中cGMP活性及PKG蛋白表达,评估cGMP-PKG信号通路。结果与青年组相比,老龄组小鼠心脏功能显著降低(P<0.01),心肌组织Caspase-3、MDA及ROS活性显著增加(P<0.01),SOD活性显著降低(P<0.01),血浆及心肌组织中ANP和BNP含量显著增加(P<0.01),同时cGMP活性及PKG活性显著降低(P<0.01)。与老龄组相比,老龄运动组小鼠心脏功能增加(P<0.05),心肌组织Caspase-3、MDA及ROS活性降低(P<0.05或P<0.01),SOD的活性增加(P<0.05),血浆及心肌组织BNP的含量降低(P<0.05),同时cGMP及PKG活性增加(P<0.05或P<0.01)。结论游泳运动训练可改善老龄小鼠心肌功能,其机制与抑制心肌细胞凋亡Caspase-3的活性和氧化应激、激活BNP-cGMP-PKG信号通路有关。
Objective To investigate the effect of aerobic exercise on cardiac natriuretic peptide-cGMP-PKG signaling pathway and myocardial function in aged mice.Methods Four-month-old male C57BL/6J mice were chosen as young group,and 20-month-old male C57BL/6J mice were divided into aged group(n=15)and aged+exercise group(aged+E,n=15).The mice in aged+E group were given swimming training for 8 weeks(60 min/d,5 times/week).Left ventricular ejection fraction(LVEF),left ventricular short-axis shortening rate(LVFS),left ventricular end-systolic diameter(LVESD),and left ventricular end-diastolic diameter(LVEDD)were determined by small animal ultrasound system.Myocardial apoptosis and myocardial oxidative stress were evaluated by detecting the activities of Caspase-3,malondialdehyde(MDA),superoxide dismutase(SOD)and reactive oxygen species(ROS).The level of natriuretic peptide was evaluated by ANP and BNP contents in plasma and myocardial tissue.The activities of cGMP and PKG were detected to evaluate cGMP-PKG signaling pathway.Results Compared with young group,the cardiac function was significantly decreased in aged group(P<0.01),the activities of Caspase-3,MDA and ROS in myocardial tissue were increased(P<0.01),SOD activity was decreased(P<0.01),the contents of ANP and BNP in plasma and myocardial tissue were increased(P<0.01),and the activities of cGMP and PKG were decreased(P<0.01).Compared with aged group,the cardiac function of mice was significantly increased in aged+E group(P<0.05).Compared with aged group,the activities of Caspase-3,MDA and ROS in myocardial tissue and the content of BNP were decreased(P<0.05 or P<0.01),while the activities of SOD,cGMP and PKG in plasma and myocardial tissue were increased in aged+E group(P<0.05 or P<0.01).Conclusion Swimming exercise can improve the myocardial function in aged mice,which is related to the inhibition of apoptosis and oxidative stress,and the activation of BNP-cGMP-PKG signaling pathway.
作者
常盼
于军
王建榜
张静
陈伟国
刘建荣
CHANG Pan;YU Jun;WANG Jianbang;ZHANG Jing;CHEN Weiguo;LIU Jianrong(Central Laboratory of Second Affiliated Hospital of Xi’an Medical University,Xi’an 710038,China;Shaanxi Provincial Clinical Medical Research Center of Cardiovascular Diseases)
出处
《山西医科大学学报》
CAS
2022年第11期1418-1423,共6页
Journal of Shanxi Medical University
基金
国家自然科学基金资助项目(81870172)
陕西省教育厅专项科学研究项目(21JK0897)
陕西省科技厅自然基础研究项目(重点项目)(2021JQ-787)
西安市科技局医学研究项目(20YXYJ003(3))。
