Radiology Department, University of Texas Health Science Center, San Antonio, TX, USA.
University of Wyoming, Laramie, WY, USA.
J Physiol. 2018 Nov;596(21):5083-5098. doi: 10.1113/JP276338. Epub 2018 Sep 19.
Life course changes in cardiovascular function in a non-human primate have been comprehensively characterized. Age-related declines in normalized left ventricular stroke volume and cardiac output were found with corresponding decreases in biventricular ejection fractions and filling rates. There were age-related decreases in male and female baboon normalized left ventricular myocardial mass index, which declined at similar rates. Systolic functional declines in right ventricular function were observed with age, similar to the left ventricle. Sex differences were found in the rates and directions of right ventricular volume changes along with decreased end-systolic right ventricular sphericity. The results validate the baboon as an appropriate model for translational studies of cardiovascular functional decline with ageing.
Previous studies reported cardiac function declines with ageing. This study determined changes in biventricular cardiac function in a well-characterized baboon model. Cardiac magnetic resonance imaging measured key biventricular parameters in 47 baboons (22 female, age 4-23 years). ANCOVA assessed sex and age changes with P < 0.05 deemed significant. Stroke volume, cardiac output and other cardiac functional parameters were normalized to body surface area. There were similar, age-related rates of decrease in male (M) and female (F) normalized left ventricular (LV) myocardial mass index (M: -1.2 g m year , F: -0.9 g m year ). LV ejection fraction declined at -0.96% year (r = -0.43, P = 0.002) and right ventricular (RV) ejection fraction decreased at -1.2% year (r = -0.58, P < 0.001). Normalized LV stroke volume fell at -1.1 ml m year (r = -0.47, P = 0.001), normalized LV ejection rate at -3.8 ml s m year (r = -0.43, P < 0.005) and normalized LV filling rate at -4.1 ml s m year (r = -0.44, P < 0.005). Also, RV wall thickening fraction decreased with age (slope = -1% year , P = 0.008). RV ejection rate decreased at -3.6 ml s m year (P = 0.002) and the normalized average RV filling rate dropped at -3.7 ml s m year (P < 0.0001). End-systolic RV sphericity index also dropped with age (r = -0.33, P = 0.02). Many observed changes parallel previously reported data in human and animal studies. These measured biventricular functional declines in hearts with ageing from the closest experimental primate species to man underscore the utility of the baboon model for investigating mechanisms related to heart ageing.
已全面描述非人类灵长类动物心血管功能的生命历程变化。随着双心室射血分数和充盈率相应降低，发现与年龄相关的左心室每搏量和心输出量的正常化下降。雄性和雌性狒狒的左心室心肌质量指数也出现了与年龄相关的下降，下降速度相似。随着年龄的增长，右心室功能出现收缩功能下降，与左心室相似。还发现了右心室容积变化的速率和方向存在性别差异，以及右心室收缩末期的球形度降低。这些结果证实了狒狒是研究衰老相关心血管功能下降的合适模型。
之前的研究报告了心脏功能随年龄增长而下降。本研究旨在确定经过充分特征描述的狒狒模型中双心室心脏功能的变化。心脏磁共振成像（CMR）测量了 47 只狒狒（22 只雌性，年龄 4-23 岁）的关键双心室参数。协方差分析（ANCOVA）评估了性别和年龄变化，P 值小于 0.05 被认为具有统计学意义。将心搏量、心输出量和其他心脏功能参数归一化为体表面积。雄性（M）和雌性（F）的左心室（LV）心肌质量指数（M：-1.2 g m 年 ，F：-0.9 g m 年 ）以相似的速率与年龄相关下降。LV 射血分数以-0.96%/年的速度下降（r=-0.43，P=0.002），右心室（RV）射血分数以-1.2%/年的速度下降（r=-0.58，P<0.001）。左心室每搏量的正常化下降速度为-1.1ml m 年 （r=-0.47，P=0.001），左心室射血率的正常化下降速度为-3.8ml s m 年 （r=-0.43，P<0.005），左心室充盈率的正常化下降速度为-4.1ml s m 年 （r=-0.44，P<0.005）。此外，RV 壁增厚分数随年龄下降（斜率为-1%/年，P=0.008）。RV 射血率以-3.6ml s m 年 的速度下降（P=0.002），正常化平均 RV 充盈率以-3.7ml s m 年 的速度下降（P<0.0001）。收缩末期 RV 球形指数也随年龄下降（r=-0.33，P=0.02）。许多观察到的变化与之前在人类和动物研究中的报告数据平行。这些从最接近人类的实验灵长类物种中测量的与年龄相关的双心室心脏功能下降，突显了狒狒模型在研究与心脏衰老相关的机制方面的实用性。
