Hachamovitch R, Wicker P, Capasso J M, Anversa P
Department of Pathology, New York Medical College, Valhalla 10595.
Am J Physiol. 1989 Jan;256(1 Pt 2):H66-73. doi: 10.1152/ajpheart.1989.256.1.H66.
To determine whether aging affects the coronary circulation, left and right ventricular coronary blood flow and vascular resistance at rest and after maximal vasodilation were measured by left atrial injection of radioactive microspheres in conscious, unrestrained male Fischer 344 rats at 4, 12, and 20 mo of age. As a function of age, maximal coronary blood flow per 100 g of tissue decreased by 43% in the left ventricle at both 12 and 20 mo, whereas a 44 and a 47% reduction was found in the right side of the heart at the same time intervals. Minimal coronary vascular resistance per 100 g of myocardium increased by 56 and 36% in the left ventricle and by 48 and 44% in the right at 12 and 20 mo, respectively. No change was found in total minimal coronary resistance for either ventricle despite an increase in myocardial mass. Maximal coronary blood flow per 100 g to the endocardium was depressed more than epicardial flow, leading to a 24% reduction in the endocardial-to-epicardial flow ratio at 20 mo. Coronary vascular reserve per 100 g, expressed as the increase in coronary blood flow during maximal coronary vasodilation, was greater in the right than in the left ventricle at all ages. It is concluded that the changes in coronary hemodynamics associated with maturation and aging are comparable with those seen in pressure overload hypertrophy with an increased vulnerability potential of the myocardium to ischemic episodes, particularly of the subendocardial region of the left ventricle.
为了确定衰老是否会影响冠状动脉循环，在4、12和20月龄的清醒、自由活动的雄性Fischer 344大鼠中，通过左心房注射放射性微球来测量静息状态和最大血管舒张后左、右心室的冠状动脉血流量和血管阻力。随着年龄的增长，在12和20月龄时，左心室每100 g组织的最大冠状动脉血流量均减少了43%，而在相同时间间隔内，右心室分别减少了44%和47%。在12和20月龄时，左心室每100 g心肌的最小冠状动脉血管阻力分别增加了56%和36%，右心室分别增加了48%和44%。尽管心肌质量增加，但两个心室的总最小冠状动脉阻力均未发现变化。与心外膜血流相比，20月龄时每100 g心内膜的最大冠状动脉血流量下降幅度更大，导致心内膜与心外膜血流比值降低了24%。在所有年龄段，以最大冠状动脉舒张期间冠状动脉血流量增加来表示的每100 g冠状动脉血管储备，右心室均大于左心室。结论是，与成熟和衰老相关的冠状动脉血流动力学变化与压力超负荷性肥大时的变化相当，心肌对缺血事件的易损性增加，尤其是左心室心内膜下区域。
