Susic D, Nunez E, Hosoya K, Frohlich E D
Division of Research, Alton Ochsner Medical Foundation, New Orleans, Louisiana 70121, USA.
J Hypertens. 1998 Feb;16(2):231-7. doi: 10.1097/00004872-199816020-00014.
To delineate hypertension-related and age-related changes in coronary hemodynamics and to assess the role of myocardial (i.e. left ventricular) hypertrophy and cardiac fibrosis in inducing progressive deterioration of coronary flow reserve associated both with hypertension and with aging.
Systemic and coronary hemodynamics (using radionuclide-labeled microspheres), right ventricular, left ventricular, and aortic mass indexes, and ventricular hydroxyproline concentrations (an estimate of collagen) in normotensive Wistar-Kyoto and spontaneously hypertensive rats aged 22, 35, and 65 weeks were determined.
Spontaneously hypertensive rats of all ages had greater left ventricular and aortic masses, greater collagen concentrations in both ventricles, a lower coronary flow reserve, and greater minimal coronary vascular resistance after administration of dipyridamole than did Wistar-Kyoto rats. Despite spontaneously hypertensive rats having only left ventricular hypertrophy, coronary hemodynamics were impaired to the same extent in both ventricles. Progressive increases in myocardial collagen concentration, decreases in coronary flow reserve, and increases in minimal coronary vascular resistance were observed in rats of both strains with aging. A positive correlation and linear regression between myocardial collagen concentration and minimal vascular resistance were found for both ventricles of rats of both strains.
Both aging and hypertension adversely affected the coronary circulation; furthermore, these effects appeared to be additive. Cardiac fibrosis, but not hypertrophy, might play a role in progressive deterioration of coronary hemodynamics in aging and hypertension and could provide an explanation for the diastolic dysfunction encountered clinically in older patients with hypertension.
描述与高血压和年龄相关的冠状动脉血流动力学变化，并评估心肌（即左心室）肥厚和心脏纤维化在导致与高血压和衰老相关的冠状动脉血流储备逐渐恶化中所起的作用。
测定22周、35周和65周龄的正常血压Wistar-Kyoto大鼠和自发性高血压大鼠的全身和冠状动脉血流动力学（使用放射性核素标记的微球）、右心室、左心室和主动脉质量指数以及心室羟脯氨酸浓度（胶原蛋白的一种估计）。
与Wistar-Kyoto大鼠相比，各年龄段的自发性高血压大鼠左心室和主动脉质量更大，两个心室的胶原蛋白浓度更高，冠状动脉血流储备更低，给予双嘧达莫后最小冠状动脉血管阻力更大。尽管自发性高血压大鼠只有左心室肥厚，但两个心室的冠状动脉血流动力学受损程度相同。随着年龄增长，两种品系的大鼠均观察到心肌胶原蛋白浓度逐渐增加、冠状动脉血流储备降低以及最小冠状动脉血管阻力增加。两种品系大鼠两个心室的心肌胶原蛋白浓度与最小血管阻力之间均存在正相关和线性回归关系。
衰老和高血压均对冠状动脉循环产生不利影响；此外，这些影响似乎具有叠加性。心脏纤维化而非肥厚可能在衰老和高血压过程中冠状动脉血流动力学的逐渐恶化中起作用，并可为老年高血压患者临床上遇到的舒张功能障碍提供解释。
