Tuma R F, Irion G L, Vasthare U S, Heinel L A
Am J Physiol. 1985 Sep;249(3 Pt 2):H485-91. doi: 10.1152/ajpheart.1985.249.3.H485.
The purpose of this investigation was to characterize the changes in regional blood flow and central hemodynamic measures that occur in the rat as a result of the aging process. The isotope-labeled microsphere technique was used to measure cardiac output and regional blood flows in conscious and anesthetized adult (12 mo) and senescent (24 mo) Fischer 344 virgin female rats. No significant changes were observed in central hemodynamic measurements or regional blood flows in conscious rats with the exception of a 25% reduction in splenic blood flow. Pentobarbital anesthesia significantly reduced cardiac index and heart rate but elevated total peripheral resistance and mean arterial blood pressure. There was a decrease in blood flow to skeletal muscle, spleen, duodenum, stomach, and brain tissue samples and increased hepatic arterial blood flow in both age groups. The use of anesthesia caused a greater reduction in the cardiac index and brain blood flow in the senescent anesthetized rats than in the adult rats. Heart and kidney blood flows were decreased by anesthesia in the senescent rats but not in the adult rats. Skeletal muscle blood flow, however, was significantly greater in the senescent anesthetized rats than in the younger anesthetized animals. Although body weight and organ weights of the liver, spleen, kidneys, stomach, heart, and brain were significantly greater for the senescent rats, no differences could be demonstrated in tibial length or lean body mass.
本研究的目的是描述衰老过程中大鼠局部血流和中心血流动力学指标的变化。采用同位素标记微球技术，测量清醒和麻醉状态下成年（12个月）及衰老（24个月）的Fischer 344未育雌性大鼠的心输出量和局部血流量。除脾血流量减少25%外，清醒大鼠的中心血流动力学指标和局部血流量未观察到显著变化。戊巴比妥麻醉显著降低心脏指数和心率，但提高总外周阻力和平均动脉血压。两个年龄组的骨骼肌、脾脏、十二指肠、胃和脑组织样本的血流量均减少，肝动脉血流量增加。与成年大鼠相比，衰老麻醉大鼠使用麻醉剂后心脏指数和脑血流量的降低幅度更大。衰老大鼠麻醉后心脏和肾脏血流量减少，成年大鼠则未减少。然而，衰老麻醉大鼠的骨骼肌血流量显著高于年轻麻醉动物。虽然衰老大鼠的体重以及肝脏、脾脏、肾脏、胃、心脏和脑的器官重量显著更大，但胫骨长度或瘦体重未显示出差异。
