Effects of aging on cardiac output, regional blood flow, and body composition in Fischer-344 rats
Effects of aging on cardiac output, regional blood flow, and body composition in Fischer-344 rats
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DOI：
10.1152/jappl.1998.85.5.1813
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发表时间：
1998-11-01
影响因子：
3.3
通讯作者：
Duan, CP
中科院分区：
文献类型：
--
作者：
Delp, MD;Evans, MV;Duan, CP
本研究的目的是确定成熟和衰老对清醒幼年（2月龄）、成年（6月龄）和老年（24月龄）雄性Fischer-344大鼠心输出量、心输出量分布、组织血流量（通过使用放射性微球技术测定）和身体组成的影响。幼龄大鼠的心输出量（51 +/- 4 ml/min）低于成年大鼠（106 +/- 5 ml/min）或老年大鼠（119 +/- 10 ml/min），但各组之间的心脏指数无差异。大部分组织的心输出量的比例并不随年龄的增长而变化。然而，幼年大鼠的心输出量流向脑和脊髓组织以及骨骼肌的比例高于两个成年组。此外，老年大鼠有较大的百分比心输出量的脂肪组织和较低的百分比心输出量的皮肤和生殖组织比青少年和成年大鼠。年龄的差异对大多数组织的质量特异性灌注率也几乎没有影响。然而，幼年大鼠胰腺、胃肠道、甲状腺和甲状旁腺以及肾脏的血流量低于成年大鼠，老年大鼠股直肌、脾脏、甲状腺和甲状旁腺以及前列腺的白色部分的血流量低于成年大鼠。与成年和老年动物相比，幼年大鼠的体重由较低的脂肪量百分比和较大比例的脑和脊髓、心脏、肾脏、肝脏和骨骼肌组成。相对于年轻成年大鼠，老年动物的体重具有更大的脂肪组织质量百分比和更低的骨骼肌和皮肤质量百分比。这些数据表明，成熟和老化的心输出量的分布有显着的影响，但相对较小的影响，在清醒的大鼠特定质量的组织灌注率。老年相关的改变心输出量分布的脂肪和皮肤组织似乎与增加的百分比体脂和皮肤质量的分数的减少，分别，而减少的部分心输出量针对生殖组织的老年大鼠似乎是有关的质量特定的血流减少前列腺。
The purpose of this study was to determine the effects of maturation and aging on cardiac output, the distribution of cardiac output, tissue blood flow (determined by using the radioactive-microsphere technique), and body composition in conscious juvenile (2-mo-old), adult (6-mo-old), and aged (24-mo-old) male Fischer-344 rats. Cardiac output was lower in juvenile rats (51 +/- 4 ml/min) than in adult (106 +/- 5 ml/min) or aged (119 +/- 10 ml/min) rats, but cardiac index was not different among groups. The proportion of cardiac output going to most tissues did not change with increasing age. However, the fraction of cardiac output to brain and spinal cord tissue and to skeletal muscle was greater in juvenile rats than that in the two adult groups. In addition, aged rats had a greater percent cardiac output to adipose tissue and a lower percent cardiac output to cutaneous and reproductive tissues than that in juvenile and adult rats. Differences in age also had little effect on mass-specific perfusion rates in most tissues. However, juvenile rats had lower flows to the pancreas, gastrointestinal tract, thyroid and parathyroid glands, and kidneys than did adult rats, and aged rats had lower flows to the white portion of rectus femoris muscle, spleen, thyroid and parathyroid glands, and prostate gland than did adult rats. Body mass of juvenile rats was composed of a lower percent adipose mass and a greater fraction of brain and spinal cord, heart, kidney, liver, and skeletal muscle than that of the adult and aged animals. Relative to the young adult rats, the body mass of aged animals had a greater percent adipose tissue mass and a lower percent skeletal muscle and skin mass. These data demonstrate that maturation and aging have a significant effect on the distribution of cardiac output but relatively little influence on mass-specific tissue perfusion rates in conscious rats. The old-age-related alterations in cardiac output distribution to adipose and cutaneous tissues appear to be associated with the increases in percent body fat and the decreases in the fraction of skin mass, respectively, whereas the decrease in the portion of cardiac output directed to reproductive tissue of aged rats appears to be related to a decrease in mass-specific blood flow to the prostate gland.