Augmented mesenteric and renal vasoconstriction during exercise in senescent Fischer 344 rats.
Augmented mesenteric and renal vasoconstriction during exercise in senescent Fischer 344 rats.
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衰老 Fischer 344 大鼠运动期间肠系膜和肾血管收缩增强。
DOI：
10.1152/jappl.1995.79.3.706
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Kregel,KC
中科院分区：
文献类型：
--
作者：
Kregel,KC
本研究的目的是检验以下假设：随着年龄的增长，在次最大和最大运动强度下，肠系膜和肾循环中的血管收缩更大。在成熟（12个月）和衰老（24个月）雄性Fischer 344大鼠进行分级跑步机运动之前和期间，测量动脉血压、心率和肠系膜、肾和髂（后肢）动脉血流速度。在轻度、中度和最大运动强度（约为最大摄氧量的45%、70%和100%）的跑步机跑步期间，成熟和衰老动物的动脉压升高相似，而老年组的心率升高较少（P < 0.05）。肠系膜和肾血流速度下降，血管阻力增加，从静息水平在两组中的分级运动，然而，肠系膜和肾血管阻力的增加幅度显着增加，在老年大鼠在中等和最大的工作负荷。在两组中，在每个运动强度下，后肢血流速度增加，阻力从静息水平下降。相反，内脏和肾脏的调整，在后肢流量和阻力的变化幅度是相似的两个年龄组在所有的运动强度。这些研究结果支持的假设，肠系膜和肾血管收缩增强衰老Fischer 344大鼠在中等和最大强度的运动，但不是在轻度的工作负荷。尽管存在这些区域性差异，但随着年龄的增长，在次最大或最大运动强度下，动脉压的维持并没有改变。
The purpose of this study was to test the hypothesis that vasoconstriction in the mesenteric and renal circulations is greater at both submaximal and maximal exercise intensities with advancing age. Arterial blood pressure, heart rate, and mesenteric, renal, and iliac (hindlimb) artery blood flow velocities were measured before and during graded treadmill exercise in mature (12 mo) and senescent (24 mo) male Fischer 344 rats. During treadmill running at mild, moderate, and maximal exercise intensities (approximately 45, 70, and 100% of maximal oxygen uptake), the increases in arterial pressure were similar in the mature and senescent animals, whereas heart rate rose less in the older group (P < 0.05). Mesenteric and renal flow velocities declined and vascular resistances increased from resting levels in both groups in response to graded exercise; however, the magnitudes of the increases in both mesenteric and renal vascular resistance were significantly augmented in the older rats at the moderate and maximal workloads. Hindlimb blood flow velocity increased and resistance declined from resting levels at each exercise intensity in both groups. In contrast to the visceral and renal adjustments, the magnitudes of the changes in both hindlimb flow and resistance were similar for the two age groups at all exercise intensities. These findings support the hypothesis that mesenteric and renal vasoconstriction is augmented in senescent Fischer 344 rats during exercise at moderate and maximal intensities but not at mild workloads. Despite these regional differences, the maintenance of arterial pressure is not altered at either submaximal or maximal exercise intensities with advancing age.