Venous smooth muscle tone and responsiveness in older adults.
Venous smooth muscle tone and responsiveness in older adults.
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老年人的静脉平滑肌张力和反应性。
DOI：
10.1152/japplphysiol.00448.2006
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Farquhar,WilliamB
中科院分区：
文献类型：
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作者：
Young,ColinN;Stillabower,MichaelE;DiSabatino,Angela;Farquhar,WilliamB
老年人的静脉顺应性低于年轻人。静脉平滑肌张力和反应性的改变可能导致静脉顺应性的年龄相关差异。确定交感神经激活的影响[冷加压试验（冷加压试验）;节律性缺血性握力（节律性缺血性握力）]和平滑肌张力的内皮非依赖性降低[舌下含服硝酸甘油（硝酸甘油）]对年轻人和老年人静脉顺应性的影响，采用静脉闭塞体积描记法测量了12名年轻（22 ± 1岁）和12名老年（65 ± 1岁）仰卧位受试者的前臂和小腿静脉顺应性。在基线、冷加压试验和节律性缺血性握力试验期间以及硝酸甘油给药后评估静脉顺应性。所有压力-容积关系均采用二次回归方程，以β 1和β 2作为静脉顺应性的指标。使用重复测量ANOVA确定年龄和试验对静脉顺应性的影响。基线时，老年人的小牛回归参数β1（0.0639 ± 0.0126 vs. 0.0503 ± 0.0059，年轻人vs.老年人;P< 0.05）和β2（−0.00054 ± 0.00011 vs. −0.00041 ± 0.00005，年轻人vs.老年人;P< 0.05）显著更低。同样，基线时老年人的前臂回归参数β 1和β 2较低。静脉顺应性不受冷加压试验，节律性缺血性握力，或舌下含服硝酸甘油在任何一组。数据表明，与年轻人相比，老年人的前臂和小腿静脉顺应性较低。然而，这种差异可能无法解释平滑肌张力或反应性的改变。
Venous compliance is lower in older adults compared with younger adults. It is possible that alterations in venous smooth muscle tone and responsiveness may contribute to the age-related differences in venous compliance. To determine the effects of sympathetic activation [cold pressor test (cold pressor test); rhythmic ischemic handgrip (rhythmic ischemic handgrip)] and endothelium-independent decreases in smooth muscle tone [sublingual nitroglycerin (nitroglycerin)] on venous compliance in young and older adults, forearm and calf venous compliance was measured in 12 young (22 ± 1 yr) and 12 old (65 ± 1 yr) supine subjects using venous occlusion plethysmography. Venous compliance was assessed at baseline, during the cold pressor test and rhythmic ischemic handgrip tests, and after nitroglycerin administration. All pressure-volume relationships were modeled with a quadratic regression equation, and β1and β2were used as indexes of venous compliance. A repeated-measures ANOVA was used to determine the effect of the age and trial on venous compliance. Calf regression parameters β1(0.0639 ± 0.0126 vs. 0.0503 ± 0.0059, young vs. older;P< 0.05) and β2(−0.00054 ± 0.00011 vs. −0.00041 ± 0.00005, young vs. older;P< 0.05) were significantly less in older adults at baseline. Similarly, forearm regression parameters, β1and β2were lower in older adults at baseline. Venous compliance was not effected by the cold pressor test test, rhythmic ischemic handgrip, or sublingual nitroglycerin in either group. Data suggest that forearm and calf venous compliance is lower in older adults compared with young. However, this difference probably cannot be explained by alterations in smooth muscle tone or responsiveness.