EFFECT OF AGE ON ELASTICITY OF MAJOR BRAIN ARTERTIES
EFFECT OF AGE ON ELASTICITY OF MAJOR BRAIN ARTERTIES
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DOI：
10.1139/y65-018
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发表时间：
1965-01-01
影响因子：
2.1
通讯作者：
BURTON, AC
中科院分区：
文献类型：
--
作者：
BUSBY, DE;BURTON, AC
在以前的外周动脉的工作中，拉普拉斯定律已被应用于压力-容积数据，以产生弹性常数和壁中弹性蛋白和胶原纤维的功能的相互关系，以及随年龄的变化。对2至90岁的尸检标本也进行了类似的脑动脉分析。准确测量动脉段的体积（微米注射器）和压力（电测压计）。绝对容积是通过用负压使动脉塌陷来获得的，并且从曲线推导出血管的“未拉伸周长”。绘制了张力-周长曲线。这些显示了随着拉伸程度的增加而增加的特征性斜率（增加的“弹性”或“刚度”），解释为当胶原纤维达到其未拉伸长度时胶原纤维的连续“募集”。在年龄超过30岁的血管中，扩张引起的动脉长度增加非常小，可以忽略不计。在生理范围内的压力下达到最大斜率（刚度）。30 - 90岁血管的最大拉伸为26 - 38%。这低于外周动脉，80岁以上的除外。老化本身主要表现为使50%的胶原纤维达到其未拉伸长度所需的拉伸减少，即“松弛度”。年轻血管的拉伸率为30%，老年血管为20%。与外周动脉不同，脑动脉的最大硬度（与其总胶原含量相关）并未随年龄而显著增加。高压下壁面杨氏模量的平均值为1.93 ± 0.67 × 107达因/平方厘米。随着年龄的增长，管腔直径的壁的厚度没有显着的变化被发现。它的结论是，主要的脑动脉比周围动脉的可比直径扩张，特别是在青年。扩张性随着年龄的增长而降低，主要是因为胶原纤维的“松弛程度”降低。在生理压力下，对扩张的主要阻力是由于胶原纤维而不是弹性蛋白纤维，弹性蛋白纤维在组织学上似乎比外周动脉中的丰富度低，但在弹性内动脉中除外。
In previous work on peripheral arteries the law of Laplace has been applied to the pressure-volume data to yield the elastic constants and interrelation of function of elastin and collagenous fibers in the wall, and the changes with age. Similar analysis of major brain arteries has been made on autopsy specimens, aged 2 to 90. Volume (micrometer syringe) and pressure (electromanometer) in arterial segments were accurately measured. Absolute volumes were obtained by collapsing the artery with negative pressure, and the "unstretched circumferences" of the vessel were deduced from the curves. Tension-circumference curves were constructed. These showed the characteristic increasing slope (increased "elastance" or "stiffness") with increasing degree of stretch, interpreted as successive "recruitment" of collagen fibers as they reach their unstretched length. Increases in arterial length with distension were very small and negligible in vessels older than 30 years. Maximum slope (stiffness) was reached at pressures in the physiological range. The maximal stretch was 26 to 38% for vessels aged 30 to 90 years. This is less than for peripheral arteries, except those over 80 years old. Ageing showed itself mainly in reduction of the stretch required to bring 50% of the collagen fibers to their unstretched length, i.e. in the "degree of slackness". This was 30% stretch for younger vessels, 20% for the older. Unlike the peripheral arteries, the brain arteries show no significant increase with age in the maximal stiffness (related to their total collagen content). The mean vlaue of the Young''s modulus of the wall at high pressures was 1.93 [plus or minus] 0.67 107 dynes/sq.cm. No significant change in thickness of the wall of lumen diameter with age was found. It is concluded that the major brain arteries are less distensible than peripheral arteries of comparable diameter, particularly in youth. Distensibility decreases with age, mainly because the "degree of slackness" of the collagen fibers is reduced. At physiological pressures the major resistance to distension is due to the collagen fibers rather than to the elastin fibers, which appear histologically to be less abundant, except in the elastica interna, than in peripheral arteries.