人股动脉牵拉后的顺应性变化

本文采用意外死亡青年男性的正常股动脉段６侧，测定其受牵拉后的压力－容积关系，并求出其顺应性。发现股动脉段拉伸后的Ｐ－Ｖ曲线也可用抛物线来拟合。不超出生理压范围时股动脉Ｐ－Ｖ曲线的非线性特性明显，但拉伸等程度增加后线性特性逐渐加强，伸长率等于或小于１５％时，顺应性无明显变化，伸长率等或大于２０％时，股动脉的顺应性明显下降，说明股动脉段拉伸１５％以下是安全的。     

人股动脉受牵拉后的顺应性变化

本文采用意外死亡青年男性的正常股动脉段6侧,测定其受牵拉后的压力—容积关系,并求出其顺应性。发现股动脉段拉伸后的P—V曲线也可用抛物线来拟合。不超出生理压范围时股动脉P-V曲线的非线性特性明显,但拉伸程度增加后线性特性逐渐加强,伸长率等于或小于15％时,顺应性无明显变化,伸长率等于或大于20％时,股动脉的顺应性明显下降,说明股动脉段拉伸15％以下是安全的。     

张力吻合动脉早期的结构成份与顺应性变化

目的：研究动脉张力吻合后2周内结构成份及顺应性变化规律。方法：在体测定狗股动脉张力吻合后不同时相点吻合口段的压力与直径相应的数据，计算出动脉的顺应性进行拟合后，建立顺应性与平均血压的关系。观测后的动脉常规切片，分别对弹性纤维、胶原纤维和平滑肌行特殊染色，测量各结构成份相对含量。结果：随术后时间延长，张力吻合动脉吻合口段的顺应性较吻合前逐渐降低，术后14d降低最显著。术后1d和5d弹性纤维变化无显著性差异。术后1～14d胶原纤维呈增加趋势，胶原纤维与弹性纤维含量的比值术后逐日增高。结论：动脉张力吻合后近期吻合口段的可扩张能力较正常动脉有明显减弱，其变化与结构成份改变相关。     

动脉牵拉后横断面积的图象分析

本文采用MAS－1图象分析系统，对受拉伸后的狗股动脉横断面积进行了测量，结果发现，受拉伸后的动脉，其横断面积随拉伸率的上升而减小，动脉横断面积可作为研究动脉受拉伸后形态结构变化的重要参数之一，本文认为，应用MAS－1图象分析系统对生物医学组织切片的形态参数测量，可获得较准确的结果。     

动脉吻接后的顺应性变化

本实验通过在体测定狗股动脉端端吻合前及吻合后不同时相点的压力与直径相应数据，推导出动脉吻接前后的顺应性，找出顺应性与平均血压的关系。结果表明；动脉吻接后吻合口段的顺应性较吻接前逐日下降，吻俣扣１４天下降最明显，以后有所回升。     

动脉正常吻接和张力吻接后顺应性对比研究

通过在体测定狗股动脉正常吻接和张力吻接后不同时相点吻合口段的压力与直径相应的数据，从而得出动脉在正常及张力吻接后的顺应性，以及顺应性与平均血压的关系。结果表明在各时相点，张力吻接组吻合口段动脉的顺应性均低于正常吻接组。反映出动脉张力吻接后吻合口段的可扩张能力较正常吻接动脉有明显减弱，术后14天减弱最显著。张力吻合对吻合口段动脉的功能有较大影响。     

动脉吻接后的顺应性变化

动脉吻接后的顺应性变化余汇洋，朱星红，李振强，糜建红第三军医大学重庆６３００３８血管的顺应可作为一个反映血管可扩张性的较好的参数。对吻接后血管顺应性的研究，有助于了解吻接段血管的功能状态。本实验应用ＨＬＣ－Ｉ型生物活组织力学试验机，在体测定狗股动脉端...     

动脉正常吻接和张力吻接后顺应性对比研究

通过在体测定狗股动脉正常吻接和张力吻接后不同时相点吻合口段的压力与直接相应的数据,从而得出动脉在正常及张力吻接后的顺应性,以及顺应性与平均血压的关系。结果表明：在各时相点,张力吻接组吻合口段动脉的顺应性均低于正常吻接组,反映出动脉张力吻接合吻合口段的可扩张能力较正常吻接动脉有明显减弱,术后14天减弱最显著,张力吻合对吻合口段动脉的功能有较大影响。     

张力吻合对动脉顺应性影响的实验研究

目的 探讨动脉张力吻合后其顺应性的变化。方法 在体测定犬股动脉非吻合、正常吻合及张力吻合后不同时相点吻合口段的压力与直径相应的数据，推算动脉非吻合、正常及张力吻合后的顺应性，确定动脉顺应性与平均血压的关系。结果 在各时相点，吻合组动脉的顺应性低于非吻合组，张力吻合组动脉的顺应性低于正常吻合组，术后14d降低最显著。结论 动脉张力吻合术后近期吻合口段的可扩张能力较正常吻合动脉及正常动脉有明显减弱，张力吻合对吻合口段动脉的功能有较大影响。     

动脉张力吻合后的顺应性变化

通过在体测定狗股动脉非吻合、正常吻合及张力吻合后不同时相点吻合口段的压力与直径相应的数据 ,计算出动脉非吻合、正常及张力吻合后的顺应性 ,顺应性与平均血压曲线用幂函数 C=bem Pa进行拟合 ,建立顺应性与平均血压的关系。结果表明 :在各时相点 ,吻合组的顺应性低于非吻合组 ,张力吻合组吻合口段动脉的顺应性低于正常吻合组 ,术后 14 d降低最显著。反映出动脉张力吻合术后近期吻合口段的可扩张能力较正常吻合动脉及正常动脉有明显减弱。张力吻合对吻合口段动脉的功能有较大影响     

Changes of diameter and length in cylindrical segments of canine femoral arteries during activation at different pressures

Changes in diameter and length of cylindrical segments of canine femoral arteries were recorded at different transmural pressures, and these dimensional changes have been compared with those of rings and longitudinal strips of the vessel wall. The segments responded to stimulation (noradrenaline or 40 mmol/l of potassium) with a reduction of the diameter at all transmural pressures applied. The length of the segments increased during stimulation when the transmural pressure was zero, but decreased at higher transmural pressures (60–70 mm Hg). This shortening at normal transmural pressure was converted to a small lengthening when the segment was stretched to in situ length. The factors determining these responses are discussed.This work was supported by grants from the Deutsche Forschungsgemeinschaft (Go 130/23)     

Radial and longitudinal distensibility of arterial microvessels in the mesentery and their dependence on extravascular structures

Summary The distensibility characteristics of arterial microvessels were measured in isolated and perfused segments of canine mesenteric membrane. Pressure-diameter-relations were found to be concave to the pressure axis with a plateau of unchanging diameter seen in approximately 50% of the vessels at pressures above 70 mm Hg. The total change of diameter averaged approximately 15% over the pressure range between 0 and 170 mm Hg. Changes of vessel length (on average 15%) were observed in those vessels which were not fixed at their maximum length by the surrounding connective tissue fibres. A correlation was found between the changes in length and the changes in diameter, indicating that both are influenced by the mechanical properties and the tension in the extravascular structures. The modulus of volume elasticity of arterial microvessels not fixed at constant length was found to increase with increasing pressure, reaching values of approximately 1.0·10⁶ dynes/cm² at a perfusion pressure of 100 mg Hg; for vessels with constant length values of up to 4.0·10⁶ dynes/cm² were obtained. It is concluded that the peripheral microvessels exhibit a greater stiffness than larger arteries and in part derive their mechanical properties from the properties of the surrounding tissues.Partially presented at the 38. Meeting of the German Physiological Society, Erlangen, 1970 [Pflügers Arch.319, R 34 (1970)].     

Dynamic compliance of arterial grafts.

A cantilever transducer has been developed which allows measurements of diastolic diameter and diameter change in response to pulse pressure in dissected blood vessels during sterile procedures. Preliminary results indicate that it will detect subtle changes in wall elastic properties of arterial grafts at subtle changes in wall elastic properties of arterial grafts at and following implantation, which changes may influence graft function. Compliance, the percentage change in volume per unit pressure, was greater in normal canine femoral artery than in autogenous vein grafts (AVG). Two new graft materials were tested. Mesh-covered modified human umbilical cord vein (DBM) was similar in compliance to AVG but more compliant than double-velour Dacron. Diastolic diameter changes were also recorded. After 2 wk, all three graft materials had increased in diameter: AVG by 8%, DBM by 6%, and Dacron by 5%. After 3 mo, AVG diameter increased by 24%.     

正常大鼠不同动脉血管应力-应变分布的比较

通过充压实验和无载荷状态及零应力状态,我们研究了16只雄性大鼠的胸主动脉、腹主动脉、左颈总动脉、左股动脉和左肺动脉的形态学和应力－应变分布特征,并比较了不同血管间的差异。结果表明,血管的内外周长、管壁和管腔面积、管壁厚度、管壁厚度与内半径之比以及在不同压力负荷下血管外直径的变化,五条动脉之间有显著差异（P＜0.01）。展开角在肺动脉最大,而胸主动脉最小（P＜0.01）。残余应变绝对值和残余应变梯度在股动脉最大,而在胸主动脉最小（P＜0.01）。应力－应变关系分析证明,在周向上,股动脉最硬;在轴向上,胸主动脉最硬。而在这两个方向上,肺动脉最软。本实验表明,无论在形态学指数方面,还是在生物力学特征方面,五条动脉血管间都有显著差异。     

Sustained Axial Loading Lengthens Arteries in Organ Culture

Although it has been recognized for many years that arteries in vivo exist under significant axial strain, studies of the adaptation of arteries to elevated axial strain have only recently been conducted. To determine the effects of sustained elevation of axial loading on arterial structure and function, axial stresses of 250 kPa or greater were applied to porcine common carotid arteries maintained in a perfusion organ culture system for 7 days at physiologic pressure and flow conditions. Our results demonstrated that axial stretch could lead to an increase in unloaded length that was proportional to the axial stretch ratio (stretched length divided by unloaded length) when the axial stretch ratio was above a threshold value of 2.14. Below this threshold, no significant length change occurred. Above this threshold, a significant increase in unloaded length (13 ± %,) and the number of smooth muscle cell nuclei (20 ± 7%) was observed. Permanent length change was associated with a significant decrease in axial stiffness, and the maximum elongation achieved was limited by rupture of the arterial wall. All tested arteries demonstrated good viability and strong vasomotor responses. These results show that arteries in organ culture can elongate under sustained axial loading.