LENGTH-TENSION RELATIONSHIP OF SMOOTH-MUSCLE OF HOG CAROTID-ARTERY
LENGTH-TENSION RELATIONSHIP OF SMOOTH-MUSCLE OF HOG CAROTID-ARTERY
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DOI：
10.1161/01.res.33.3.275
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发表时间：
1973-01-01
影响因子：
20.1
通讯作者：
MURPHY, RA
中科院分区：
文献类型：
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作者：
HERLIHY, JT;MURPHY, RA
动脉平滑肌的长度-张力关系是通过从猪颈动脉中层提取的血管条来确定的。组织学检查显示，条带（1）没有外膜，（2）由平行于条带长轴定向的平滑肌细胞组成。电子显微照片的测量结果表明，60% 的横截面积由平滑肌组成。在 L0（张力产生的最佳长度）处，条带的总横截面积在 0.3 至 0.8 mm2 之间变化。钾诱导的去极化是力发展的最有效刺激。去甲肾上腺素和电场刺激引起的反应分别是钾诱导去极化产生的反应的 70% 和 30%。在 L0 时，收缩系统的固有承载能力 (P0) 为 2.22 x 106dynes/cm2。当长度短于 L0 时，张力发展逐渐减弱，而当长度大于 L0 时，张力发展更快。在从较高长度到较低长度快速释放后确定被动长度-张力曲线，以避免张力引起的并发症。当长度低于 0.9 L0 时，被动张力可以忽略不计。在 L0 处，被动张力为 P0 的 10%。
The length-tension relationships for arterial smooth muscle were determined using vascular strips teased from the media of hog carotid arteries. Histological examination revealed that the strips were (1) free of adventitia and (2) composed of smooth muscle cells oriented parallel to the long axis of the strips. Measurements from electron micrographs indicated that 60% of the cross-sectional area consisted of smooth muscle. At L0(the optimal length for tension development) the total cross-sectional area of the strips varied from 0.3 to 0.8 mm2. Potassium-induced depolarization was the most effective stimulus for force development. Norepinephrine and electric field stimulation elicited responses which were 70% and 30%, respectively, of that produced by potassium-induced depolarization. At L0the intrinsic load-bearing capacity (P0) of the contractile system was 2.22 x 106dynes/cm2. Tension development fell off gradually at lengths shorter than L0and more rapidly at lengths greater than L0. Passive length-tension curves were determined after quick releases from higher to lower lengths to avoid complications arising from tone. Passive tension was negligible at lengths below 0.9 L0. At L0the passive tension was 10% of P0.