Microvascular development during normal growth and reduced blood flow: introduction of a new model.
Microvascular development during normal growth and reduced blood flow: introduction of a new model.
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正常生长期间的微血管发育和血流量减少：引入新模型。
DOI：
10.1152/ajpheart.1991.260.6.h1966
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Prewitt,RL
中科院分区：
文献类型：
--
作者：
Wang,DH;Prewitt,RL
本研究的目的是评估正常骨骼肌成熟过程中微血管的发育，并确定与需求减少引起的血流量减少相关的变化。对4周龄的大鼠进行单侧小脑扁桃体切除术以减少肌肉张力和一侧提睾肌的生长。三周后，通过双缝速度技术测量的总血流量减少到58 +/- 9%，通过放射性微球测量的总血流量减少到55 +/- 9%，与完整的对侧肌肉相比，肌肉更小。每克组织的血流量没有显著差异。通过闭路电视显微镜测量，在对照肌肉中，各级小动脉（1A-4A）的内径和壁横截面积以及每3A的4As数量随着年龄的增长而增加。拱状小动脉的长度增加了35%的完整的肌肉增长，但3A的数量保持不变。小动脉长度增加，但不成比例的肌肉质量。结果，大、小动脉密度随年龄增长而降低。因此，在正常骨骼肌成熟过程中，预先存在的小动脉变得细长，只有毛细血管前小动脉的数量增加，导致小动脉数量与组织质量的比率降低。单侧睾丸切除术抑制小动脉的生长，无论是在大小和数量。椎间盘切除术肌肉中1A直径的减小导致壁剪切率不变。流动诱导的剪切应力和/或生长因子的局部变化被认为是介导这些改变的可能机制。
The purpose of this study was to evaluate microvascular development during normal skeletal muscle maturation and to determine the alterations associated with decreased blood flow caused by a decrease in demand. Unilateral orchidectomy was performed on 4-wk-old rats to reduce muscle tension and growth of one cremaster muscle. Three weeks later, total blood flow was reduced to 58 +/- 9% measured by the dual-slit velocity technique and 55 +/- 9% by radioactive microspheres, and the muscle was smaller when compared with the intact contralateral muscle. Blood flow per gram of tissue was not significantly different. Measured by closed-circuit television microscopy, the internal diameters and wall cross-sectional areas of all orders of arterioles (1A-4A), and the number of 4As per 3A had increased with age in the control muscle. The arcading arterioles increased in length by 35% as the intact muscle grew, but the number of 3As remained unchanged. Arteriolar length increased but not in proportion to muscle mass. As a result, large and small arteriolar density decreased with age. Thus, during normal skeletal muscle maturation, preexisting arterioles became elongated and only precapillary arterioles increased in number, resulting in a decreased ratio of arteriolar number to tissue mass. Unilateral orchidectomy inhibited the growth of arterioles in both size and number. A reduced diameter of the 1A in the orchidectomy muscle resulted in unchanged wall shear rate. Flow-induced shear stress and/or local changes in growth factors are suggested as possible mechanisms mediating the alterations.