Suppr超能文献

低流速下毛细血管后微静脉中碰撞率和碰撞效率对红细胞聚集的作用。

Contributions of collision rate and collision efficiency to erythrocyte aggregation in postcapillary venules at low flow rates.

作者信息

Kim Sangho, Zhen Janet, Popel Aleksander S, Intaglietta Marcos, Johnson Paul C

机构信息

Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093-0412, USA.

出版信息

Am J Physiol Heart Circ Physiol. 2007 Sep;293(3):H1947-54. doi: 10.1152/ajpheart.00764.2006. Epub 2007 Jul 6.

Abstract

Red blood cell aggregation at low flow rates increases venous vascular resistance, but the process of aggregate formation in these vessels is not well understood. We previously reported that aggregate formation in postcapillary venules of the rat spinotrapezius muscle mainly occurs in a middle region between 15 and 30 microm downstream from the entrance. In light of the findings in that study, the main purpose of this study was to test two hypotheses by measuring collision frequency along the length of the venules during low flow. We tested the hypothesis that aggregation rarely occurs in the initial 15-microm region of the venule because collision frequency is very low. We found that collision frequency was lower than in other regions, but collision efficiency (the ratio of aggregate formation to collisions) was almost nil in this region, most likely because of entrance effects and time required for aggregation. Radial migration of red blood cells and Dextran 500 had no effect on collision frequency. We also tested the hypothesis that aggregation was reduced in the distal venule region because of the low aggregability of remaining nonaggregated cells. Our findings support this hypothesis, since a simple model based on the ratio of aggregatable to nonaggregatable red blood cells predicts the time course of collision efficiency in this region. Collision efficiency averaged 18% overall but varied from 0 to 52% and was highest in the middle region. We conclude that while collision frequency influences red blood cell aggregate formation in postcapillary venules, collision efficiency is more important.

摘要

在低流速下红细胞聚集会增加静脉血管阻力,但这些血管中聚集体形成的过程尚未得到很好的理解。我们之前报道过,大鼠斜方肌毛细血管后微静脉中的聚集体形成主要发生在入口下游15至30微米之间的中间区域。鉴于该研究的结果,本研究的主要目的是通过测量低流速期间微静脉长度上的碰撞频率来检验两个假设。我们检验了这样一个假设,即微静脉最初的15微米区域很少发生聚集,因为碰撞频率非常低。我们发现该区域的碰撞频率低于其他区域,但该区域的碰撞效率(聚集体形成与碰撞的比率)几乎为零,这很可能是由于入口效应和聚集所需的时间。红细胞和右旋糖酐500的径向迁移对碰撞频率没有影响。我们还检验了另一个假设,即由于剩余未聚集细胞的聚集性低,微静脉远端区域的聚集减少。我们的研究结果支持了这一假设,因为基于可聚集与不可聚集红细胞比率的简单模型预测了该区域碰撞效率的时间进程。碰撞效率总体平均为18%,但从0到52%不等,在中间区域最高。我们得出结论,虽然碰撞频率会影响毛细血管后微静脉中红细胞聚集体的形成,但碰撞效率更为重要。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验