Nonlinear regulation of capillary perfusion in relation to ambient pO2 changes in skeletal muscle
Nonlinear regulation of capillary perfusion in relation to ambient pO2 changes in skeletal muscle
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DOI：
10.1007/s00421-005-1315-6
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发表时间：
2005-06-01
影响因子：
3
通讯作者：
Kamiya, A
中科院分区：
文献类型：
--
作者：
Shibata, M;Ichioka, S;Kamiya, A
为了研究 O-2 转运到组织的过程，我们研究了如何根据骨骼肌中组织 O-2 水平的变化来控制毛细血管灌注。通过活体显微镜测量不同环境氧张力（pO(2)）下兔细肌的毛细血管红细胞（RBC）速度和灌注毛细血管募集。随着渗液 pO(2) 水平的增加，红细胞速度和毛细血管募集均显着降低，并且根据速度和募集数据计算的毛细血管灌注与渗液 pO(2) 水平之间的关系明显产生了拟合 S 形曲线的非线性相关性。毛细血管灌注显着减少或增加，高于或低于约 40 Torr 的饱和 pO(2) 水平，其中血红蛋白的 O-2 解离曲线改变斜率。这些发现支持这样的假设：微脉管系统通过感知组织的代谢需求而拥有内在的、有效的流量控制机制，与血红蛋白的 O-2 饱和度密切相关。
To study the process of O-2 transport to tissue, we investigated how capillary perfusion is controlled in response to changes in tissue O-2 levels in skeletal muscle. Capillary red blood cell (RBC) velocity and perfused capillary recruitment were measured in rabbit tenuissimus muscle at various ambient oxygen tensions (pO(2)) by intravital microscopy. Both RBC velocity and capillary recruitment significantly decreased as the pO(2) level of the suffusate was increased, and the relationship between capillary perfusion, calculated from the velocity and recruitment data, and the pO(2) level of the suffusate clearly yielded a nonlinear correlation that fitted a sigmoidal curve. Capillary perfusion dramatically decreases or increases above or below a suffusate pO(2) level of around 40 Torr, where the O-2 dissociation curve of hemoglobin changes slope. These findings support the hypothesis that microvasculature possesses an intrinsic, effective flow-control mechanism by sensing the metabolic demands of tissue, intimately related to the O-2 saturation of hemoglobin.