Conducted vascular responses: Communication across the capillary bed
Conducted vascular responses: Communication across the capillary bed
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DOI：
10.1006/mvre.1998.2076
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发表时间：
1998-07-01
影响因子：
3.1
通讯作者：
Ellsworth, ML
中科院分区：
文献类型：
--
作者：
Collins, DM;McCullough, WT;Ellsworth, ML
传导的血管舒缩反应对于血流的有效分布是重要的，尽管这些反应的启动机制尚不清楚。ATP是一种由循环红细胞在低P-O2和低pH条件下释放的物质，这两种条件与供应相对于需求减少有关，已被证明在一阶和二阶小动脉内应用ATP可启动传导血管舒张。由于这种低P-O2和低pH条件很可能发生在脉管系统的静脉侧，我们使用活体视频显微镜评估了小动脉和毛细血管网络对将ATP应用于saran覆盖的仓鼠颊袋牵开肌的小静脉的反应。10(-6) M ATP的40和400 pi的腔内施用导致从施用部位上游450 μ M的小动脉直径呈剂量依赖性增加。这些小动脉直径的变化伴随着红细胞通量的显著增加。在毛细血管中，红细胞通量在ATP的作用下增加了一倍。由于NO先前被确定参与血管对小动脉腔内ATP的反应，我们评估了它在这些反应中的作用。我们发现，在使用ATP之前，全身给药L-NAME可以消除任何传导反应，而全身给药l -精氨酸可以逆转L-NAME的这种作用。这些数据表明，在静脉微血管中发现的低P-O2和低pH条件下，红细胞释放的ATP可能在供应改变时分配灌注中起作用。(C) 1998学术出版社。
Conducted vasomotor responses are important for the effective distribution of blood flow, although the mechanism by which these responses are initiated is not well understood. ATP, a substance which is released from circulating red blood cells in response to low P-O2 and low pH, two conditions which are associated with decreased supply relative to demand, has been shown to initiate conducted vasodilation following its intraluminal application in first and second order arterioles. Since such low P-O2 and low pH conditions would most likely occur on the venous side of the vasculature, we evaluated the response of the arteriolar and capillary networks to application of ATP into venules in the Saran-covered hamster cheek pouch retractor muscle using in vivo video microscopy. Intraluminal application of 40 and 400 pi of 10(-6) M ATP resulted in dose-dependent increases in arteriolar diameter >450 mu m upstream from the site of application. These changes in arteriolar diameter were accompanied by significant increases in red blood cell flux. In capillaries, red blood cell flux doubled in response to ATP administration. Since NO was previously determined to be involved in the vascular response to intraluminal ATP in arterioles, we evaluated its role in these responses. We found that systemic administration of L-NAME prior to ATP application eliminated any conducted response and this effect of L-NAME was reversed by the systemic administration of L-arginine. These data suggest that ATP, which is released from red blood cells in response to low P-O2 and low pH, conditions which would be found in the venular microvasculature, may serve a role in distributing perfusion in response to alterations in supply. (C) 1998 Academic Press.