Shen J, Luscinskas F W, Gimbrone M A, Dewey C F
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Microcirculation. 1994 Apr;1(1):67-78. doi: 10.3109/10739689409148263.
To determine whether fluid flow influences the action of soluble vasoactive agonists on vascular endothelium.
Confluent monolayers of bovine aortic endothelial cells (BAEC) were cultured on glass coverslips, prelabeled with the Ca(2+)-sensitive dye fura-2, and placed in a parallel-plate flow chamber designed to generate defined laminar fluid flow. Cytosolic free Ca2+ concentration ([Ca2+]i) in individual BAEC was monitored during perfusion with medium containing adenine nucleotide under defined flow conditions.
Continuous perfusion with ATP (0.3-3.0 microM) or ADP (0.1-1.0 microM) evoked repetitive oscillations in [Ca2+]i in individual BAEC. The frequency of the [Ca2+]i oscillations was dependent on both nucleotide concentration and levels of applied shear stress; at constant bulk concentration of nucleotide, the frequency increased with shear stress. Stopping flow in the continuous presence of agonists immediately extinguished the oscillatory response. Elimination of extracellular Ca2+ did not inhibit the [Ca2+]i oscillations. In the presence of nonhydrolyzable nucleotide analog, ATP gamma S or ADP beta S, application of flow resulted in similar shear-dependent [Ca2+]i oscillations, suggesting that flow modulation of the [Ca2+]i response was not simply due to depletion of ATP or ADP in the vicinity of BAEC monolayers as a result of hydrolysis of nucleotides by ectonucleotidases.
These findings suggest that local hemodynamic conditions may modulate the action of vasoactive agents on the vascular endothelium in vivo.
确定流体流动是否会影响可溶性血管活性激动剂对血管内皮的作用。
将汇合的牛主动脉内皮细胞（BAEC）单层培养在玻璃盖玻片上，用Ca(2+)敏感染料fura-2进行预标记，然后置于设计用于产生特定层流的平行板流动腔室中。在特定流动条件下，用含腺嘌呤核苷酸的培养基灌注时，监测单个BAEC中的胞质游离Ca2+浓度（[Ca2+]i）。
用ATP（0.3 - 3.0 microM）或ADP（0.1 - 1.0 microM）持续灌注可引起单个BAEC中[Ca2+]i的重复振荡。[Ca2+]i振荡的频率取决于核苷酸浓度和施加的剪切应力水平；在核苷酸总体浓度恒定的情况下，频率随剪切应力增加。在激动剂持续存在时停止流动会立即消除振荡反应。去除细胞外Ca2+并不抑制[Ca2+]i振荡。在存在不可水解的核苷酸类似物ATPγS或ADPβS的情况下，施加流动会导致类似的剪切依赖性[Ca2+]i振荡，这表明[Ca2+]i反应的流动调节并非仅仅是由于外核苷酸酶水解核苷酸导致BAEC单层附近的ATP或ADP耗竭。
这些发现表明，局部血液动力学条件可能在体内调节血管活性药物对血管内皮的作用。
