Microcirculation of the Bulbar Conjunctiva in the Goat Implanted with a Total Artificial Heart: Effects of Pulsatile and Nonpulsatile Flow
Microcirculation of the Bulbar Conjunctiva in the Goat Implanted with a Total Artificial Heart: Effects of Pulsatile and Nonpulsatile Flow
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DOI：
10.1097/01.mat.0000129320.57362.db
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发表时间：
2004-07
期刊：
影响因子：
4.2
通讯作者：
A. Baba;P. Dobsak;I. Saito;T. Isoyama;K. Takiura;Y. Abe;T. Chinzei;J. Vašků;K. Imachi
中科院分区：
文献类型：
--
作者：
A. Baba;P. Dobsak;I. Saito;T. Isoyama;K. Takiura;Y. Abe;T. Chinzei;J. Vašků;K. Imachi
为研究人工心脏（total artificial heart，TAH）内血流模式对微循环的影响，建立了一套利用数字化高清晰度显微镜观察球结膜微循环的新系统。将波动泵TAH植入山羊体内。当全身状况稳定后，在搏动和非搏动模式之间调节流型，观察微循环的变化。当血流模式由脉动流转为非脉动流时，红细胞在毛细血管中的流速由526 ± 83 μm/s降至132 ± 41 μm/s，并维持在较低水平。灌注毛细血管的数量也减少。然后维持非脉动流模式20分钟。当血流模式再次恢复到脉动模式后，红细胞流速恢复到初始水平（433 ± 71 μm/s）。在许多情况下，在非搏动模式下的非灌注毛细血管的流量恢复到初始水平后，流动模式再次改变为搏动模式。非搏动模式下的灌注毛细血管密度（19.7 ± 4.1个毛细血管/mm）显著低于搏动模式（34.7 ± 6.3个毛细管/mm）据认为，由于脉动性的消失，微血管中的基础和流动刺激的内皮源性一氧化氮释放减少，并且一氧化氮诱导微血管的收缩。血流模式改变为非搏动模式后的小动脉。同时，压力感受器可感觉到动脉峰压或dp/dt的降低，交感神经增强活动，引起小动脉收缩。红细胞在毛细血管中的运动速度降低。由于在慢性期的流动模式进一步，重要的是要遵循微循环的变化。
A new system to observe the microcirculation on the bulbar conjunctiva was developed using a digital high definition microscope to investigate the influence of the flow patterns on the microcirculation in a goat with a total artificial heart (TAH). The undulation pump TAH was implanted into the goat. When the whole body condition became stable, the flow pattern was modulated between the pulsatile and the nonpulsatile mode, and the changes in the microcirculation were observed. When the flow pattern was changed from pulsatile to nonpulsatile mode, the erythrocyte velocity in capillaries dropped from 526 ± 83 to 132 ± 41 μm/s and remained at a low level. The number of perfused capillaries decreased as well. Then the nonpulsatile flow mode was maintained for 20 minutes. After the flow pattern was returned to the pulsatile mode again, the erythrocyte velocity recovered to the initial level (433 ± 71 μm/s). In many cases, the flow of the nonperfused capillaries in the nonpulsatile mode recovered to the initial level after the flow pattern was changed to the pulsatile mode again. The perfused capillary density in the nonpulsatile mode (19.7 ± 4.1 number of capillaries/mm ) was significantly lower than that in the pulsatile mode (34.7 ± 6.3 number of capillaries/mm ).It is thought that the basal and flow stimulated endothelium derived nitric oxide release in the microvessels decreased because of the disappearance of pulsatility and that the nitric oxide induced the constriction of arterioles after the flow pattern was changed to the nonpulsatile mode. At the same time, the baroceptors might sense the decrease in the arterial peak pressure or dp/dt, and the sympathetic nerve increases activities and induce the constriction of arterioles. Then, the erythrocyte velocity in capillaries would decrease. Because of the flow pattern further in the chronic phase, it is important to follow the change in the microcirculation.