大鼠失血性休克时软脑膜微循环的动态变化

作者观察了不同程度的失血性休克对大鼠软脑膜微循环的影响,以及在一定低血压下微循环障碍的变化规律。实验结果表明,当血压降至3.2 kPa(24 mmHg)时,可造成微循环的明显障碍。早期以充血为主,表现为微动脉扩张或微动脉的节段性扩张与收缩,毛细血管网充血开放数目增多,流态维持在O～1级。持续90min以后,微血管逐渐收缩,红细胞聚集加重,流态逐渐过渡到2～3级;晚期呈现出微循环的严重缺血状态。

DYNAMIC CHANGES OF PIAL-MICROCIRCULATION IN RATS DURING HEMORRHAGIC SHOCK

The influence of shock in varied degrees on pial-microcirculation in rats and the dynamic change of pial-microcirculation in hypotension were observed. It was shown that severe disturbance occurred in pial-microcirculation when blood ressure was lowered to 3.20 kPa.In early stage after severe bleeding the main manifestation of pial-microcirculatory disturbance was hyperemia, i. e., dilatation of arteriole or segmental dilatation-contraction of arteriole, hyperemia of capillary net, increased number of opened capillaries and appearance of 0-I degree of blood flow status (according to the classification of Tia Niu).Ninety minutes after bleeding arterioles and venules became gradually constricted,red blood cells aggregation was increased, ischemia of pial-microcirculation became more severe and blood flow status changed from 1st to 2nd, even 3rd degree.The results demonstrate that autoregulation of cerebral microcirculation is much stronger than that of other organs. Microcirculatory disturbance does not appear until blood pressure drops to the degree beyond the ability of autoregulation.