Myhre H O
Acta Chir Scand. 1975;141(7):609-14.
The effect of increased circulatory fluid volume and local venous congestion on reactive hyperaemia was studied in the hind limbs of rabbits. Compared with controls, hypervolemia reduced maximal flow significantly after all occlusion times. Percentual repayment decreased after 10 second occlusions, increased above control level after 60 second occlusions, and otherwise was similar to controls. Hypervolemia increased recovery time significantly after occlusions longer than 10 seconds. It is possible that decreased oxygen carrying capacity of the blood due to decreased haematocrit after infusion can explain the increased repayment observed during hypervolemia. Furthermore, oedema formation may to some extent prolong the wash-out of metabolites in the postischaemic period. During venous congestion, maximal flow, percentual repayment as well as recovery time were significantly reduced after all occlusion times. Venous congestion may represent an increased resistance against blood arriving from the arterial side after release of the arterial occlusion, thereby reducing the initial part of reactive hyperaemia and perhaps a major part of the hyperaemia after short occlusions. In addition the congested blood may represent an increased amount of oxygen made available for the tissue, and finally venoarterial reflexes may contribute to the reduction of reactive hyperaemia during venous congestion. These results show that factors such as circulatory blood volume and venous pressure and blood volume of the local vascular bed affect reactive hyperaemia significantly.
在兔后肢研究了循环血容量增加和局部静脉充血对反应性充血的影响。与对照组相比，血容量过多在所有阻断时间后均显著降低最大血流量。在阻断10秒后，百分比偿还量降低，在阻断60秒后高于对照水平，其他方面与对照组相似。在阻断超过10秒后，血容量过多显著延长恢复时间。输注后由于血细胞比容降低导致血液携氧能力下降，这可能解释了血容量过多时观察到的偿还量增加。此外，水肿形成可能在一定程度上延长缺血后代谢产物的清除时间。在静脉充血期间，在所有阻断时间后最大血流量、百分比偿还量以及恢复时间均显著降低。静脉充血可能代表在动脉阻断解除后对来自动脉侧的血液的阻力增加，从而减少反应性充血的初始部分，也许还减少短时间阻断后充血的主要部分。此外，充血的血液可能代表为组织提供的氧量增加，最后静脉-动脉反射可能有助于在静脉充血期间减少反应性充血。这些结果表明，诸如循环血容量、静脉压力和局部血管床血容量等因素会显著影响反应性充血。
