Reactive hyperaemia in the hind limbs of rabbits.

Reactive hyperaemia was measured with electromagnetic flowmetry of the terminal aorta in rabbits. The aorta was occluded just above the bifurcation for periods from 10 seconds to 5 minutes. Maximal flow and recovery time of reactive hyperaemia increased significantly with increasing periods of circulatory arrest. Percentual repayment was higher after brief occlusions (10-30 seconds) than after long occlusions (1-5 minutes), when a percentual repayment of about 40% was found. A slight decrease of ascending aortic flow was observed when reactive hyperaemia was induced in the hind limbs. Several mechanisms may play a part in reactive hyperaemia, and the relative importance of the different mechanisms may vary with the length of occlusion.