Enhancement of the post-occlusive oscillation in the splenic circulation by adenosine.

1. The blood flow to the splenic artery of dogs anaesthetized with sodium pentobarbitone was measured under constant pressure perfusion with the animal's own blood led from the femoral artery.2. Immediately after release of occlusion there was a rapid increase of inflow rate above the pre-occlusion level which then oscillated up and down. In a majority of cases such oscillatory responses continued for a while but progressively diminished during a period of about 6 min.3. This post-occlusive oscillatory response was not modified by either neural or autonomic receptor blocking agents such as tetrodotoxin, guanethidine, phentolamine, propranolol, atropine and methysergide.4. In the cases with a relatively short-lasting response, the selective administration of adenosine into the splenic artery caused a distinct enhancement of the oscillation.5. These results suggest that adenosine may play an important role in the post-occlusive oscillatory response of the splenic circulation.