Abstract
We measured articular blood flow by standard microsphere techniques in normal adult dogs at rest and during treadmill exercise. All animals but one underwent ฮฒโadrenergic blockade as part of another experimental protocol. Expressed in ฮผl/min/g ยฑ SEM, baseline flow values to articular tissues were: knee synovium 26 ยฑ 4, femoral condyle 130 ยฑ 21, tibial plateau 182 ยฑ 29, articular fat pad 9 ยฑ 2, knee ligaments 17 ยฑ 3, menisci 34 ยฑ 6, wirst synovium 19 ยฑ 4, distal radius 65 ยฑ 13, and lunate bone 59 ยฑ 13. Blood flow increased with exercise in all soft tissue of both the knee (stifle joint) and the wrist (radiocarpal joint). Geometric mean exercise/rest flow ratios ranged from a low of 1.44 (p < 0.05) in the menisci of the knee to a high of 7.25 (p < 0.001) in the synovium of the wirst. In contrast, blood flow did not rise in juxtaarticular bones and fell significantly in femoral condyles (mean flow ratio 0.71, p < 0.005). These findings indicate that articular soft tissues derive increased perfusion from the redistribution of blood flow that accompanies shortโterm exercise. In contrast, flow to juxtaarticular bone does not increase under these conditions.