The effect of isometric contraction in opening femoral artery collateral circulation in rabbits / 中华物理医学与康复杂志

ABSTRACT

Objective To explore the effect of isometric contraction-induced ischemic burden for evoking maximal intrinsic femoral artery collateral circulation. Methods Twenty-four adult New Zealand rabbits weighing (2.0±0.5) kg were subjected to a model of isometric contraction-induced ischemia. An electrode was implanted in the sciatic nerve of the left hind limb for evoking isometric contraction of the gastrocnemius, which blocked local blood flow and induced local ischemia. Femoral artery collateral blood flow (FCBF) was measured using a micro-sphere technique. Results Local blood flow was the lowest at 40% of the maximal isometric contraction (IEmax), and reached plateau at 60% of IEmax. FCBF increased gradually and reached a plateau at 40% of IEmax in the 4th min. After 4 minutes at 40% of IEmax, FCBF had increased to higher than pre-stimulus, peaking in the 2nd minute, and then decreasing gradually to baseline at the 5th minute after reperfusion. It ceased to increase when reperfusion was prolonged to 8 or 10 min. Conclusions The minimal ischemic burden for full obstruction of the femoral artery is 40% of IEmax, and the shortest stimulus duration is 4 min. The maximal FCBF opening duration is no more than 5 min.