Effect Of Ischemic Burden On Intrinsic Femoral Artery Collateral Circulation In Rabbits

Objective: To explore the isometric exercise induced ischemic burden for evoking maximal intrinsic femoral artery collateral circulation.Methods: Twenty-four adult New Zealand rabbits (2.0±0.5kg) were subjected to the model of isometric contraction induced ischemia. The electrode was implanted to sciatic nerve of left hind limb for evoking isometric contraction which blocked local blood flow and induced local ischemia. Femoral artery collateral blood flow (FCBF) was measured by microspheres technique.Results:①Local blood flow was the lowest at the 40% maximal isometric exercise (IEmax) and reached plateau at the 60% IEmax.②FCBF increased gradually and reached plateau with 40% IEmax at the 4th min (P < 0.01).③FCBF after 4 min stimulus at the 40% IEmax increased higher than the value of pre-stimulus and reached the peak at the 2nd min (P<0.01), and then decreased gradually to the baseline at the 5th min after reperfusion, which ceased to increase with the reperfusion prolonging to 8min or 10min.Conclusion: The results suggest that the minimal ischemic burden for full obstruction of femoral artery is 40% IEmax with minimal 4 min. The maximal opening is no more than 5 min.