Time course of superoxide generation in reperfusion after arterial ischaemia and venous congestion

Salvage of free second toe with venous thrombosis by shunting retrograde arterial flow of second dorsal metatarsal artery

Although there are case reports about salvaging amputated digits without venous return by shunting retrograde blood flow from a distal digital artery to a proximal vein (Smith et al., Plast Reconstr Surg 71:52, 1983), successful salvage of a congested free toe with efferent arteriovenous (AV) shunting retrograde arterial flow from the second dorsal metatarsal artery (SDMA) has never been reported. In this paper, we describe the possible factors for venous thrombosis, the errors we committed in the operation, and how the free toe can survive without venous drainage.

Changes in nitric oxide, superoxide, and blood circulation in muscles over time after warm ischaemic reperfusion in rabbit rectus femoris muscle

We present the sequence of changes in nitric oxide (NO) and superoxide (O2-) over time in reperfusion injuries. We examined both the changes in NO and O2- over time and the blood flow in an isolated ischaemia-reperfusion muscle model in rabbits. The ischaemic group comprised 8 animals which had had vascular pedicles clamped on the their rectus femoris muscles for 4 hours. The control group (n = 6) had a sham operation. Blood samples from the femoral vein proximal to the clamping point were collected before the operation, before clamping, before reperfusion, immediately after reperfusion, and 5, 15, 30, 60, and 120 minutes after reperfusion. NO was measured by Griess' method, and O2- by chemiluminescence. Blood flow was measured with a laser Doppler flowmeter. The amount of NO increased significantly immediately after reperfusion, and 15 and 30 minutes after reperfusion in the ischaemic group, compared with the control group (p < 0.05). O2- increased significantly at 5, 15, 60, 90 and 120 minutes after reperfusion, compared with the control group (p < 0.05). The blood flow volume curve increased by 1.4 times about four minutes after reperfusion compared with previously. After this it gradually decreased. The adverse effects of O2- became apparent when NO was extinguished by O2-.

Time course of superoxide anion radicals generation in two ischaemia-reperfusion models: comparison between hindlimb replant model and isolated rectus femoris muscle model

We examined differences in superoxide radical (O(2)(-)) production between a hindlimb replant model and isolated rectus femoris muscle model using rabbits. Using Japanese white rabbit hindlimbs, we made limb replant models (LR group: n = 10) and isolated rectus femoris muscle models (IM group: n = 8) by temporary 4-h clampings of femoral vessels and nutrient vessels, respectively. For sham control subjects, the same surgical procedures with no clampings in both models were done (Control-LR: n = 7, Control-IM: n = 6). The measurement of O(2)(-)was performed by our chemiluminescence (CLN) method. In both models, reperfused blood samples were collected before reperfusion, and 5, 15, 30 and 60 min after reperfusion, and CLN was measured. We defined the superoxide index (SI) in each individual specimen as post-reperfusion CLN/pre-reperfusion CLN. The time course of SI in the Control-LR group was significantly higher than that of SI in the Control-IM group (P< 0.05). There was no significant difference between the time course of SI in the LR group and that of SI in the IM group. Both the limb replant model and isolated muscle model are applicable for the evaluation of radical formation in the reperfused stage though there are potential differences between the two models caused by the surgical procedures themselves.