Cerebral Microvascular and Systemic Effects Following Intravenous Administration of the Perfluorocarbon Emulsion Perftoran
AIM To investigate the anti-ischemic properties of perfluorochemical emulsion "perftoran" in mesenteric region. METHODS Experiments were conducted on 146 nonlinear white male rats weighing 200-350 g. Partial critical intestinal ischemia was induced by thorough atraumatic strangulation of 5-6 cm jejunal loop with its mesentery for 90 min. Global critical intestinal ischemia was made by atraumatic occlusion of the cranial mesenteric artery (CMA) for 90 min also. Perftoran (PF, 0.8-1.0 mL per 100 g) in experimental groups or 0.9% sodium chloride in control groups was injected at 75 min of ischemic period. Mean systemic arterial blood pressure (BP(M)) registration, intravital microscopy and morphological examination of ischemic intestine and its mesentery were performed in both groups. RESULTS During 90 min of reperfusion, BP(M) progressively decreased to 27.3+/-7.4% after PF administration vs 38.6+/-8.0% in the control group of rats with partial intestinal ischemia (NS) and to 50.3+/-6.9% vs 53.1+/-5.8% in rats after global ischemia (NS). During the reperfusion period, full restoration of microcirculation was never registered; parts with restored blood flow had leukocyte and erythrocyte stasis and intra-vascular clotting, a typical "non-reflow" phenomenon. The reduction of mesenteric 50-400 mum feeding artery diameter was significantly less in the PF group than in the control group (24+/-5.5% vs 45.2+/-3.6%, P<0.05) 5 min after partial intestinal ischemia. This decrease progressed but differences between groups minimized at the 90(th) min of reperfusion (41.5+/-4.2% and 50.3+/-2.8%, respectively). In reperfusion of rat's intestine, a significant mucosal alteration was registered. Villous height decreased 2.5-3 times and the quantity of crypts decreased more than twice. In the group of rats administered PF, intestinal mucosal layer was protected from irreversible post-ischemic derangement during reperfusion. Saved cryptal epithelial cells were the source of regeneration of the epithelium, which began to cover renewing intestinal villi after 24 h of blood flow restoration. View of morphological alterations was more heterogeneous in CMA groups. CONCLUSION Systemic administration of perftoran promotes earlier and more complete structural regeneration during reperfusion in rats after partial and global critical intestinal ischemia.