ABSTRACT
<p><b>OBJECTIVE</b>To establish a stable and modified mouse model of brain death (BD) and to share our experiences in BD induction and maintenance.</p><p><b>METHODS</b>Totally 35 C57BL/6 male mice were randomized into BD group (n=25) or sham control group (n=10). BD was induced by inserting a 2F Fogarty catheter connected to a syringe pump after trepanation of the left frontoparietal area and injecting volume at the speed of 6 μl/min until spontaneous respiration ceased. BD was diagnosed by electroencephalogram, apnea testing,as well as testing of brain stem reflexes. Mechanical ventilation was performed by orotracheal intubation. Right carotid artery was intubated by a PE-10 cannula for the continuous monitoring of mean blood pressure (MAP) and heart rate (HR). The right external jugular vein was catheterized for volume resuscitation.The sham control group underwent the same procedure with catheter insertion but without balloon inflation.Livers were removed and fixed in paraffin to evaluate the histological alterations with the light microscopy.</p><p><b>RESULTS</b>Mouse models of BD were successfully established about 20 minutes after balloon inflation, and the mean balloon volume at the time of BD was (105.77 ± 21.57)μl. The MAP and HR rapidly increased on occurrence of BD and the peak value was (128.28 ± 17.16) mmHg and (434.16 ± 55.75) beat/min, respectively, which were significant higher than those in the sham control group at the same time point (P=0.000). During the 4-hour follow-up time, MAP and HR in 72% (18/25) of BD animals remained haemodynamically stable. No animal died due to anesthesia and surgical operation.Hepatic tissues in BD mice showed mild focal ischemic damages (cellular edema, congestion, and inflammatory infiltration), which were slighter and fewer in sham control group.</p><p><b>CONCLUSION</b>The mouse model of BD was successfully established with lower surgical difficulty and can be performed in a standardized, reproducible and successful way.</p>
Subject(s)
Animals , Male , Mice , Brain Death , Disease Models, Animal , Heart Rate , Intracranial Pressure , Mice, Inbred C57BLABSTRACT
<p><b>OBJECTIVE</b>To observe the hemodynamic change and reperfusion injury cause by transient hepatic venous occlusion and transient hepatic inflow occlusion in rats.</p><p><b>METHODS</b>The rat liver was divided into 3 different areas: the ischemia reperfusion (IR) area: the inflow of the right superior lobe was clamped for half an hour; the non-isolated lobe congestive reperfusion (NIL-CR) area: the outflow of the right median lobe was clamped for half an hour; and the isolated lobe congestive reperfusion (IL-CR) area: the outflow of the left lobe was clamped for half an hour. The flux value and the oxygen saturation of microcirculation were monitored before at clamping for 30 minutes, and on 1 day, 3 days ,and 7 days after reperfusion. The hepatic damage and Suzuki's score were evaluated.</p><p><b>RESULTS</b>After clamping for 30 minutes, the flux value in the IR area was significantly higher than in NIL-CR area (P<0.01) and IL-CR area (P<0.01), the oxygen saturation in the IR area was significantly higher than in NIL-CR area (P<0.01) and IL-CR area (P<0.05). Compared with IR area, both NIL-CR area and IL-CR area were found having more severe liver damage in terms of Suzuki's score in early postoperative period (at clamping for 30 minutes and on 1 day, P<0.01). However, there was no significant difference between NIL-CR area and IL-CR area in flux value, oxygen saturation, and Suzuki's score (P>0.05).</p><p><b>CONCLUSIONS</b>Hepatic venous occlusion can more effectively decrease the blood perfrusion and oxygen saturation; thus, compared to the IR, CR can result in more severe liver damage. The presence of normal liver tissue around the congestion area can not influence liver damage in transient hepatic venous occlusion.</p>