Effects of ketamine and dexmedetomidine on ischemia- reperfusion injury in an experimental renal ischemia model.

Kidneys are one of the organs most affected by ischemia-reperfusion (I/R) injury during surgical interventions. The present study aimed to investigate the effects of ketamine and dexmedetomidine administered in a rat model of renal I/R injury prior to ischemia. A total of 24 male Sprague-Dawley rats were included in the present study and divided into four groups. The Sham group underwent laparotomy and right nephrectomy, while the other groups underwent laparotomy, right nephrectomy and 45 min of ischemia to the left kidney, followed by reperfusion for 24 h. No medication was administered to the I/R group. The Ketamine group received 2 mg/kg intraperitoneal ketamine prior to ischemia. The Dexmedetomidine group received an initial dose of 1.0 mcg/kg dexmedetomidine intravenously over 10 min before ischemia, followed by a continuous infusion of 1.0 mcg/kg/h during the operation. Blood was drawn for serum creatinine level measurements before the operation and at sacrifice. Renal samples were taken for histopathological examination right before the rats were sacrificed. The final creatinine measurements of the I/R and Ketamine groups were higher compared with those of the Sham group (P=0.012 and P=0.001, respectively). The final creatinine measurements of the Dexmedetomidine group were lower compared with those of the Ketamine group (P=0.040). In addition, measurements of tubular dilation (P=0.002 and P=0.001, respectively), vacuolization in tubular epithelium (P=0.002 and P=0.003, respectively) and loss of brush border in tubular epithelium (P=0.008 and P=0.001, respectively) were significantly higher in the I/R and Ketamine groups compared with the Sham group, while there was no significant difference between the Dexmedetomidine group and the Sham group. Measurements in the Dexmedetomidine group were lower compared with the I/R group, but the difference was not statistically significant. Despite a reduction in serum creatinine levels and histopathological injury scores in subjects treated with dexmedetomidine compared with the I/R group, the differences were not found to be statistically significant. By contrast, the Ketamine group demonstrated significantly higher serum creatinine levels and histopathological injury scores compared with both the I/R and Dexmedetomidine groups. These findings suggested that dexmedetomidine may be associated with more favorable biochemical and histopathological outcomes compared with ketamine in the present experimental model of renal I/R injury; however, further studies are needed to validate these findings.