[Protective effect of adenosine preconditioning against spinal cord ischemia-reperfusion injury in rats]

To study the effect of adenosine preconditioning on cell apoptosis and expressions of glucose-regulated protein (GRP-78) and cysteinyl aspartate-specific protease 12 (caspase-12) in rats with spinal cord ischemia-reperfusion injury.

Twenty-seven rats were randomized into 3 equal groups and subjected to sham operation (group A), spinal cord ischemia-reperfusion injury (group B), or ischemia-reperfusion injury with adenosine treatment. Spinal cord ischemia-reperfusion injury was induced by cross-clamping of the abdominal aorta inferior to the left renal artery. The spinal cord function was assessed using the Modified Tarlov Scale at 6, 12, and 24 h after reperfusion. At 24 h after reperfusion, histological analysis was carried out with HE staining; cell apoptosis and viability were determined with TUNEL staining, and the expressions of GRP-78 and caspase-12 proteins were determined with Western blotting.

HE staining of the spinal cord showed extensive spinal cord injury such as cell edema in group B as compared with group C. Compared with group A, group B showed a significantly increased number of apoptotic cells; the number of apoptotic cells in group B was greater than that in group C. Compared with group B, group C showed significantly increased GRP-78 expression (P<0.01) and decreased caspase-12 expression (P<0.01).

Adenosine can up-regulate GRP-78 expression and down-regulate caspase-12 expression, and protects the spinal cord against ischemia-reperfusion injury by inhibiting cell apoptosis.