Neuroprotective effects of progesterone in spinal cord ischemia in rabbits.

Background: This experimental study was performed to investigate the neuroprotective effects of progesterone on spinal cord ischemia in rabbits.

Methods: Eighteen female New Zealand white rabbits were used in this study. Rabbits were randomized into 3 groups. Spinal cord ischemia was induced by clamping the abdominal aorta from a point just inferior to the left renal artery to the aortic bifurcation for a period of 30 minutes. Group 1 served as the control group, and groups 2 and 3 received intraperitoneal progesterone immediately after the onset of reperfusion, at a dose of 8 mg/kg. Two hours after reperfusion, the animals in group 1 were killed. Four hours after reperfusion, the animals in group 2 were killed, and 6 hours after reperfusion, the group 3 rabbits were killed. Spinal cords were removed and fixed in 10% formalin in a phosphate buffer. Neuronal injury was evaluated by a pathologist who was blinded to the treatment groups, and 5 sections per animal were evaluated. The number of intact large motor neuron cells in the ventral grey matter region was counted.

Results: The analysis revealed that the average mean arterial pressure for group 1 was significantly higher than that for group 2, and the mean sacrificed pressure value for group 1 was significantly higher than that for group 3 (P < .05). The number of intact neurons in group 1 was significantly lower than the number of intact neurons found in both groups 2 and 3 (P < .05). No other statistically significant differences were found between the groups.

Conclusion: The findings from the present study indicate that progesterone effectively protects the spinal cord tissues against ischemic damage in the setting of decreased perfusion.