Protective effect of sildenafil (Viagra) in transient spinal cord ischemia

Prospective study of the neuroprotective activity of sildenafil in a rat spinal ischemia model. The present study involved 21 male Sprague-Dawley rats. The animals were divided into 3 groups. Physiological serum was administered intraperitoneally to the 8 rats in the control group at the beginning of reperfusion for a period of 20 min after abdominal aortal occlusion. Sildenafil (Viagra) was administered as a single 10-mg/kg/day intraperitoneal dose to the 8 rats in the sildenafil group at the beginning of reperfusion after 20 min of abdominal aortal occlusion. No occlusion was performed and no agent was administered to the 5 rats in the sham group, but the abdominal aorta was reached by means of surgical intervention. Before the animals were sacrificed, several physiological and biochemical parameters were investigated, preoperative and postoperative motor functions were also assessed, and somatosensory evoked potential (SEP) monitoring and histopathological examinations were carried out. No differences were found between the physiological and biochemical parameters in each of the 3 groups. Neurological scoring performed after reperfusion demonstrated a significant improvement in the neurological results relative to those of the control group over 48 h in subjects that received sildenafil. These animals also showed better 24-hour SEP results, measured in terms of extended latency and decreased amplitude, than the control animals. A histopathological study showed reduced ischemic symptoms in rats that received sildenafil compared with those in the control group. However, no anomalies were observed in the sham group with respect to the histopathological and neurological findings. These results indicate that neurological damage due to spinal-cord ischemia-reperfusion injury can be reduced by sildenafil.