Tadalafil attenuates spinal cord injury induced oxidative organ damage in rats

Spinal cord injury (SCI) has been shown to cause systemic inflammatory response syndrome (SIRS) which damages multiple organs due to an influx of inflammatory cells from the circulation. In this study, we evaluated the effect of tadalafil, a phoshodiesterase inhibitor, against spinal cord, kidney and bladder damage in experimental animal model of spinal cord injury. Male Wistar albino rats were divided into sham-operated control, and either vehicle or tadalafil-treated SCI groups. In order to induce SCI, a standard weight-drop method that induced a moderately severe injury (100 g/cm force) at T10, was used. Injured animals were given either 10 mg/kg tadalafil or vehicle 15 minutes post injury and repeated daily for seven days. After decapitation spinal cord, kidney and bladder tissue samples were obtained to examine oxidative tissue injury; malondialdehyde (MDA) and glutathione (GSH) levels, and superoxide dismutase (SOD), myeloperoxidase (MPO) and caspase-3 activities. Tissues were also examined histologically. In the injured animals, MDA levels MPO and caspase-3 activities in tissues were found significantly increased while tadalafil treatment reversed these increases. On the other hand SCI-induced decreases in GSH levels and SOD activities were also reversed with tadalafil treatment. According to the results, tadalafil exerts beneficial effects against SCI-induced oxidative damage in spinal cord and also in remote organs such as kidney and bladder tissues through its antiinflammatory and antioxidant effects.