Effects of tadalafil—Type-V phosphodiesterase enzyme inhibitor—On rats with spinal trauma

Abstract

In this research, the effect of tadalafil, a selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5, on rats with spinal trauma was evaluated. The evaluation consisted of neurological examination and biochemical parameters. Twenty healthy male Wistar albino rats were used in this study. They were separated into three groups: tadalafil-receiving (TD) group (n = 7), laminectomy and trauma (LT) group (n = 7), and just laminectomy group (n = 6). The TD group received daily dose of tadalafil (10 mg/kg) for a week along with bait and water. Each rat's spinal cord was dissected with utter caution. The spinal cord was traumatized by Allen's weight-drop method. Using a standard apparatus, 5 g of weight was dropped from a height of 10 cm on the spinal cords of the TD and LT (laminectomy + trauma) group. No extra maneuvers were conducted on the laminectomy group. A day later, the rat's functional neurological status was examined followed by re-exploration of the spinal cord for sampling 1 cm of tissue. The Tarlov scale was used to evaluate the functional neurological status. The modified Tarlov scale was rated to be significantly higher in the TD group than that in the LT group. For the biochemical parameters, malondialdehyde (MDA) and cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) involved in the inflammatory process were examined. MDA—an indicator of lipid peroxidation—was found to be significantly lower in the TD group compared with that in the LT group. TNF-α and IL-6 levels were also found to be lower in the TD group compared with those in the LT group. Shortly, this research showed that the use of TD group in spinal trauma resulted in better neurological outcome and significant improvement in biochemical parameters.

Keywords::

• neuroprotection
• secondary injury
• spinal cord injury
• tadalafil
• tarlov scale

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.