The effects of inosine on clinical and histological findings after experimental spinal cord injury in rats

Inosine is a naturally occurring purine nucleoside, the effect of which was discovered only in recent decades. It has potential to prevent neuronal and glial death and can stimulate axonal outgrowth. This study evaluated the effect of inosine (400 mg per rat) administered orally two hours after experimental spinal cord injury and continuously daily for 12 days. We observed the effect of inosine on clinical and histological changes by means of measurement of recovery of hind leg motor function and urinary bladder function, frequency of spasms, neuronal profile and spinal cord tissue sparing. The rats were randomly divided into three groups, SCI-Aqua and SCI-Inosine, with daily administration of aqua for injection or inosine, and SCI-Sham group without spinal injury. The motor function of hind legs and urinary bladder function were evaluated daily for 12 days after the spinal cord injury. In the SCI-Inosine group we recorded lower incidence of spasms due to spinal cord irritation in the early postoperative period when compared to the SCI-Aqua group. We used immunohistochemistry with specific neuronal antibodies to determine the neuronal profiles and the Luxol fast blue staining method to detect the white and grey matter tissue sparing. In our study we recorded significant differences in recovery between the SCI-Aqua and SCI-Inosine group from eighth days after surgery. Moreover, the post mortem investigation of transverse spinal cord sections revealed significantly higher numbers in the SCI-Inosine group (more neurons, greater tissue sparing). According to our findings inosine accelerates the recovery of neurological functions.