Conclusions
Our results showed that intravenously administered RIPCs remarkably improved the neuropathic pain symptoms, thermal hyperalgesia and mechanical allodynia. Further studies are needed to evaluate the role of RIPCs transfusion on glial cells.
Methods
The sciatic nerve partial ligation method was used to induce neuropathic pain. Changes in neuropathic pain symptoms were assessed by measuring thermal hyperalgesia and mechanical allodynia. To determine the possible therapeutic site, alterations in the number of spinal cord lumbar posterior horn microglia and astrocytes were evaluated by ionized calcium-binding adapter molecule 1 (iba1) and glial fibrillary acidic protein (GFAP) immunostaining. Myelin basic protein immunohistochemistry was also used to assess Schwann cell immunoreactivity in the sciatic nerve.
Results
In rats that underwent partial sciatic nerve ligation, neuropathic pain symptoms developed on average on day 12 and persisted up to day 21 (p < 0.0001). RIPCs administered intravenously for five days reduced thermal hyperalgesia more than intraperitoneal and subcutaneous administration (p < 0.05). Both central glial cells appear to play a role in the effect of RIPCs. RIPCs treatment increases Schwann cell remyelination. Conclusions: Our results showed that intravenously administered RIPCs remarkably improved the neuropathic pain symptoms, thermal hyperalgesia and mechanical allodynia. Further studies are needed to evaluate the role of RIPCs transfusion on glial cells.