“Three Methods and Three Points” regulates p38 mitogen-activated protein kinase in the dorsal horn of the spinal cord in a rat model of sciatic nerve injury

Tuina is a traditional Chinese treatment for sensory disturbances caused by peripheral nerve injury and related diseases. Our previous studies showed that tuina regulates relevant regions and indices of the spinal dorsal horn using the Dian, Bo, and Rou method in Yinmen（BL37）, Yanglingquan（GB34）, and Weizhong（BL40）. Treatment prevents muscle atrophy, protects spinal cord neurons, and promotes sciatic nerve repair. The mechanisms of action of tuina for treating peripheral nerve injury remain poorly understood. This study established rat models of sciatic nerve injury using the crushing method. Rats received Chinese tuina in accordance with the principle of ＂Three Methods and Three Points,＂ once daily for 20 days. Tuina intervention reduced paw withdrawal latency and improved wet weight of the gastrocnemius muscle, as well as promoting morphological recovery of sciatic nerve fibers, Schwann cells, and axons. The protein expression levels of phospho-p38 mitogen-activated protein kinase, tumor necrosis factor-α, and interleukin-1β also decreased. These findings indicate that ＂Three Methods and Three Points＂ promoted morphological recovery and improved behavior of rats with peripheral nerve injury.

Neuroprotective effect of recombinant human erythropoietin on optic nerve injury in rats

Background Optic nerve injury, caused by retinal and optic nerve diseases, can eventually result in vision loss. To date, few effective treatments have been discovered to restore visual function. Previous studies showed that recombinant human erythropoietin （rhEPO） has a neuroprotective effect on the central nervous system, particularly in nerve injury. In this study, we investigated the effects of rhEPO on axonal regeneration and functional restoration following optic nerve injury. This was done by measuring the expression of growth associated protein 43 （GAP-43）, a marker for neuronal regeneration, on the retina and flash-visual evoked potential （F-VEP）. Methods Adult Wistar rats were randomly assigned to rhEPO and control （saline） groups. Optic nerve crush injury models were established and rhEPO or saline were immediately injected into the vitreous cavity. The expression of GAP-43 was detected by immunohistochemistry and the F-VEP was measured pre-injury, immediately after injury, 1 week and 2 weeks post-injury. Results No detectable staining for GAP-43 was observed in normal retina. In the control group, the level of GAP-43 expression was higher at 1 week post-injury, but decreased at 2 weeks. In the rhEPO group, the level of GAP-43 expression was notably higher at both 1 week and 2 weeks. At each time point post-injury, the expression of GAP-43 in rhEPO group was significantly higher than the control group （P 〈0.05）. Obvious changes in F-VEP examination were detected immediately after optic nerve injury, including significantly prolonged latency and decreased amplitude of the P1 wave. In the control group, the changes were still obvious at 1 week. The latency was decreased and the amplitude had slightly recovered to 28.23% of the normal value at 2 weeks. In rhEPO group, there was significantly more recovery than the control group at 1 week and 2 weeks post-injury （P 〈0.05）. The latency most close to the normal level and the amplitude had recovered to 65.51% of the normal value at 2 weeks. Conclusions rhEPO can prolong the expression of GAP-43 and increase its intensity after optic nerve injury, thereby promoting neural repair and axonal regeneration. Under the protection of rhEPO, the conduction velocity of the optic nerve recovered significantly. Therefore, rhEPO has neuroprotective effects on the optic nerve and promotes functional restoration of the optic nerve. Chin Med J 2009;122（17）：2008-2012