Abstract:

Objective To explore the effect of Tuina of Three Handing-Three Points on the recovery of motor function, the expression of neuregulin (NRG) 1 and human epidermal growth factor receptor (ErbB) 2 in the injured point of sciatic nerve and L_4-6 spinal cord, and the morphological change of myelin sheath at the injured point of sciatic nerve of rats.Methods A total of 76 male Sprague-Dawley rats were randomly divided into normal group, sham operation group, model group and Tuina group with 19 rats in each group. The right side sciatic nerve was clamped to make model in the model group and Tuina group. The sham operation group exposed sciatic nerve only. Tuina group received Tuina on Yinmen (BL37), Chengshan (BL57) and Yanglingquan (GB34) with dialing, plucking and kneading using Tuina technique simulator. All of them were tested with Oblique Plate Test before modeling, seven days and 28 days after modeling. Western blotting was used to detect the protein expression of NRG1 and ErbB2 in the injured point of sciatic nerve and L_4-6 spinal cord. The change of myelin sheath at the sciatic nerve injury point was observed and analyzed by transmission electron microscope.Results Seven days and 28 days after modeling, the scores of Oblique Plate Test were lower in the model group and Tuina group than in the normal group and the sham operation group (P< 0.05); 28 days after modeling, the scores was higher in Tuina group than in the model group (P< 0.05). At the sciatic nerve injury point, three days after modeling, the expression of NRG1 and ErbB2 was higher in the model group and Tuina group than in the normal group and the sham operation group (P< 0.05); seven days and 28 days after modeling, there was no significant difference in NRG1 among groups (P> 0.05); 28 days after modeling, the expression of ErbB2 was higher in the model group and Tuina group than in the normal group and the sham operation group (P< 0.05). In L_4-6 spinal cord, three days after modeling, the expression of NRG1 and ErbB2 was higher in the model group and Tuina group than in the normal group and sham operation group (P< 0.05); seven days after modeling, the expression of NRG1 was higher in the model group and Tuina group than in the sham operation group (P< 0.05), and the expression of ErbB2 was higher in the model group and Tuina group than in the normal group and the sham operation group (P< 0.05); 28 days after modeling, the expression of NRG1 was higher in Tuina group than in the model group (P < 0.05), and there was no significant difference in ErbB2 among groups ( P> 0.05). The electron microscope showed that, 28 days after modeling, the myelin sheath collapsed seriously in the model group; while the ultrastructure of the nerve injury point improved, and the myelin sheath of the nerve fiber was relatively intact in Tuina group; the g-ratio value was lower in the model group than in the sham operation group (P< 0.05), the g-ratio value was higher in Tuina group than in the model group (P< 0.05), and no difference was found in g-ratio value between Tuina group and sham operation group (P> 0.05).Conclusion Three Handing-Three Points could improve the motor function of hind limbs in rats with sciatic nerve injury, which may be related to the adjustment of NRG1 and ErbB2 in the sciatic nerve and spinal cord, to maintain normal myelin sheath structure.

Key words: sciatic nerve clamping injury, myelin sheath, neuregulin 1, human epidermal growth factor receptor 2, Tuina, rats