| Highly enriched populations of olfactory ensheathing cells (OECs) from neonatal rat olfactory bulbs were isolated and cultured in the present study. Fibroblast were eliminated from OEC cultures by arabinosyl cytosine (Ara-c). The OECs were identified by positive immunostaining for nerve growth factor receptor p75 (p75NGFR) and glial fiber acidic protein (GFAP). Upon the models of silicone-tubulization of transected sciatic nerve in the adult rats, OECs and chitin solution were injected into the silicone chamber and compared with SAL group. The lesion, the changes of activity of cholinesterase and acid phosphatase of motor neurons in lateral nucleus of spinal cord anterior horn, the function of axoplasm transportation and nerve conduction, the regeneration of axons and myelin sheath, and the recovery of sciatic nerve function were examined at 7, 14, 30 and 90 days intervals after operation, using Nissl and enzyme histochemistry staining, electrophysiological technique, hydrogen-peroxide oxidoreductase (HRP) retrograde trace method, axon image analysis, and measurement of sciatic function index (SFI). The spinal cord anterior horn of injury side was compared to the correspondence region of spinal cord. The objective is to investigate the protective effect of OECs and chitin on spinal cord neurons, and promotive effect on function recovery after sciatic nerve transaction. The results were as follows: 1．OECs had a clear skeleton and were comprised of either spindly bipolar cells or cells bearing multiple processes oriented on opposite poles. The OECs immunostained positively for p75NGFR and GFAP. By using Ara-c, the number of OEC cells increased to about 1.5 times at 14 days, and the percentage of OECs was reach to 70%.2．The number of surive neurons in lateral of spinal cord anterior horn of rats in experimental groups was higher and larger than that of the control at 7, 14, and 30 days after sciatic nerve transection. The intensity of cholinesterase and acid phosphatase of motor neurons were lower than that of the control at the same days.3． The density of axons in the transect of newborn nerve fibers was larger and the thickness of myelin sheath was thicker than that of the control at 30 and 90 days after sciatic nerve transection.4．The latency (LAT) of compound muscle active potential (CMAP) in the experimental groups was shorter, the conduction velocity (CV) was faster, and the amplitude (AMP) was wider than that of the control at 30 and 90 days after sciatic nerve transection.5．The number of HRP positive reaction neurons in lateral nucleus of spinal cord anterior horn in the experimental groups was larger than that of the control at 30 and 90 days after sciatic nerve transection.6．The figure of SFI showed that the functional recovery in the experimental groups was better than that of the control at every 10 days after sciatic nerve transection. The results suggest that treated with OECs and chitin, the death of neuronsand the changes in activity of enzyme were decreased, the regeneration of axons and myelin sheath, the function of axoplasm transportation and nerve conduction, the recovery of sciatic nerve function index were promoted. It can be concluded that OECs and chitin are capable of protecting motor neurons from death induced by peripheral nerve injury, and of enhancing recovery of nervous function. Besides, nerve squeez method is a usful for the isolation of OECs, the morphologic and immunocytochemical action of cultured cells was consistent with previous report, the method of isolation and culture of OECs from rats olfactory bulbs is simple, easy and effective. |
