The Experiment Study Of The Role Of Neuregulin1 In N-Hexane-Induced Rat's Myelin Sheath Damage

Objectives To investigate the role of Neuregulin1 in n-Hexane-Induced myelin sheath damage in rats.Methods 27 SD rats(SPF grade) were randomly divided into control group, low dose group and high dose group after adaptive feeding for a week. The rats in control group were intraperitoneal injected into the same volume saline. Rats in low dose group and high dose group were respectively received 200 mg/kg and 400 mg/kg of 2,5-hexanedione by intraperitoneal injection. Every other day performed the measures during continuous 6 weeks. Neurobehavioral tests were applied to detect rats' motor and sensory nerve behavioral changes. transmission electron microscope were used to observe sciatic nerve cross-sections ultrastructural changes of myelin sheath. Location of NRG1 in cerebellum, pons, spinal cord and sciatic nerve tissue were observed by immunohistochemistry. The levels of NRG1 in those four parts were determined by Western Blot.Results Compared with control group, the weight of rats in low dose group and high dose group were reduced 12.2% and 14.4% in the 6 week, and the differences were significant. Compared with control group,residence time in the hot plate in low dose group and high dose group were increased 29.2% and 65.8%, the resident time of the rats' tail in hot water in high dose group were increased 38.0%, and the farthest distance of rats' both sides extended in high dose group were increased 20.1%, the differences were significant. Electron microscopy results showed that myelin sheaths were loose and appear to vesicaes in the low dose group as well as the plate were separated in high dose group. Immunohistochemistry results revealed that NRG1 expression in such parts: neurons in cerebellar granular layer, the lateral department of spinal cord, pons and Schwann cells in the sciatic nerve. Compared with control dose group, NRG1 were expressed in cerebellum, spinal cord, pons, and sciatic nerve tissue of low dose group and high dose group, and were respectively reduced 18.3%,64.4%;22.9%,51.3%;45.8%,473.3%;109.1% and 475.0%(P<0.05). Compared with low dose group, the expression of NRG1 were reduced 38.9%,23.1%,293.3% and 175.0%, and the differences were significant.Conclusions N-Hexane exposure resulted in the expression of NRG1 were decreased markedly. The high dose group were more significant than low dose group. Different the expression of NRG1 were in different nerve tissues, the more in cerebellar and pons as well as the less in spinal cord and sciatic nerve. All parts of nerve tissues were decreased, particularly in sciatic nerve, which was decreased dramatically and was damaged badly. It might relate to n-Hexane-induced myelin sheath damage.