[Effects of 2, 5-hexanedione on S100β of Schwann cells in rat sciatic nerves]

Abstract

Objective: To investigate the expression of S100β protein and mRNA of Schwann cells(SC) in sciatic nerves of 2, 5-hexanedione(HD) intoxicated rats.

Methods: Nine-week old SPF male Wistar rats were administered at daily dosing of 100 and 300 mg/kg by intraperitoneal injection for continuous 8 weeks(five times every week). Age-matched control rats received an equivalent volume of normal saline. Ten rats in each group were sacrificed and sciatic nerves were excised for S100β determination, with excised sciatic nerves from another three rats for morphological observation through electron microscope. At the end of the exposure, the other 8-week treated animals were allowed to naturally recover for 8 weeks and sciatic nerves were excised at the end of the test. S100β protein contents were determined by immunohistochemistry method, and mRNA expression was observed by real-time quantitative polymerase chain reaction(PCR).

Results: HD intoxication with 300 mg/kg was associated with severe neurological deficits of paralysis in hindlimbs, accompanied with evident movement gait abnormalities for 100 mg/kg dosage. The morphological abnormalities in myelin sheath of sciatic nerves were observed through electron microscope after HD-exposure. The S100β contents in 100 mg/kg and 300 mg/kg groups remained relatively unaffected with 92% and 79% of the control respectively after HD-intoxication, and a increase to 149%(P<0. 05) and 119% after a recovery of 8 weeks was accompanied with. As to S100β mRNA, HD-intoxication was associated with decreased expression to 0. 65(P<0. 05) and 0. 56 times(P<0. 05) of the control, and 1. 46 and 0. 87 times for 8-week recovery individually.

Conclusion: The S100β protein and mRNA levels were influenced by HD exposure, and the result suggested that S100β might be involved in HD-induced peripheral axonopathy.

Keywords: 2, 5-hexanedione; S100β; Schwann cells; rat.