[Effect of propofol on myelin basic protein expression and myelination of oligodendrocytes in neonatal SD rats].

OBJECTIVE: To investigate the effects of different doses of propofol on myelin basic protein (MBP) synthesis and myelination of oligodendrocytes in neonatal SD rats. METHODS: A total of 57 neonatal SD rats (7 days old) were randomly divided into control group (n=13), vehicle (fat emulsion) group (n=5), and 25, 50 and 100 mg/kg propofol groups (n=13 in each group). Eight hours after a single intraperitoneal injection of propofol or the vehicle, the rats were examined for expressions of mbp mRNA, caspase-3 mRNA, cleaved caspase-3 and MBP in the brain tissues using qPCR and Western blotting. Immunofluorescence assay was used to detect the apoptosis of the oligodendrocytes at 8 h after the injection and the myelination of the corpus callosum and internal capsule at 24 h. RESULTS: Compared with the control group, the neonatal rats with propofol injections showed significantly down-regulated expressions of mbp mRNA and MBP protein in the brain tissue (P < 0.05). Propofol dose-dependently increased the transcription level of caspase-3 and the protein levels of cleaved caspase-3 at 8 h after the injection (P < 0.05). Propofol injection significantly increased the apoptosis of the oligodendrocytes, and the effect was significantly stronger in 50 and 100 mg/kg groups than in 25 mg/kg group (P < 0.05). At 24 h after propofol injection, myelin formation was significantly decreased in the corpus callosum of the neonatal rats in 100 mg/kg propofol group and in the internal capsule in 50 and 100 mg/kg groups (P < 0.05). CONCLUSIONS: In neonatal SD rats, propofol can dose-dependently promote oligodendrocyte apoptosis, decrease MBP expressions in the brain, and suppress myelin formation in the corpus callosum and the internal capsule.