[The protective effect of propofol pretreatment on glutamate injury of neonatal rat brain slices].

OBJECTIVE: To study the protective effect of propofol precondition against glutamate (Glu) neurotoxicity to neonatal rat cerebrocortical slices. METHODS: Brain slices of Sprague-Dawley (SD) rats were cultured in vitro and observed the morphologic changes. Brain slices were randomly divided into three groups: blank control group, Glu injury group (1 mmol/L Glu for 0.5 hour), propofol precondition group (20 mg/L propofol for 24 hours), each n=12. Changes in pathological and ultra-structure of cells were observed using microscope. Lactate dehydrogenase (LDH) leakage rate was measured. Meanwhile, the expression of glial fibrillary acidic protein (GFAP) was detected by immunohistochemical technology, then the positive cell were counted. RESULTS: Cultured brain slices of cell were intact and survived well. Hematoxylin-eosin (HE) staining, electron microscopy and LDH test results showed that cerebral film neuron severely damage, gliosis, edema, LDH leakage rate in Glu injury group were significantly more severe compared with blank control group [(68.5±2.0)% vs. (16.0±2.5)%, P<0.01]. Reduce the brain slice of the propofol pretreatment group of neuronal cell jury, cell shape recovery significantly reduced LDH leakage rate compared with the Glu injury group [(38.5±2.4)% vs. (68.5±2.0)%, P<0.05]. Immunohistochemical detection of GFAP expression of Glu injury group glial cell body swelling, producing increase in the number of GFAP positive reaction strong, the number of positive cells compared with blank control group was significantly increased (50±5 cells/HP vs. 10±3 cells/HP, P<0.01). The recovery of propofol pretreatment group glial cell morphology, cell processes slender GFAP positive reaction decreased the number of positive cells compared with the Glu injury group was significantly decreased (30±4 cells/HP vs. 50±5 cells/HP, P<0.05). CONCLUSION: Propofol pretreatment has protective effect against Glu injured rat cerebrocortical slices.

[A comparative study on the protection effect of nerve growth factor and edaravone pretreatment against cerebral ischemia/reperfusion injury].

OBJECTIVE: To compare the protective effect of nerve growth factor (NGF) and edaravone (a free radical scavenger) pretreatment against cerebral ischemia/reperfusion (I/R) injury to nerve cells. METHODS: Cortical neurons of Sprague-Dawley (SD) mouse aged shorter than 24 hours were cultured for 7 days, then they were randomly divided into control group, I/R group, NGF of 10, 50, 100 microg/L pretreatment groups and 100 mumol/L edaravone pretreatment group. In pretreatment groups the cells were pretreated with drugs correspondingly. After culturing for 24 hours, glutamate of 200 mumol/L was given into the culture of all groups, except control group, for half an hour. Then culture medium in all groups were renewed with ordinary culture medium, and cultures were continued for 24 hours. The survival rate (by methyl thiazolyl tetrazolium assay), the content of lactate dehydrogenase (LDH, by spectrometry) and the rate of apoptosis (by flow cytometric) were determined. The cellular shape and ultrastructure were observed by hematoxylin-eosin (HE) staining and electronic microscopy correspondingly. RESULTS: The survival rate of nerve cells in NGF groups and edaravone group was significantly higher than that in I/R group [(0.21 + or - 0.04)%, (0.23 + or - 0.04)%, (0.21 + or - 0.04)%, (0.24 + or - 0.04)% vs. (0.19 + or - 0.04)%]. The content of LDH in culture medium and the rate of apoptosis in NGF groups and edaravone group were lower than those in I/R group (P<0.05 or P<0.01). The release rate of LDH in each group was (0.50 + or - 0.06)%, (0.46 + or - 0.07)%, (0.50 + or - 0.02)%, (0.43 + or - 0.06)% vs. (0.56 + or - 0.03)%, respectively. The rate of apoptosis in each group was (10.77 + or - 1.07)%, (10.38 + or - 0.70)%, (13.34 + or - 0.57)%, (9.99 + or - 0.77)% vs. (14.52 + or - 0.77)%, respectively. The cellular shape and ultrastructure of nerve cells in NGF groups and edaravone group were affected much less than that of I/R group. NGF of 50 microg/L pretreatment group gave the best effect among three groups. There was no significant difference between NGF 50 microg/L pretreatment group and edaravone pretreatment group. CONCLUSION: NGF and edaravone pretreatment 24 hours before cerebral I/R give protective effects against cerebral I/R injury. The protective effects are best in NGF of 50 microg/L pretreatment group and edaravone pretreatment group, and there is no significant difference between them.