The Effect Of Liquid Petroleum Gas Poisoning On Neurogenesis And Learning And Memory In Mice, And The Intervention Of BFGF

Objective: This study investigated the mechanism of acute liquid petroleum gas (LPG) poisoning impaired the cognitive function of mice, and the effect of intervention and treatment of basic fibroblast growth factor (bFGF).Methods: Adult healthy female Kunming mice of SPF, weight between 25-40g, were randomly divided into 5 groups, the control group (CG), LPG low dosage group (LPG-L), LPG high dosage group (LPG-H), bFGF prevention group (bFGF-P) and bFGF treatment group (bFGF-T), respectively. Use the transparent airtight perspex box made by ourselves for poisoning. Find two plastic bags which volume were 25% and 50% of the box, created the 25% and 50% poisoning environment by extruding the bags which were full of 100% LPG when they were in the box. The poisoning process had been intervened by intraperitoneal injection of bFGF one hour before and after on mice, the CG and LPG groups were NS injected instead. We tested the spatial learning and memory ability of mice through the Morris Water Maze (MWW) training. We used the methods of immunohistochemistry to label the BrdU-positive cells with 5-bromo-2-deoxyuridine and the astrocyte (Ast) with glial fibrillary acidic protein. The number and disposition of BrdU-positive cells and AS in subgranular zone of hippocampal dentate gyrus and subventricular zone of lateral ventricle were detected. To analyze the disparation of measurement data, we used the method of one-way ANOVA. Statistical correlation analysis was performed among the average frequence in MWM test, the number of BrdU-positive cells, and the number of GFAP-positive cells.Results:1. Learning result: the mean escape latency of both the LPG-L and the LPG-H groups was prolonged significantly (P < 0.01), and the result has dose-effectrelationship (P < 0.01); but both groups of bFGF were higher than LPG groups (P < 0.01), and compared with the bFGF-T groups, the ability of bFGF-P was improved (P < 0.01). In the Probe trials, compared with the LPG groups, the mean frequences of the bFGF groups increased remarkably (P < 0.01), and the LPG-H group was lower than the LPG-L group (P < 0.05), the bFGF-P group was higher than the bFGF-T group (P < 0.05).2. Neural proliferation: all groups of LPG had less BrdU-positive cells in SGZ and SVZ than the others groups (P < 0.01), and the LPG-H was less than the LPG-L (P < 0.01), but the number of BrdU-positive cells in SGZ and SVZ of the both bFGF groups were more than the bGHG groups (P < 0.01), and the bFGF-P group was more than the bFGF-T group (P < 0.01).3. GFAP expressing: the number of GFAP-positive cells in DG and SVZ of the poisoning groups and the treatment groups increased notably (P < 0.01); and the LPG-H was more than the LPG-L group (P < 0.01); the number of GFAP-positive cells in DG and SVZ of the both bFGF groups were less than the both groups of LPG (P < 0.01); and the bFGF-P group was less than the bFGF-T group (P < 0.01).4. The result of statistical correlation analysis indicated: BrdU-positive cells have a positive correlation with frequences; GFAP-positive cells have a negative correlation with those (P < 0.05).Conclusion: 1. Acute liquid petroleum gas poisoning could restrain the neurogenesis in DG and SVZ of mice, increase the number of astrocyte, and impaired the ability of learning and memory, the effect of damage was obviously when adding the dosage, there was dose-effectrelationship between them. 2. The bFGF could enhance neurogenesis and improve the ability of learning and memory of mice. The results suggested that bFGF could have the effect of prevention and treatment on LPG poisoning through promoting neurogenesis and repressing the activation of astrocyte.