Relation of phospholipase A2-V and indoxam to hippocampal neuronal death

Fang Liu; Shi Wang; Yan Lin; Runhui Li; Li Ma; Yanjun Li; Qing Jin; Xiao Gong; Yuhua Chen

摘要：BACKGROUND: V secretory phospholipase A2 (sPLA2- V ) is abundant in many mammal tissues. However, it remains unknown whether sPLA2-V causes biological or pathological response in central nervous system.OBJECTIVE: To observe the effect of phospholipase A2- V (PLA2- V ) and its inhibitor (indoxam) on hippocampal neuron survival.DESIGN: A repetitive measurement.SETTING: The Animal Center of South Carolina University.MATERIALS: Sprague-Dawley pregnancy day-7, 14, 21 female rats were selected; Reagents: sPLA2- V and indoxam were obtained from the Dennis Research Laboratories METHODS: The experiment was finished at the animal center in South Carolina University from January to December, 2004. 0, 12.5, 25, 50 and 100 μg/L sPLA2-V were added to neuron with none-MgCl2 Eagle's medium at 37 ℃, then changed to normal neuron culture medium after 3 hours. 1, 2.5, 5 and 10 μmol/L indoxam was added at 6 hours after 100 μg/L sPLA2-V was put to Day-21 SD rat hippocampal embryonic neurons with none-MgCl2 Eagle's medium at 37 ℃. After 3 hours in the inhibition experiment, it was changed to normal neuron culture medium. The embryonic hippocampal neurons were primarily cultured, and the neuron survival ratio was detected with morphological method.MAIN OUTCOME MEASURES: Survival ratio of hippocampal neurons.RESULTS: ① Effects of sPLA2-V on neuron survival: When sPLA2-V was 0, 12.5, 25, 50 and 100 μg/L, the neuron survival ratios in embryonic neurons of day-7 SD rats were (95.3±1.1)%, (81.4±3.1)%, (74.2±2.2)%,(62.4±1.7)% and (48.9±1.6)%, those in embryonic neurons of day-14 rats were (93.2±1.4)%, (74.3±1.9)%,(68.1± 1.7)%, (56.1± 1.4)% and (42.5± 1.1)%, and those in embryonic neurons of day-21 rats were (91.2±1.2)%,(69.4±2.1)%, (60.3±2.2)%, (49.1 ± 1.2)% and (35.5± 1.9)%. There were significant differences among difierent concentrations (P＜ 0.05). ② Effects of indoxam on neuron survival: In case of sPLA2-V 100 μg/L, the neuron survival ratios were (58.65±1.4)%, (69.34±1.1)%, (82.11 ±1.2)% and (95.28±0.9)% when indoxam was 1, 2.5, 5and 10 μmol/L, respectively. There were significant differences among different concentrations (P＜ 0.05).CONCLUSION: ① The of neuronal death ratio is in a concentration-dependent manner with sPLA2- V, and increases as the embryonic aging. ② Indoxam inhibits the proapoptotic effect of sPLA2-V.