Influence Of Different Hypoxic Exposure On Hemocyte And Of Hippocampal Neurogenesis In Rats

Objective: This paper aimed to observe and analyze the influence of differenthypoxic exposure on hemocyte and hippocampual neurogenesis of young rats.Methods:80male SD rats were randomly assigned into control groups (C11，C15) andhypoxic treatment groups. According to different hypoxic exposure times (4,8,12h/d)and oxygen concentration (11%,15%), hypoxic treatment groups were divided (4H11,4H15,8H11,8H15,12H11,12H15). BrdU（50mg/mL）was injected intraperitoneally fromthe3rd day one hour before hypoxic exposure for5days. Then detected the bloodabout red blood cells (RBC), hemoglobin (Hb), lymphocyte, monocyte and neurophilegranulocyte. And the brain sections were detected by immunofluorescence techniquewhich labeled BrdU and NeuN.Results:1.Influence of different hypoxic exposure on hemocyteThe number of RBC of8H11group was significantly lower than4H11groups(P<0.05). There was no difference in the number of RBC of15%oxygenconcentration groups in blood.There was no difference in the number of Hb of11%and15%oxygen concentration groups in blood. The number of lymphocyte of4H11group was significantly lower than C11group(P<0.05);8H11and12H11groups weremuch significantly lower than4H11group (P<0.01). There was no difference in thenumber of lymphocyte of15%oxygen concentration groups in blood. There was nodifference in the number of monocyte of11%and15%oxygen concentration groupsin blood. The number of neutrophil of4H11group was significantly higher than C11group(P<0.05);8H11and12H11groups were very significantly lower than4H11group(P<0.01and P<0.01). There was no difference in the number of neutrophil of15%oxygen concentration groups in blood.2.Influence of different hypoxic exposure on hippocampual neurogenesisThere was no difference on the number of BrdU positive cells (BrdU+) and BrdU/NeuN double-labeled cells (BrdU+/NeuN+) of11%oxygen concentration groups inDG.The percentage of new neurons in regenerative cells (Pneuron)of12H11group wassignificantly higher than C11,4H11groups (P<0.05). There were no difference in thenumbers of BrdU positive cells (BrdU+) and BrdU+/NeuN+double-labeled cells (BrdU+/NeuN+) of15%oxygen concentration groups in DG except that BrdU+/NeuN+of12H15group was lower than8H15group. The percentage of new neurons inregenerative cells Pneuronof12H15group was much significantly lower than4H15,8H15groups (P<0.01).Conclusion:1.Seven consecutive days’11%oxygen concentration hypoxic exposure for4hrs/dpromotes the number of lymphocyte and neutrophil in the blood. Comparison with4hrs/d, the8hrs/d can inhibite RBC, lymphocyte and neutrophil in the blood,12hrs/dcan inhibite the number of lymphocyte and neutrophil in the blood. There is noinfluence on the hemocyte of15%oxygen concentration hypoxic exposure.2.Seven consecutive days’ hypoxic exposure (both11%and15%oxygenconcentration) for4,8hrs/d has no influence on the neurogenesis of DG in young rats.7days’11%oxygen concentration hypoxic exposure for12hrs/d promotes thedifferentiation of NSCs which is on the contrary under the same hypoxic exposuretime of15%oxygen concentration.