Protective Effects And Effect On Neuroglobin Expression Of Potentilla Anserina L. To Hypobaric Hypoxia In Rats

Objective: To establish the model of hypobaric hypoxia injury (HHI), and to study the protective effects and effect on Neuroglobin (Ngb) expression of Potentilla anserina L. to hypobaric hypoxia in Rats.Methods: Male Sprague-Dawley Rats were randomly divided into control group, model group, intervention groups of Potentilla anserina L. alcohol extract (3.6g/kg, 1.8g/kg, 0.9g/kg). After 14 days intragastric administration continually, all the groups without the control were underwent 12 hours -0.06Mpa hypobaric hypoxia in decompression chamber. Evaluate the morphological changes of cardiac muscles, cerebra and kidney after HHI by H.E stain. The effect of different dose Potentilla anserina L. alcohol extract on cerebral HHI in rats were studied by detecting the water concentration in brain, observing the changes of ultrastructure in neurons by transmission electron microscope, and detecting the biochemical indicators (ET-1, CGRP) by ELISA. The expression levels of Ngb were studied by RT-PCR and Western Blot in brain. The expression localization of Ngb in neurons was investigated by immuno-histochemistry stain. Results: 1 The protective effect of Potentilla anserina L. alcohol extract on HHI in rats: (1) The morphological changes of neurons, cardiac muscles and kidney by H.E stain: The morphological changes of cardiac muscles: In model group, the myofibrils arranged disorderly, and waved injury, the infiltration of inflammatory cells were observed. In intervention group of Potentilla anserina L. alcohol extract (3.6g/kg), the cardiac muscles were better protected. In hippocampus CA1 to CA4 of model group, the main character of neurocytes was cellular necrosis and apoptosis. A lot of dead cells with axonotmesis and disappearance.The main character of neurons in cortex of parietal lobe was cellular swelling that cyton swelled, nucleus inflated or disappeared, cytoplasm stained light. In intervention groups of Potentilla anserina L. alcohol extract (3.6g/kg, 1.8g/kg), the neurons were better protected, and the morphous of neurons was more integrity. The morphological changes of kidney: In model group, remarkable hyalinization in epithelial cell of renal tubule. In intervention group of Potentilla anserina L. alcohol extract (3.6g/k), the hyalinization was light. (2) The change of ultrastructure in the neurons: in the control group, the nuclear membrane was integrity and lampros, electron-lucent of karyotin was low. The nucleuses were in good condition. The structure of mitochondrion was completed. In intervention groups of Potentilla anserine L.alcohol extract (3.6g/kg), the nucleuses were better protected, and the damage degree of mitochondrion and nuclear membrane were light. (3) The water concentration in brain: Compared to control group (68.04±0.6%), the model group (75.05±3.6%) was distinguished increased (P<0.01), but the groups of Potentilla anserine L.alcohol extract (3.6g/kg) were reduced (P<0.01). (4)ELISA experimentation (ET-1, CGRP): The contents of serumal ET-1 in model group was higher than in control group (P<0.01), and the ratio of ET-1/CGRP was raised in model group. In the groups of Potentilla anserine L.alcohol extract (3.6g/kg, 1.8g/kg, 0.9g/kg), the contents of serumal ET-1 was decreased obviously(P<0.01). Compared to in control group, the difference of the ET-1/CGRP ratio in Potentilla anserine L.alcohol extract (3.6g/kg) was little.2 Effects on change of Ngb expression of Potentilla anserina L. alcohol extract after HHI in brain: (1)Immuno-histochemistry stain: Compared to model group(P<0.01), Potentilla anserine L.alcohol extract(3.6g/kg, 1.8g/kg) stimulated the expression levels of Ngb in cortex neurons after HHI. In hippocampus CA1-CA2 , Potentilla anserine L.alcohol extract(3.6g/kg) stimulated a few of Ngb expressions, but no in control and model groups. (2) Western Blot: Compared to control group, the expression of Ngb in the model group was increased (P<0.01). Potentilla anserine L.alcohol extract (3.6g/kg) promoted the expression levels of Ngb remarkablely (P<0.01). (3) RT-PCR: the result was similar to Western Blot.Conclusion: After HHI, Potentilla anserina L. alcohol extract could relieve the damage degree of neurons, cardiac muscles and nephros; depress the degree of ultramicrostructure changes; relieve the cerebral edema; reduce the release of ET-1, stimulate the release of CGRP, and keep the dynamic balance between ET-1 and CGRP. Potentilla anserina L. alcohol extract could promote the release of Ngb mRNA as well as Ngb.