The Protective Effects Of The Invariable Magnetic Field On The Oxidative Injured Schwann Cell

Purpose: For many years, the pathological changes of peripheral nerve affect thepeople's living quality badly, which is a very important and complicate process in neural system diseases. Recently, researchers found that one of the pathogenesis is that oxidative irritation can make free radical increase, which cause the apoptosis of Schwann cells. Schwann cell is a glial cell of peripheral nerve system, which can wrap the axon to form myelinated nerve fiber or nonmyelinated nerve fiber. It can secrete many kinds of neurotrophic factors which are concerned with development and regeneration of nerve. Recently, more and more people apply external assists: such as neurotrophic factor, Chinese traditional medicine, electromagnetism, silica gel and other grafts to enhance schwann cells' function, then to cure the peripheral nerve injuries.Ancient and modern, many materials prove that the magnetic field has effects of treating disease and corroborating body. Modern medical investigation indicates that the function of the magnetic field is mainly influencing the lipoid fluid membrane of the cells and the concordant integration between the cells. The magnetic field has a lot of function in medical field, for example: static magnetic therapeutics, multiple magnetic therapeutics, magnetic water, and so on. The magnetic therapeutics has a great deal of excellence, for instance the operation easily, taking effect quickly, little side-effect etal. It can be used to cure many kinds of diseases, such as dysmenorrhea, cervical syndrome, epilepsy, lunacy, glaucoma, cataract, hypertension, migraine and so forth. The magnetic therapeutics can boost hyperplasia of the capillary vessel, enhance the growth of epidermis, accelerate concrescence of ulcers, and adjust the action of the blood vessel and improve the circulation of blood of heart diseases. Magnetic water can increase the osmosis of cells, enhance the action of digestive enzymes, increase digestive action, restrain the forming concretion and dissolve the formed concretion. Magnetic water can also cure cystic concretion, pancreatic concretion and urinary concretion.There are many kinds of magnetic fields. According to the relation of magnetic field and time, there are invariable magnetic field and variable magnetic field. The invariable magnetic field is the most simple and basic magnetic field, which is fit for the basic investigation. There are much development on different levels such as the animal body, apparatus, cell, molecule and so on. Today, the magnetic therapeutics has been used widely; however the mechanism of the invariable magnetic field protecting Schwann cell impaired by oxidation has not been reported.The investigation is aimed at probing into the antioxidant and protecting function of the invariable magnetic field (4mT).The oxidization-damaged Schwann cells model induced by the peroxide hydrogen is used to investigate the mechanism of the invariable magnetic field. Simultaneously, we offered the theoretical proofs for the invariable magnetic field to cure the neuropathy of peripheral nerve.Method: In this subject, we chosen sciatic nerves and brachial nerves of neonatalWistar rat younger than 72 hours as experiment materials. They are cultured in liquid-DMEM/F12 containing 10% of the fetal calf serum under 5% CO₂,37°C, saturated humidity. The Schwann cells cultured 24 hours were divided into several groups.1. Preparation of the invariable magnetic field(4mT):Two magnets are laid up and down, and laid in the cultivation case of 5% CO2,37° C,saturated humidity ahead of schedule.2. Purify and identify Schwann cells: Adding Ara-c in order to get rid of fibroblast-like cells. After cultivating 3d we identified the cultured cells and calculated the purity of Schwann cells by the immunohistochemistry staining (S-100 antibody is used). 3. Treating by the invariable magnetic field or oxidization damage: There were three cultured groups: one group was oxidization-damaged group treated with hydrogen whose final concentration was 0.5%,another was treated with peroxide hydrogen(0.5% H₂O₂) and the invariable magnetic field(4mT),and another was control group only treated with culture liquid.4. Investigating Schwann cells activity of different groups by MTT assay.5. Measuring endocellular MDA and SOD by biochemistry assay.6. Measuring Caspase-3 by immunohistochemistry assay.Through above experiments, we set up the oxidization-damaged Schwann cells model induced by hydrogen dioxide, and probed into the anti-oxidant protective action of the invariable magnetic field (4mT) at the same time.Result: Primary Schwann cells were round, suspending in the medium whenin-oculated at once. Most cells attached after 6 hours, and most cells began to turn into oval-shape. After 24 hours, the cells were dipolar with a power fulscene of three-dimension and satiation and were shuttle-shape with two or three slender dendrites. After cultured 48-72 hours, there were polymerize that a lot of Schwann cells grew in group arranging end to end, side by side and palisade; the cells were assembled into pile called "cellular island". After cultured24 hours, Ara-c(the concentration of Ara-c in the medium was 10^-5mol/L) was added into the medium and removed after 48-72 hours, we observed that the purity was increased obviously under light microscope, and immunohistochemis- try(S-lOO) staining showed that more than 80% of the cells presented positive reaction. 12 hours after adding H₂O₂,we observed the change of the cellular shape under microscope: the dendrites withered, the cells swelled into roundness, the quantity of Schwann cells reduced, some cells took off the wall and floated in the culture liquid, the cells' three-dimensional scene was bad and refraction dropped, a large number of cell piece were obvious. But under the protection of the invariable magnetic field, all cells were growing well with a powerful sceneof three-dimension and the cells were scarcely withered and broken, but it wasobserved that the cell gathered obviously. In the control group, the cells' growing station was well.The evaluation of different factor-treated groups was following:1.Analyzing antioxidant function of the invariable magnetic field by MTT indicates: The invariable magnetic field can obviously resist the oxidization induced by the peroxide hydrogen. Compared with the hydrogen damaged group, there is a higher cellular livability in the invariable magnetic field treated group. There is statistical significance between them (P<0.05), but there is not statistical significance between normal-control group and invariable magnetic field group.2. Biochemical measure indicates: Compared with the damaged group, the invariable magnetic field kept the endocellular superoxide dismutase (SOD) in high level. It was obvious that the invariable magnetic field resisted SOD reducing caused by the peroxide hydrogen though this level was lower than the control group. Both had statistics significance (P<0.05).3. Compared with the normal control group, the peroxide hydrogen caused lipid-hydrogen piled up inside the cells, but the invariable magnetic field obviously reduced this kind of pileup (P<0.05). In the normal control group there was less endocellular lipid peroxide.4. Measuring Caspase-3 by immunohistochemistry: It was powerfully positive in the hydrogen peroxide-damaged group, weakly positive in the invariable magnetic field-protected group, and there was nearly dyeing negative in the normal control group.Conclusion: We made the peroxide hydrogen-damaged Schwann cells model withthe primary cultured Schwann cells. From the investigation we discovered that the invariable magnetic field resisted the oxidization damage induced by the peroxide hydrogen visibly. The peroxide hydrogen caused that the endocellular free radical increased, and the lipid activity of SOD reduced and the endocellular lipid-hydrogen increased. The increased free radicals resulted finally apoptosis through Caspase-3 pathway. However, the invariable magnetic field can reduce the content of endocellular lipid hydrogen-MDA, maintain the higher level of SOD and reduce the concentration of Caspase-3 to avoid the failure incident.These results showed that the invariable magnetic field's function protecting the Schwann cells by resisting the oxidization damage and the antioxidant molecular mechanism through the signal pathway of the oxidization damage. And it analyzed and confirmed the way in which the invariable magnetic field resisted the oxidization damage for the first time, provided the theoretical foundations for the invariable magnetic field to cure the neuropathy of peripheral nerves.