Effects Of Magnetic Field On Wound Healing Of Rabbit Ears

Objectives By observing the differences of the pathologic changes and testing the expression of PPAR-β, type I and III collagen fibers, TNF-α and IL-6of inflammatory cytokines in wound tissues during the progress of wound healing, to establish the experimental evidence supporting the theory that magnetic field promotes wound healing.Methods Animal models of wounds utilizing rabbit ears were established.2000gauss magnetic field was applied to the test group (left sides, L), while nothing to the control group (right sides, R). The wound healing time is observed and the wound tissues are collected at2,6hours and1,3,7,21days after trauma. Pathologic changes of tissues were observed by HE stain in optical microscope. The expression of type I and Ⅲ collagen fibers and the expression of TNF-α and IL-6of inflammatory cytokines were tested by immunohistochemistry. The expression of PPAR-P mRNA and protein were tested by Real-time PCR and Western blot. And the test indexes between the test group and the control group mentioned above were compared.Results The results of HE stain showed that inflammatory cells were observed in all groups, and the infiltration of inflammatory cells in the control group was more significant. The results of immunohistochemistry showed that the expression levels of type Ⅰ collagen fibers in the test group at7d,21d were lower than in the control group(P<0.05) and both reached the peak at3d, the expression levels of type Ⅲ collagen fibers in the test group at2h,6h, Id,3d were higher than in the control group(P<0.05) and both reached the peak at3d, the ratio of the expression levels of type Ⅰ and Ⅲ collagen fibers in the test group were obviously lower than in the control group at the late phase of wound healing, the expression levels of TNF-α and IL-6of inflammatory cytokines in the test group were at a low level all the time and lower than in the control group(P<0.05) while the expression levels in the control group reached the peak at3d. The results of Real-time PCR and Western blot showed that the expression levels of PPAR-β mRNA and protein in the test group at2h,6h,1d,3d were higher than in the control group(P<0.05) and both reached the peak at3d.Conclusions1. Magnetic field can up-regulate the expression of PPAR-β and type Ⅲ collagen fibers at the early phase of wound healing, and can promote the progress of early wound healing.2. Magnetic field can inhibit inflammatory cells aggregation and the production of TNF-α and IL-6of inflammatory cytokines during the progress of wound healing, and can reduce local inflammatory reaction and offer good conditions to wound healing.3. Magnetic field can down-regulate the expression of type I collagen fibers and inhibit the production of TNF-a and IL-6of inflammatory cytokines at the late phase of wound healing and after, this possibly play a role of inhibition for scar formation after wound healing.