Expression and significance of expression of ?-endorphin in hippocampus after HPM radiation in rat / 解放军医学杂志

ABSTRACT

Objective To investigate the expression and significance of ?-endorphin in hippocampus after high power microwave (HPM) radiation. Methods 50 male Wistar rats were sacrificed at 6h, 1d, 3d, 7d, 14d, 28 days after exposure to 12mW/cm~2 HPM imitational source radiation. The hippocampus was harvested, the characteristics of injury to the hippocampus and expression of ?-endorphin were evaluated by means of light microscope, EM, immunohistochemistry and image analysis. Results In the neutrons of hippocampus, mitochondrial swelling and myelin sheath confluence and dissociation were observed 6 hours after radiation, and mitochondrial swelling, cavitation, disruption of crista, concentration margining of chromatin, blurring of synaptic cleft, piling or evacuation of vesicles were observed 3 days after HPM radiation. The expression of ?-endorphin in cytoplasm of neurons was up-regulated continuously from 1 to 7 days, peaking at 7 days, restoring to normal level from 14 to 28 days after radiation. Conclusion HPM can produce injury to the hippocampus at histological and ultrastructural levels. The expression of ?-endorphin is up-regulated, and it might play an important role in the pathophysiological process of injury and repair in the hippocampus.