Synchrotron Radiation Imaging Reveals the Role of Estrogen in Promoting Angiogenesis After Acute Spinal Cord Injury in Rats

Study Design. The efficacy of estrogen on vessel angiogenesis in acute spinal cord injury (SCI) in a rat model was evaluated by synchrotron radiation. Objective. Here, we investigate the change in injured spinal cord vessels and used the synchrotron radiation to investigate the effect of estrogen on vessel angiogenesis and functional recovery in a rat model of SCI. Summary of Background Data. The promotion of angiogenesis after SCI may be a therapeutic target in the treatment of SCI. Estrogen has been reported to improve locomotor recovery after SCI. However, how estrogen regulates angiogenesis in acute SCI and enhances neurological functional recovery has not been fully characterized. Methods. Synchrotron radiation imaging combined with histological methods was used to image angiogenesis in acute spinal cord treatment with estrogen in rats. Results. Synchrotron radiation imaging vividly demonstrated three-dimensional vessel changes in the spinal cord after injury. The imaging showed that vessel number, vessel volume fraction, and vessel connectivity value in the groups treated with estrogen after SCI were significantly increased compared to control groups (P<0.05). Vessel angiogenesis increased in groups treated with estrogen compared with control rats, which was confirmed with histological staining. Estrogen treatment also attenuated the injury-induced lesion area compared with control groups and improved locomotor functional recovery after SCI. Conclusion. The results indicated that synchrotron radiation is a powerful imaging tool for visualizing angiogenesis after acute SCI. Estrogen treatment exerted a neuroprotective effect on acute SCI treatment by promoting angiogenesis and reducing the injury-induced lesion area could be recommended as a potential preclinical treatment approach for acute SCI.