Mayer, Daniela; Oevermann, Anna; Seuberlich, Torsten; Vandevelde, Marc; Casanova, Ayako; Selimovic-Hamza, Senija; Forterre, Franck; Henke, Diana (2016). Endothelin-1 Immunoreactivity and its Association with Intramedullary Hemorrhage and Myelomalacia in Naturally Occurring Disk Extrusion in Dogs. Journal of veterinary internal medicine, 30(4), pp. 1099-1111. Wiley-Blackwell 10.1111/jvim.14364
|
Text
endothelin.pdf - Published Version Available under License Creative Commons: Attribution-Noncommercial (CC-BY-NC). Download (1MB) | Preview |
BACKGROUND:
The pathophysiology of ascending/descending myelomalacia (ADMM) after canine intervertebral disk (IVD) extrusion remains poorly understood. Vasoactive molecules might contribute.
HYPOTHESIS/OBJECTIVES:
To investigate the immunoreactivity of endothelin-1 (ET-1) in the uninjured and injured spinal cord of dogs and its potential association with intramedullary hemorrhage and extension of myelomalacia.
ANIMALS:
Eleven normal control and 34 dogs with thoracolumbar IVD extrusion.
METHODS:
Spinal cord tissue of dogs retrospectively selected from our histopathologic database was examined histologically at the level of the extrusion (center) and in segments remote from the center. Endothelin-1 immunoreactivity was examined immunohistochemically and by in situ hybridization. Associations between the immunoreactivity for ET-1 and the severity of intramedullary hemorrhage or the extension of myelomalacia were examined.
RESULTS:
Endothelin-1 was expressed by astrocytes, macrophages, and neurons and only rarely by endothelial cells in all dogs. At the center, ET-1 immunoreactivity was significantly higher in astrocytes (median score 4.02) and lower in neurons (3.21) than in control dogs (3.0 and 4.54) (P < .001; P = .004) irrespective of the grade of hemorrhage or myelomalacia. In both astrocytes and neurons, there was a higher ET-1 immunoreactivity in spinal cord regions remote from the center (4.58 and 4.15) than in the center itself (P = .013; P = .001). ET-1 mRNA was present in nearly all neurons with variable intensity, but not in astrocytes.
CONCLUSION AND CLINICAL IMPORTANCE:
Enhanced ET-1 immunoreactivity over multiple spinal cord segments after IVD extrusion might play a role in the pathogenesis of ADMM. More effective quantitative techniques are required.