TITLE:
Effects of Methylprednisolone on the Expression and Activity of Calpain Following Ischemia-Reperfusion Spinal Cord Injury in Rats
AUTHORS:
Zifeng Zhang, Jinquan Xu, Yushu Bai, Tiesheng Hou
KEYWORDS:
Methylprednisolone; Spinal Cord Injury; Ischemia-Reperfusion Injury; Calpain
JOURNAL NAME:
Neuroscience and Medicine,
Vol.5 No.1,
March
7,
2014
ABSTRACT: The present study was undertaken to examine the
effects of methylprednisolone on the expression and activity of calpain in
spinal cord tissue following spinal cord ischemia-reperfusion injury in rats.
Adult male Sprague-Dawley rats were subjected to sham operations,
ischemia-reperfusion and vehicle treated, or ischemia-reperfusion with
methylprednisolone administration after injury. The expression of calpain I in
the injured segments of the spinal cord as well as the degradation of the 68 kD
neurofilament protein (NFP), a calpain-specific substrate, was determined at 3 h, 24 h,
72 h and 7 days after reperfusion using immunohistochemical labeling and
western blot analysis, respectively. Three hours after spinal cord reperfusion,
calpain I-positive cells and NFP degradation products were evident. The number
of positive cells and immunoreactivity increased with time and peaked at 72 h
after reperfusion. In addition, the number of calpain I-positive cells and the
abundance of NFP degradation products were significantly lower in the
methylprednisolone group, compared with vehicle treated animals following
ischemia-reperfusion injury. The results of this study suggest that
methylprednisolone can inhibit the expression and degradation activity of
calpain following ischemia-reperfusion injury, providing further insight into
the therapeutic benefits of methylprednisolone treatment for spinal cord
injury.