Post-traumatic moderate systemic hypothermia reduces TUNEL positive cells following spinal cord injury in rat

Abstract

Study design: A standardized animal model of contusive spinal cord injury (SCI) with incomplete paraplegia was used to test the hypothesis that moderate systemic hypothermia reduces neural cell death. Terminal deoxynucleotidyl transferase [TdT]-mediated deoxyuridine triphosphate [dUTP] nick-end labeling (TUNEL) staining was used as a marker of apoptosis or cell damage. Objective: To determine whether or not moderate hypothermia could have a neuroprotective effect in neural cell death following spinal cord injury in rats. Setting: Kagawa Medical University, Japan. Methods: Male Sprague-Dawley (SD) rats (n ¼ 39) weighing on average 300 g (280-320 g) were used to prepare SCI models. After receiving contusive injury at T11/12, rats were killed at 24 h, 72 h, or 7 days after injury. The spinal cord was removed en bloc and of examined at five segments: 5 and 10 mm rostral to the center of injury, center of injury, and 5 and 10 mm caudal to the center of injury. Rats that received hypothermia (321C/4 h) were killed at the same time points as those that received normothermia (371C/3 h). The specimens were stained with hematoxylin and eosin, and subjected to in situ nick-end labeling (TUNEL), a specific method for visualizing cell death in the spinal cord. Results: At 24 h postinjury, TUNEL positive cells (TPC) decreased significantly 10 mm rostral to center of injury in hypothermic animals compared to the normothermia group. At 72 h post-SCI, TPC also decreased significantly at 5 mm rostral, and 5 and 10 mm caudal to the lesion center compared to normothermic animals. At 7 days postinjury, a significant decrease of TPC was observed at the 5 mm rostral and 5 mm caudal sites compared to normothermic animals. Conclusion: These results indicate that systemic hypothermia has a neuroprotective effect following SCI by attenuating post-traumatic TPC.

A force plate measurement system to assess hindlimb weight support of spinal cord injured rats

“…This difference in data shows that cooling intervention immediately post-SCI has strong therapeutic effect. This confirms reports by other workers who found that cooling therapy improves recovery after SCI in rats (Shibuya et al, 2004;Morino et al, 2008). It should be stressed that the BBB method can be useful for measuring locomotion, whereas the current force plate method can be useful for measuring postural support.…”

Protection in Animal Models of Brain and Spinal Cord Injury with Mild to Moderate Hypothermia

“…As with necrosis, apoptotic cell death appears to be sensitive to postinjury hypothermic treatment strategies. Using terminal deoxynucleotidetransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining, DNA fragmentation has been found to be reduced by hypothermia in severe TBI (Brodhun et al, 2001), transient global ischemia (Zhang et al, 2001b), transient focal ischemia (Inamasu et al, 2000a;Phanithi et al, 2000;Prakasa Babu et al, 2000), and SCI (Shibuya et al, 2004). Levels of caspase 3, an important initiator of apoptotic cell death, are highly sensitive to hypothermic treatment (Phanithi et al, 2000;Van Hemelrijck et al, 2005;Lotocki et al, 2006), as is cytochrome c release Zhao et al, 2004Zhao et al, , 2005Zhao et al, , 2007.…”

Glial and axonal regeneration following spinal cord injury

“…By varying the compression time from 10 to 30 min, it is possible to produce models of different severity from mild incomplete paralysis to complete paralysis. 8 Process of functional recovery. After complete spinal cord transection in cats and rats, the occurrence of bilaterally symmetrical locomotive activities in the hindlimbs (walking-like neural activity) is a well known observation.…”