Morphological changes of the neural cells after blast injury of spinal cord and neuroprotective effects of sodium β-aescinate in rabbits

Abstract 

Objective

Explosive blast neurotrauma is becoming more and more common not only in the military population but also in civilian life due to the ever-present threat of terrorism and accidents. However, little attention has been offered to the studies associated with blast wave-induced spinal cord injury in the literatures. The purpose of this study is to report a rabbit model of explosive blast injury to the spinal cord, to investigate the histological changes, focusing especially on apoptosis, and to reveal whether β-aescinate (SA) has the neuroprotective effects against the blast injury.

Methods

Adult male New Zealand white rabbits were randomly divided into sham group, experimental group and SA group. All rabbits except the sham group were exposed to the detonation, produced by the blast tube containing 0.7g cyclotrimethylene trinitramine, with the mean peak overpressure of 50.4MP focused on the dorsal surface of T9–T10 level. After evaluation of the neurologic function, spinal cord of the rabbits was removed at 8h, 1, 3, 7,14 or 30 days and the H&E staining, EM examination, DNA gel electrophoresis and TUNEL were progressively performed.

Results

The study demonstrated the occurrence of both necrosis and apoptosis at the lesion site. Moreover, the SA therapy could not only improve the neurologic outcomes (P<0.05) but also reduce the loss of motoneuron and TUNEL-positive rate (P<0.05).

Conclusions

In the rabbit model of explosive blast injury to the spinal cord, the coexistent apoptotic and necrotic changes in cells was confirmed and the SA had neuroprotective effects to the blast injury of the spinal cord in rabbits. This is the first report in which the histological characteristics and drug treatment of the blast injury to the spinal cord is demonstrated.

Keywords: Blast injury, Spinal cord injury, Blast overpressure, Pathomorphology, Apoptosis, Aescinate