The increase of reactive oxygen species and their inhibition in an isolated guinea pig spinal cord compression model

Abstract

Study design:In vitro studies using isolated guinea pig spinal cord. Objectives: To develop an alternative model using isolated guinea pig spinal cord, which can be used to screen antioxidants for in vivo SCI treatment. Setting: Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, USA. Methods: The compression injury was induced by a constant-displacement of 5-s compression of spinal cord using a modi®ed forceps possessing a spacer. Reactive oxygen species (ROS) were evaluated using three distinct methods:¯uorescence microscopy, lipid peroxidation assay, and¯ow cytometry. Results: The injury-mediated ROS increases are comparable with other in vivo studies and consistent with our previous observation using a similar injury model and measured with electrophysiological and anatomical technique. Further, ascorbic acid, hypothermia, or the combination of both signi®cantly suppressed superoxide and lipid peroxidation. The combination treatment was the most e ective when compared with ascorbic acid or hypothermia alone. Conclusion: This in vitro model has the advantage of replicating some of the in vivo conditions while gaining the ability to control the experimental conditions. This in vitro model is suitable to study the mechanisms of ROS generation and degradation and can also be used to critically evaluate the e ective suppressor of ROS in the contents of spinal cord traumatic injury.

Effect of postinjury intravenous or intrathecal methylprednisolone on spinal cord excitatory amino-acid release, nitric oxide generation, PGE2 synthesis, and myeloperoxidase content in a pig model of acute spinal cord injury

“…Peroxynitrite is formed by reaction of NO with superoxide anion (O 2 À ), which is elevated in spinal cord injury. [27][28][29] Thus, the persistently elevated concentrations of the highly reactive ONOO À anion observed by Liu et al is best explained by ongoing production of NO in the presence of O 2 À . And, the failure of Liu et al to measure the persistently elevated concentrations of free NO by ion-selective electrode would be explained by the rapid conversion of NO to peroxynitrite.…”

Microglia inhibition is a target of mild hypothermic treatment after the spinal cord injury

“…Hypothermia has been shown to inhibit the elevation of excitatory amino acid concentration in the brain after ischemia, 11 neuronal apoptosis after spinal cord injuries in rabbits 12 and post-traumatic inflammatory cascades such as IL-1b, iNOS and superoxide in the brain. 13,14 Moreover, hypothermia decreases intracranial pressure, increases microcirculation 15 and preserves the blood-brain barrier against ischemic brain damage. 16 These reports suggest that hypothermic treatment may act on delayed mechanisms of CNS damage, and encourage the possibility of clinical use of hypothermic treatment after traumatic or ischemic CNS injury.…”

Increased production of reactive oxygen species contributes to motor neuron death in a compression mouse model of spinal cord injury

“…8,4,21 Hall et al 8,11 have demonstrated that neuronal oxygen radical-induced lipid peroxidation was associated with neuronal cell vulnerability. Luo et al 20,21 have shown that there was an extensive increase of ROS production analyzed by flow cytometry assay after SCI. More recently, studies by Sugawara et al 10 have demonstrated that enhanced ROS, particularly superoxide production, contributed to motor neuron death in the normal, but not transgenic rats overexpressing SOD1 gene.…”

“…20,21 Similarly, oxidation of DCF reflects the general ROS production, particularly the peroxide production. 22,23 After a series of preliminary tests using different doses and different lengths of time of fluorescent dye exposure, we selected DCF dose at 25 mg/kg body weight, HEt dose at 15 mg/kg body weight and 6 h after SCI to analyze the relative levels of ROS production.…”