Effects of clotrimazole on experimental spinal cord ischemia/reperfusion injury in rats.
ABSTRACT The effect of clotrimazole was examined using a spinal cord ischemia/reperfusion model.
Twenty albino Wistar rats weighing 234 +/- 12.3 g were used in this study. Rats were anesthetized intraperitoneally with 50 mg/kg ketamine HCl. All animals underwent laparotomy under aseptic conditions. Abdominal aortas of the animals in all but the sham group were exposed. After opening the retroperitoneum, the infrarenal abdominal aorta was clipped for 45 minutes to produce ischemia/reperfusion injury. Polyethylene glycol (PEG, 1 mL) was administrated to the vehicle group. PEG (1 mL) and clotrimazole (30 mg/kg) were administered intraperitoneally in the clotrimazole group. Total laminectomy of T8-T12 was performed on all rats under a microscope. Spinal cords were excised for a length of 2-cm rostrally and 1-cm caudally to the injury site and deep frozen at -76 degrees C for biochemical studies. The levels of malondialdehyde, glutathione-peroxidase, superoxide dismutase, and catalase were measured as an indicator of ischemia level. The most cranial part of the specimens was evaluated morphologically.
Treatment with clotrimazole significantly decreased malondialdehyde, glutathione-peroxidase, superoxide dismutase, and catalase levels in comparison with other groups (P = 0.008). Morphologic evaluation revealed that clotrimazole protected the axons and their myelin sheaths from ischemic damage.
This study showed the neuroprotective effects of clotrimazole on spinal cord ischemia/reperfusion injury.
- [show abstract] [hide abstract]
ABSTRACT: This study examined the effect of lumbar nerve root compression on nociceptive neuropeptides in the axonal flow using an in vivo model. The aim was to investigate changes in axonal flow after nerve root compression by using immunohistochemical techniques to detect substance P (SP) and somatostatin (SOM), which is thought to be involved in temperature and pain sensation. Disturbance of intraradicular blood flow and nerve fiber deformation caused by mechanical compression are thought to be involved in the pathophysiology of diseases characterized by radicular symptoms, such as lumbar disc herniation and lumbar canal stenosis. However, little research has been conducted into the changes of axonal flow associated with nerve root compression. In dogs, the lumbar nerve roots were compressed using four types of clips with different pressures. Changes of SP and SOM levels in the spinal dorsal horn, dorsal root, and dorsal root ganglions were examined immunohistochemically after compression for 24 hours or 1 week. After compression for 24 hours, axonal flow in the dorsal root was impaired, accumulation of SP and SOM was observed distal to the site of compression, and there was a decrease in the number of dorsal root ganglion cells showing positively for these neurotransmitters. Compression for 1 week resulted in a decrease in the number of SP- and SOM-positive fibers in the spinal dorsal horn. Change of axonal flow resulting from direct nerve compression could affect the metabolism of neurotransmitters that flow inside the axons and may be a primary cause of the decline in nerve function.Spine 03/2005; 30(3):276-82. · 2.16 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Since 1922 when Wu proposed the use of the Folin phenol reagent for the measurement of proteins (l), a number of modified analytical pro- cedures ut.ilizing this reagent have been reported for the determination of proteins in serum (2-G), in antigen-antibody precipitates (7-9), and in insulin (10). Although the reagent would seem to be recommended by its great sen- sitivity and the simplicity of procedure possible with its use, it has not found great favor for general biochemical purposes. In the belief that this reagent, nevertheless, has considerable merit for certain application, but that its peculiarities and limitations need to be understood for its fullest exploitation, it has been studied with regard t.o effects of variations in pH, time of reaction, and concentration of react- ants, permissible levels of reagents commonly used in handling proteins, and interfering subst.ances. Procedures are described for measuring pro- tein in solution or after precipitation wit,h acids or other agents, and for the determination of as little as 0.2 y of protein.Journal of Biological Chemistry 12/1951; 193(1):265-75. · 4.65 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Blood flow in the dorsolateral funiculus of the cat thoracic spinal cord was studied after severe experimental cord injury, using a modification of the hydrogen clearance technique. Autoregulation was intact during the initial 60 to 90 minutes after cord injury, but was then lost coincident with the onset of ischemia. The data suggest that the ischemic response to spinal cord injury is mediated both by the loss of autoregulation and by relative vasoconstriction of the resistance vessels. Therapeutic intervention aimed at maintaining perfusion during the early posttraumatic period may prove of value in reversing or limiting some elements of dysfunction due to the secondary injury of ischemia.Journal of Neurosurgery 03/1979; 50(2):198-206. · 3.15 Impact Factor
SPINE Volume 33, Number 26, pp 2863–2867
©2008, Lippincott Williams & Wilkins
Effects of Clotrimazole on Experimental Spinal Cord
Ischemia/Reperfusion Injury in Rats
Haydar Usul, MD,* Erhan Arslan, MD,* Tufan Cansever, MD,† Umit Cobanoglu, MD,‡
and Su ¨leyman Baykal, MD*
Objective. The effect of clotrimazole was examined
using a spinal cord ischemia/reperfusion model.
Methods. Twenty albino Wistar rats weighing 234 ?
12.3 g were used in this study. Rats were anesthetized
intraperitoneally with 50 mg/kg ketamine HCl. All animals
underwent laparotomy under aseptic conditions. Abdom-
inal aortas of the animals in all but the sham group were
exposed. After opening the retroperitoneum, the infrare-
nal abdominal aorta was clipped for 45 minutes to pro-
duce ischemia/reperfusion injury. Polyethylene glycol
(PEG, 1 mL) was administrated to the vehicle group. PEG
(1 mL) and clotrimazole (30 mg/kg) were administered
intraperitoneally in the clotrimazole group. Total laminec-
tomy of T8–T12 was performed on all rats under a micro-
scope. Spinal cords were excised for a length of 2-cm
rostrally and 1-cm caudally to the injury site and deep
frozen at ?76°C for biochemical studies. The levels of
dismutase, and catalase were measured as an indicator of
ischemia level. The most cranial part of the specimens
was evaluated morphologically.
Results. Treatment with clotrimazole significantly de-
creased malondialdehyde, glutathione-peroxidase, su-
peroxide dismutase, and catalase levels in comparison
with other groups (P ? 0.008). Morphologic evaluation
revealed that clotrimazole protected the axons and their
myelin sheaths from ischemic damage.
Conclusion. This study showed the neuroprotective
effects of clotrimazole on spinal cord ischemia/reperfu-
Key words: clotrimazole, ischemia/reperfusion, cata-
lase, glutathione peroxidase, malondialdehyde, superox-
ide dismutase.Spine 2008;33:2863–2867
Paraplegia is the most challenging complication in oper-
ations involving the descending thoracic and thoracoab-
dominal aorta. This challenge is encountered, despite re-
cent improvements in operation techniques, with an
incidence of 4% to 33% in all operations.1The etiology
of paraplegia is thought to involve anoxia during the
period that the aorta is cross-clamped along with dam-
age to ascending and descending axons. Due to its high
sensitivity to anoxia, the gray matter plays the most im-
portant role in the pathophysiology of spinal cord isch-
Several methods, including hypothermia, cerebrospi-
nal fluid drainage, and calcium channel blockers, have
been tested to protect the spinal cord against ischemia.2,3
Most studies have attempted to prevent excessive cal-
cium (Ca??) influx into the cells during hypoxia/
ischemia. Ca??overload can result in the activation of
dria, the activation of nitric oxide synthase, and the gen-
eration of free oxygen species.4One of the most impor-
tant free radical scavengers is clotrimazole, which is also
known as a potent antimycotic drug. Numerous studies
have shown the radical scavenger effects of clotrimazole
in various human cell types.5The neuroprotective effect
of clotrimazole, through its modulation of Ca??trans-
port and Ca??-dependent intracellular processes, was
shown in primary cerebellar cultures and a spinal cord
injury model.5–7In this study, we aimed to examine the
effect of clotrimazole on a spinal cord ischemia/
reperfusion (I/R) model.
Materials and Methods
Twenty Wistar albino rats weighing 234 ? 12.3 g were used in
this study. The animals were kept under constant laboratory
continuous access to food and tap water. All experiments were
approved by the Institutional Review Board of Karadeniz
Technical University, Faculty of Medicine, and were treated
according to the research guidelines.
Anesthesia and Surgical Procedure
The rats were fasted for 24 hours with free access to water
before the surgical procedure. Anesthesia was induced by in-
tramuscular administration of 50 mg/kg ketamine hydrochlo-
ride (Ketalar, Pfizer, Istanbul). The rats were numbered with
ear tags. Their abdomens were shaved and cleaned with 10%
All animals underwent laparotomy under aseptic condi-
tions. No further intervention was applied to the rats in the
sham group. The surgical incisions of the rats were closed in
layers. The abdominal aortas of the animals in the treatment
groups were exposed after opening the retroperitoneum. An
aneurysm clip with 50-g closing force (Yasargil FE 693, Aeus-
culab, Germany) was applied to the abdominal aorta below the
renal artery orifices for a period of 45 minutes. Rats were ran-
domly allocated into 4 groups: a sham group of 5 rats in which
From the *Department of Neurosurgery, Karadeniz Technical Univer-
sity School of Medicine, Trabzon; †Department of Neurosurgery, Gul-
hane Military Medical School, Ankara; and ‡Department of Pathol-
ogy, Karadeniz Technical University School of Medicine, Trabzon,
Acknowledgment date: February 11, 2008. Revision date: June 16,
2008. Acceptance date: July 20, 2008.
The manuscript submitted does not contain information about medical
No funds were received in support of this work. No benefits in any
form have been or will be received from a commercial party related
directly or indirectly to the subject of this manuscript.
All experiments were approved by the Institutional Review Board of
Karadeniz Technical University, Faculty of Medicine, and were treated
according to the research guidelines.
Address correspondence and reprint requests to Erhan Arslan, MD,
Department of Neurosurgery, KTU Tip Fakultesi, Norosirurji AD,
61080 Trabzon, Turkey; E-mail: firstname.lastname@example.org
only surgical laparotomy was performed; a trauma group of 5
rats in which aneurysmal clip application to the abdominal
aorta was performed but no treatment was given; a vehicle
group of 5 rats in which 1 mL polyethylene glycol (PEG) was
administered intraperitoneally following application of the an-
eurysmal clip; and a clotrimazole group of 5 rats in which
aneurysmal clip application was performed and clotrimazole
(30 mg/kg) was administered intraperitoneally 5 minutes after
the removal of the aneurysm clip.
Clotrimazole was dissolved in water containing acidified 3%
Sacrificing of Animals and Sample Preparation
The rats were killed 24 hours postischemia, using an overdose
of pentobarbital. Spinal cord segments were excised between
T8 and T12 levels, divided into 4 equal parts and 3 caudal
parts, and stored immediately in a ?76°C freezer for homoge-
Kunkel, Germany) was used at 9500 rpm (4 ? 10 sec at 4°C).
The most cranial parts of the specimens obtained at surgical
resection were processed using glutaraldehyde fixation and
resin embedding. Ultra-thin sections were stained with uranyl
acetate and lead citrate and numbered by the laboratory tech-
nician in order to blind the investigator to the groups. Results
were analyzed according to the codes given at the pathology
laboratory. Morphologic evaluation of the sections was con-
ducted under an electron microscope by a blinded pathologist.
Measurement of Malondialdehyde Levels and
Antioxidant Enzyme Activities
Lipid peroxidation in spinal cord samples was determined as
malondialdehyde (MDA) concentration, by the method of Mi-
with 3 mL of 1% H3PO4. After adding 1 mL of 0.67% thio-
barbituric acid, the mixture was heated in boiling water for 45
minutes. The formed color was extracted into n-butanol. The
mixture was centrifuged at 4000 rpm for 10 minutes at room
temperature. Absorbance of the organic layer was read at 532
nm. Tetramethoxypropane was used as a standard, and MDA
levels were calculated as nanomoles per gram wet tissue.
Superoxide Dismutase. Superoxide dismutase (SOD) activi-
ties were measured by the inhibition of nitroblue tetrazolium
reduction in the xanthine–xanthine oxidase system.9Enzyme
activity leading to 50% inhibition was accepted as 1 unit, and
results were expressed as U/mg protein. Protein concentrations
were determined according to Lowry’s method.10
Glutathione Peroxidase. Glutathione peroxidase (GSH-PX)
activities were measured by the method of Paglia and Valen-
tine, using a RANSEL (Randox, Antrim, UK) kit.11In this kit,
GSH-PX activity is coupled with the oxidation of NADPH by
glutathione reductase. Oxidation of NADPH was followed
spectrophotometrically (340 nm) at 37°C. Results were ex-
pressed as U/mg protein.
Catalase. Catalase (CAT) activity was determined by the
method of Aebi (1974).12The principle of CAT activity was
based on the determination of the rate constant (k, sec?1) or of
the hydrogen peroxide decomposition rate at 240 nm. Results
were expressed as k/g of protein.
Comparison among the groups was made using the Kruskal–
Wallis analysis of variance and the Mann-Whitney U test. Re-
sults were expressed as mean, standard deviation, median, and
range. Results were considered as significant with P ? 0.05.
The sham group had the lowest MDA levels (30.2 ? 4.5
nm/g), whereas the trauma group had the highest MDA
levels (71.4 ? 17.7 nm/g) (Table 1). When the MDA
levels of the groups were compared with Kruskal–Wallis
variance analysis, all of the results were statistically sig-
nificant (P ? 0.001). When the groups’ MDA levels were
compared using the post hoc Mann-Whitney U test, the
trauma group had significantly higher levels than those
in the clotrimazole (P ? 0.008), sham (P ? 0.008), and
PEG group (P ? 0.008).
GSH-PX levels were lowest in the sham (115 ? 14.3
U/mg) and highest in the trauma group (168 ? 24.1
U/mg). When the GSH-PX levels were compared using
Kruskal-Wallis variance analysis, the results were statis-
tically significant (P ? 0.001). The differences between
the trauma group and the other groups were statistically
significant (P ? 0.001) when the groups were compared
using the post hoc Mann-Whitney U test (Table 2), but
there was no significant difference between the sham and
Table 1. MDA Levels of the Groups
GroupMean Standard DeviationMin-Max
Table 3. SOD Levels of the Groups
Group Mean Standard DeviationMin-Max
Table 2. GSH-PX Levels of the Groups
GroupMean Standard DeviationMin-Max
2864Spine•Volume 33•Number 26•2008
The SOD levels were lowest in the clotrimazole group
(2.88 ? 0.19 U/mg) and highest in the trauma group
(3.72 ? 0.48 U/mg) (Table 4). When the SOD levels of
the groups were compared using Kruskal–Wallis vari-
ance analysis, the results were not statistically significant
(P ? 0.091). The post hoc Mann-Whitney U test also
demonstrated that the results were not statistically sig-
nificant (P ? 0.091) (Table 3).
The clotrimazole treatment group had the lowest
CAT Levels (5.90 ? 1.31 k/g), whereas the highest levels
were observed in the trauma group (10.46 ? 2.91 k/g).
The differences between the trauma and all other groups
were statistically significant when the groups were com-
pared using the post hoc Mann-Whitney U test (P ?
0.025) (Table 4). There was no significant difference be-
tween the sham and treatment groups.
Ultrastructural examination revealed normal appear-
ance of axon and myelin sheath structures, with intact
nerve cells in the sham group (Figure 1), severe degener-
ation of the myelin sheath, and edema in the trauma
group (Figure 2); almost normal architecture of white
matter, with mild dispersion of the myelin sheath of
some nerve fibers in the clotrimazole group (Figure 3);
and marked dispersion of myelin sheaths, with edema-
tous spaces between axons in the PEG group (Figure 4)
similar to those in the trauma group.
icals produced during and after ischemia. The ischemic
days, even after normal blood flow is regained. This cas-
in a linear fashion. However, “ischemic cascade” is ac-
tually a misnomer since its events are not always linear
and, in some cases, can be circular. In some cases, one
event can cause, or be caused, by multiple other events.13
In addition, cells receiving varying degrees of perfusion
may initiate different chemical processes. Despite these
as shown in Figure 5.
Experimental lumbar nerve root compression using in
vivo models has also been studied by Kobayashi et al.
Kobayashi et al measured the changes in the nociceptive
neuropeptide substance P and somatostatin by using im-
munohistochemical techniques, which are thought to be
involved in temperature and pain sensation.14They sug-
gested that the probable cause of the decline in nerve
function after nerve compression was the change in ax-
onal flow, which could affect the metabolism of neuro-
Kobayashi et al also showed that nerve root compression
causes Wallerian degeneration not only at the site of
Table 4. CAT Levels of the Groups
GroupMean Standard DeviationMin-Max
Figure 1. Ultrastructural examination revealed normal-appearing
axons and myelin sheaths with intact nerve cells in the sham
Figure 2. Tissue sample from the trauma group exhibited edema
between axons. The axons showed severe degeneration of myelin
Figure 3. Ultrastructural findings demonstrating almost normal ar-
chitecture of the white matter, with mild dispersion of the myelin
sheaths of some nerve fibers in the clotrimazole group.
2865 Clotrimazole Effect on Spinal Cord Ischemic Injury•Usul et al
the dorsal horns of the spinal cord.15
When a neuron is reperfused, a number of factors lead
to reperfusion injury, including the mounted inflamma-
tory response in which phagocytic cells engulf damaged
but still viable tissue.
ROS induce cell damage. ROS are either free radicals,
reactive anions containing oxygen atoms, or molecules
containing oxygen atoms that can either produce free
radicals or be chemically activated by them. Examples of
ROS include hydroxyl radical, superoxide, hydrogen
peroxide, and peroxynitrite. The main source of ROS in
vivo is aerobic respiration, although these are also pro-
duced by peroxisomal ?-oxidation of fatty acids, micro-
somal cytochrome P450 metabolism of xenobiotic com-
pounds, stimulation of phagocytosis by pathogens or
lipopolysaccharides, arginine metabolism, and tissue-
specific enzymes.16One of the most frequently used bi-
oxidation level is the plasma concentration of MDA, one
of several byproducts of lipid peroxidation processes.17
In our study, high MDA levels in the I/R group in com-
parison with the sham group showed that ischemia
causes the lipid peroxidation (P ? 0.001).
Metabolic bursts, in which oxygen is reduced to
droxyl radical (OH?), can be elicited by various stim-
uli.17,18Defense against such toxicity is provided by
scavengers and detoxifying reactions, catalyzed
mainly by antioxidant enzymes such as SOD, CAT,
and the glutathione cycle, including reduced glutathi-
one, oxidized glutathione, glutathione reductase, and
GSH-PX (Table 5).19
SOD, CAT, and GSH-PX are the most important intra-
?), hydrogen peroxide (H2O2), and hy-
Figure 4. Ultrastructural findings from the PEG group suggest
similarities to the trauma group. The axons displayed marked
dispersion of myelin sheaths with edematous spaces between
Figure 5. Hypoxia causes a fail-
ure in the neurons’ normal path-
ways for adenosine triphosphate
production. This results in depo-
larization of the cell, uncon-
trolled influx of Ca??, and an
inability of the Ca??pumps to
transport Ca??out of the cell.
Presynaptically, the presence of
Ca??triggers the release of the
excitatory amino acid neuro-
transmitter glutamate. Glutamate
stimulates the postsynaptic
(AMPA) receptors and Ca??-
receptors, which open to allow
more Ca??into cells. Excess
Ca??entry overexcites the cells
and causes the generation of
harmful chemicals, including
free radicals, reactive oxygen
species, and Ca??-dependent
enzymes such as calpain, endo-
nucleases, ATPases, and phos-
pholipases in a process called
excitotoxicity. Likewise, protein
kinase C activation promotes
which contributes to lipid peroxidation that can be assessed by MDA levels. As the cell’s membrane is damaged by phospholipases, it
becomes more permeable, and more ions and harmful chemicals flow into the cell. Mitochondria break down, releasing toxins and
apoptotic factors into the cell. The caspase-dependent apoptosis cascade is initiated, causing the cell to “commit suicide.” If the cell dies
through necrosis, it releases glutamate and toxic chemicals into the surrounding environment, which may poison nearby neurons or
overexcite them via released glutamate.
2866 Spine•Volume 33•Number 26•2008
cellular antioxidants in humans, and many studies relat-
ing to their activity levels have been conducted to moni-
tor their roles in protection from peroxidation and tissue
injury.20Increased levels of SOD, GSH-PX, and CAT
activity in the trauma group in comparison with the
sham group showed significant production of ROS in the
I/R model. Increased MDA levels are consistent with
these results (P ? 0.001). Clotrimazole inhibits cyto-
lular metabolism and signaling, especially in Ca??-
dependent processes.21,22Clotrimazole inhibits the
ischemic cascade through the modulation of Ca??trans-
port and Ca??-dependent processes, while also partially
blocking N-methyl-D-aspartate (NMDA) receptors, thus
causing both reduced Ca??overload and a reduced
probability of mitochondrial potential collapse.5After
PEG and clotrimazole application, MDA, GSH-PX, and
CAT activities were decreased significantly in compari-
son with those in the trauma group (P ? 0.001, P ?
0.001, P ? 0.025). Both substances decreased the I/R-
related injury significantly and caused low ROS produc-
tion and MDA levels. Enzyme activities were decreased
significantly probably due to the low ROS levels. Oxida-
tive stress was decreased significantly by PEG and clo-
trimazole. Despite significant antioxidant effects of PEG
(P ? 0.002), the effect of clotrimazole demonstrated
greater significance (P ? 0.001). After clotrimazole ap-
plication, the enzyme and MDA levels were very similar
to those in the sham group, which demonstrates the po-
tent antioxidant effect of clotrimazole. The same effect
was found on morphologic evaluation of the sections,
as very mild morphologic changes were found in the
clotrimazole group in comparison with those in the
sham group (Figure 3). The morphologic changes ap-
peared to be more significant in the PEG group, which,
similar to the trauma group, showed marked disper-
sion of myelin sheaths with edematous spaces between
axons (Figure 4).
This antioxidant effect was assessed in a rat spinal I/R
model. The levels of catalase SOD, GSH-PX, CAT, and
MDA were measured as indicators of ischemia severity.
The neuroprotective effect of clotrimazole was shown.
Further studies need to be conducted, using larger ani-
mals and other spinal cord injury models.
● Clotrimazole is an oxygen free radical scavenger.
● Clotrimazole showed a neuroprotective effect in
the ischemia/reperfusion model.
● Antioxidant enzymes were used to show the ef-
fect of clotrimazole.
● Morphologic evaluation showed the neuropro-
tective effect of clotrimazole too.
1. Sun Y, Oberley LW, Li Y. A simple method for clinical assay of superoxide
dismutase. Clin Chem 1988;34:497–500.
2. Lipton SA. Neuronal protection and destruction by NO. Cell Death Differ
3. Usul H, Cakir E, Arslan E, et al. Effects of clotrimazole on experimental
spinal cord injury. Arch Med Res 2006;37:571–75.
4. Isaev NK, Stelmashook EV, Dirnagl U, et al. Neuroprotective effects of the
antifungal drug clotrimazole. Neuroscience 2002;113:47–53.
5. Hinkle J, Bowman L. Neuroprotection for ischemic stroke. J Neurosci Nurs
6. Svensson LG. Paralysis after aortic surgery: in search of lost cord function.
7. Wan IY, Angelini GD, Bryan AJ, et al. Prevention of spinal cord ischaemia
during descending thoracic and thoracoabdominal aortic surgery. Eur J Car-
diothorac Surg 2001;19:203–13.
8. Mihara M, Uchiyama M. Determination of malonaldehyde precursor in
tissues by thiobarbituric acid test. Anal Biochem 1978;86:271–78.
9. Senter HJ, Venes JL. Loss of autoregulation and posttraumatic ischemia
following experimental spinal cord trauma. J Neurosurg 1979;50:198–206.
10. Lowry OH, Rosebrough NJ, Farr AL, et al. Protein measurement with the
Folin phenol reagent. J Biol Chem 1951;193:265–75.
11. Nicholls DG, Budd SL. Mitochondria and neuronal survival. Physiol Rev
12. Aebi U, Bijlenga R, v d Broek H, et al. The transformation of tau particles
into T4 heads. II. Transformations of the surface lattice and related obser-
vations on form determination. J Supramol Struct 1974;2:253–75.
13. Hassan HM, Schrum LV. Roles of manganese and iron in the regulation of
the biosynthesis of manganese superoxide dismutase in E. coli. FEMS Mi-
crobiol Rev 1994;14:315–24.
14. Kobayashi S, Kokubo Y, Uchida K, et al. Effects of lumbar nerve root com-
pression on primary sensory neurons and their central branches: changes in
the nociceptive neuropeptides substance P and somatostatin. Spine 2005;30:
15. Kobayashi S, Uchida K, Kokubo Y, et al. Synapse involvement of the dorsal
horn in experimental lumbar nerve root compression: a light and electron
microscopic study. Spine 2008;33:716–23.
16. Fridovich I. Superoxide dismutases. Adv Enzymol Relat Areas Mol Biol
17. Church DF, Pryor WA. Free radical chemistry of cigarette smoke and its
toxicological implications. Environ Health Perspect 1985;64:111–26.
18. Dickens BF, Mak IT, Weglicki WB. Lysosomal lipolytic enzymes, lipid per-
oxidation, and injury. Mol Cell Biochem 1988;82:119–23.
19. Fiers W, Beyaert R, Declercq W, et al. More than one way to die: apoptosis,
necrosis and reactive oxygen damage. Oncogene 1999;18:7719–30.
20. Badwey JA, Karnovsky ML. Active oxygen species and the functions of
phagocytic leukocytes. Annu Rev Biochem 1980;49:695–726.
21. Burdon RH, Rice –Evans C. Free radicals and the regulation of mammalian
cell proliferation. Free Radic Res Commun 1989;6:345–58.
22. Yoshida Y, Aoyama Y. Interaction of azole antifungal agents with cyto-
chrome P-45014DM purified from Saccharomyces cerevisiae microsomes.
Biochem Pharmacol 1987;36:229–35.
Table 5. Antioxidant Enzymes and Their Activities
Antioxidant Enzymes ROS and Their Reactions
2O2? 2H?3 H2O2? O2
2GSH ? H2O23 SSG ? 2H2O
??3 H2O ? O2
2867Clotrimazole Effect on Spinal Cord Ischemic Injury•Usul et al