ISSN 1806-3713
© 2016 Sociedade Brasileira de Pneumologia e Tisiologia
http://dx.doi.org/10.1590/S1806-37562016000000183
ABSTRACT
Objective:
To investigate the effects of N-acetylcysteine (NAC) and pentoxifylline in
a model of remote organ injury after hind-limb ischemia/reperfusion (I/R) in rats, the
lungs being the remote organ system. Methods: Thirty-ve male Wistar rats were
assigned to one of ve conditions (n = 7/group), as follows: sham operation (control
group); hind-limb ischemia, induced by clamping the left femoral artery, for 2 h, followed
by 24 h of reperfusion (I/R group); and hind-limb ischemia, as above, followed by
intraperitoneal injection (prior to reperfusion) of 150 mg/kg of NAC (I/R+NAC group),
40 mg/kg of pentoxifylline (I/R+PTX group), or both (I/R+NAC+PTX group). At the end
of the trial, lung tissues were removed for histological analysis and assessment of
oxidative stress. Results: In comparison with the rats in the other groups, those in the
I/R group showed lower superoxide dismutase activity and glutathione levels, together
with higher malondialdehyde levels and lung injury scores (p < 0.05 for all). Interstitial
inammatory cell inltration of the lungs was also markedly greater in the I/R group than
in the other groups. In addition, I/R group rats showed various signs of interstitial edema
and hemorrhage. In the I/R+NAC, I/R+PTX, and I/R+NAC+PTX groups, superoxide
dismutase activity, glutathione levels, malondialdehyde levels, and lung injury scores
were preserved (p < 0.05 for all). The differences between the administration of NAC
or pentoxifylline alone and the administration of the two together were not signicant
for any of those parameters (p > 0.05 for all). Conclusions: Our results suggest that
NAC and pentoxifylline both protect lung tissue from the effects of skeletal muscle I/R.
However, their combined use does not appear to increase the level of that protection.
Keywords: Skeletal muscle; Ischemia; Reperfusion injury; Lung injury; Acetylcysteine;
Pentoxifylline.
Effects of N-acetylcysteine and pentoxifylline
on remote lung injury in a rat model of hind-
limb ischemia/reperfusion injury
Hamed Ashrafzadeh Takhtfooladi
1
, Saeed Hesaraki
1
, Foad Razmara
2
,
Mohammad Ashrafzadeh Takhtfooladi
3
, Hadi Hajizadeh
4
Correspondence to:
Mohammad Ashrafzadeh Takhtfooladi. Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Tel.: 00989132004875. Fax: 00983117860211. Email: dr_ashrafzadeh@yahoo.com
Financial support: None.
INTRODUCTION
Re-establishing perfusion in a tissue after a period of
ischemia worsens the initial ischemic injury. This process is
known as ischemia/reperfusion (I/R) injury.
(1)
Such injury
constitutes an important clinical event and is common
in the lower extremities. Although restoration of blood
ow can save the extremity, it can also result in multiple
organ dysfunction syndrome.
(2)
For example, I/R of a
lower limb leads to noncardiogenic pulmonary edema
by means of pulmonary vasoconstriction, pulmonary
hypertension, and increased alveolar membrane permea-
bility.
(3)
Pulmonary dysfunction after I/R injury of a lower
extremity continues to be a major cause of morbidity and
mortality.
(4)
Previous studies have suggested that oxygen
free radicals, inammatory mediators, and, especially,
neutrophils play an important role in the development
of lung injury related to I/R in a lower limb.
(5,6)
Various agents have been reported to reduce remote
lung injury after hind-limb I/R in rats.
(7-9)
N-acetylcysteine
(NAC) is an antioxidant that acts by increasing intracellular
levels of glutathione, as well as by direct scavenging of
reactive oxygen species (ROS) such as hypochlorous acid,
hydrogen peroxide, superoxide, and hydroxyl radical.
(10)
Pentoxifylline, a nonspecic phosphodiesterase inhibitor,
has been shown to improve tissue oxygenation and
endothelial function as well as inhibiting pro-inammatory
cytokine production.
(11)
Pentoxifylline also inhibits cell
proliferation and extracellular matrix accumulation.
(12)
Therefore, in the present study, we evaluated the pos-
sible involvement of oxidative stress in skeletal muscle
I/R-induced lung injury in rats by examining the effects
of pentoxifylline, NAC, and the combination of the two.
METHODS
All experimental procedures were performed in accord-
ance with established guidelines for the ethical treatment
of experimental animals, and the study was approved by
the Institutional Animal Care and Use Committee of the
Islamic Azad University School of Veterinary Medicine,
in the city of Tehran, Iran.
Thirty-ve healthy adult male Wistar rats, 90-120 days
of age and weighing 250-350 g, were purchased from
the Pasteur Institute of Iran. The animals were housed
in a temperature- and humidity-controlled environment
1. Department of Pathobiology, Science
and Research Branch, Islamic Azad
University, Tehran, Iran.
2. Doctor of Veterinary Medicine, Novin
Pet Clinic, Isfahan, Iran.
3. Young Researchers and Elites Club,
Science and Research Branch, Islamic
Azad University, Tehran, Iran.
4. Department of Clinical Science, Science
and Research Branch, Islamic Azad
University, Tehran, Iran.
Submitted: 29 July 2015.
Accepted: 4 November 2015.
Study carried out at the Young
Researchers and Elites Club, Science and
Research Branch, Islamic Azad University,
Tehran, Iran.
J Bras Pneumol. 2016;42(1):9-14
9
ORIGINAL ARTICLE
Effects of N-acetylcysteine and pentoxifylline on remote lung injury in a rat model of hind-limb ischemia/reperfusion injury
(22 ± 1°C; relative humidity, 50 ± 5%), on a 12/12-h
light/dark cycle, with ad libitum access to a commercial
pellet diet and ltered tap water. The animals were
randomly divided into ve experimental groups of
seven rats each: an I/R group, in which the animals
were subjected to 2 h of hind-limb ischemia, induced
by clamping the left femoral artery, followed by
intraperitoneal administration of 2 mL of 0.9% saline
solution and 24 h of reperfusion; a sham-operated
(control) group, in which the animals were subjected
to all surgical procedures except arterial occlusion and
also received 0.9% saline (2 mL, i.p.); an I/R+NAC
group, in which the animals were subjected to I/R,
as described above, and received 150 mg/kg of NAC
in 0.9% saline solution (i.p., in a total volume of 2
mL); an I/R+PTX group, in which the animals were
subjected to I/R, as described above, and received 40
mg/kg of pentoxifylline in 0.9% saline solution (i.p.,
in a total volume of 2 mL); and an I/R+NAC+PTX
group, in which the animals were subjected to I/R,
as described above, and received a combination of
NAC and pentoxifylline (at the doses listed above) in
0.9% saline solution (i.p., in a total volume of 2 mL).
The rats were weighed, after which they were anes-
thetized with a combination of ketamine hydrochloride
10% and xylazine hydrochloride 2% (i.m., 50 mg/kg
and 10 mg/kg, respectively). The animals were placed
on a warming pad, in dorsal recumbency, their thoraces
and hind limbs immobilized with adhesive tape. After
aseptic surgical preparation, 250 IU of heparin were
administered via the jugular vein (in order to prevent
clotting) and a skin incision was made on the medial
surface of the left hind limb. After isolating the left
femoral artery from the surrounding tissues, we induced
ischemia by using a microvascular clamp to occlude
the artery for 2 h. Throughout the period of ischemia,
the animals were maintained in dorsal recumbency
and remained anesthetized (additional doses given
as necessary). Body temperature was monitored
with a rectal thermometer. At the end of the period of
ischemia, the clamp was removed and the surgical site
was routinely closed with 4/0 polypropylene sutures.
Animals in the control group underwent a similar
surgical procedure, although without arterial occlusion.
The rats subjected to ischemia then underwent 24 h
of reperfusion. Throughout the periods of ischemia
and reperfusion, the animals received noninvasive
ventilatory support.
At the end of the experimental period, all of the rats
were euthanized with an overdose of pentobarbital
(300 mg/kg, i.p.) and the lungs were removed en
bloc. The left lungs were immersed in 10% formalin
solution, and the right lungs were stored at −20°C
for subsequent biochemical analysis. The lung tissue
homogenate and supernatant samples were prepared
as described by Yildirim et al.
(13)
Malondialdehyde
levels, superoxide dismutase (SOD) activity, and
glutathione levels were measured in the right lungs,
whereas samples of the left lungs were submitted to
histopathological evaluation under light microscopy.
Malondialdehyde levels were determined by thio-
barbituric acid reaction, as described by Yagi.
(14)
In
the thiobarbituric acid reaction test, malondialdehyde
(or malondialdehyde-like substances) react with
thiobarbituric acid to produce a pink chromogen with
peak absorbance at 532 nm on a spectrophotometer.
The tissue levels of malondialdehyde are expressed
as nmol/g of tissue.
The SOD activity was determined according to the
method devised by Winterbourn et al.,
(15)
assayed as
inhibition of the photochemical reduction of nitroblue
tetrazolium at 560 nm. The SOD activity is expressed
as U/g of tissue.
Glutathione levels were determined by the
method described by Ellman,
(16)
in which the level
of glutathione is considered directly proportional to
the rate of formation of the reduced chromogen,
5,5′-dithiobis(2-nitrobenzoic acid), as determined by
measuring its absorbance at 412 nm. The results are
expressed as nmol/g of tissue.
The left lung specimens were xed in 10% buffered
formalin, processed by standard techniques, and
embedded in parafn. Cross-sectional slices (5-µm
thick) were taken from the middle zones of the lungs
and mounted on slides. The slides were stained
with hematoxylin and eosin, after which they were
examined under light microscopy by a pathologist
who was blinded to the groups. Lung injury was
evaluated semiquantitatively with the classication
system established by Koksel et al.
(17)
: grade 0,
normal appearance; grade 1, mild-to-moderate
interstitial congestion and neutrophil inltration; grade
2, perivascular edema, partial destruction of the lung
architecture, and moderate neutrophil inltration; and
grade 3, complete destruction of the lung architecture
and dense neutrophil inltration. A total of ve slides
from each lung sample were randomly screened, and
the mean was accepted as the representative value
of the sample.
All results are shown as mean ± standard deviation.
The analytical results were evaluated using the Statistical
Package for the Social Sciences, version 16.0 (SPSS
Inc., Chicago, IL, USA). Statistical analysis was done
by analysis of variance. Values of p < 0.05 were
considered statistically signicant.
RESULTS
As can be seen in Figure 1, the malondialdehyde
levels were signicantly higher in the I/R group than
in any of the other groups (p < 0.05). In addition, the
malondialdehyde levels were lower in the I/R+NAC+PTX
group than in the I/R+NAC and I/R+PTX groups, although
the differences were not statistically signicant. The
SOD activity was signicantly lower in the I/R group
than in the control group (Figure 2), whereas it was
signicantly higher in the I/R+NAC, I/R+PTX, and I/
R+NAC+PTX groups than in the I/R group (p < 0.05).
Although SOD activity was highest in the I/R+NAC+PTX
group, there were no signicant differences among the
10
J Bras Pneumol. 2016;42(1):9-14
Takhtfooladi HA, Hesaraki S, Razmara F, Takhtfooladi MA, Hajizadeh H
I/R+PTX, I/R+NAC, and I/R+NAC+PTX groups in terms
of SOD activity. Glutathione levels were also signicantly
lower in the I/R group than in the control group (Figure
3), whereas they were signicantly higher in the I/
R+NAC, I/R+PTX, and I/R+NAC+PTX groups than in
the I/R group. Although glutathione levels were higher
in the I/R+NAC+PTX group than in the I/R+NAC and
I/R+PTX groups, the differences among those three
groups were not signicant. The mean histopathological
lung scores are shown, by group, in Figure 4. The mean
I/R group score was signicantly lower than was that
of the I/R+NAC, I/R+PTX, and I/R+NAC+PTX groups,
although lung injury scores did not differ signicantly
among the three treated groups. As shown in Figure 5,
interstitial inammatory cell inltration was markedly
more pronounced in the lung samples from rats in the
I/R group than in those from rats in the other groups.
The lungs of I/R group rats also showed various signs
of interstitial edema and hemorrhage.
DISCUSSION
Peripheral artery clamping is routinely used during
orthopedic surgery or trauma, in elective and emergency
procedures. Lung damage has been shown to occur
following transient arterial occlusion. The ischemic
damage results from a decrease in the blood ow to an
organ. When blood ow is restored, more pronounced
damage, known as reperfusion injury, occurs. It has
been suggested that oxidative stress plays a role in the
development of I/R injury.
(18)
Various tissue markers of
oxidative stress have been measured to evaluate the
effects of I/R injury. It is known that ROS, which are
potent oxidizing and reducing agents that can directly
damage cellular membranes by lipid peroxidation, are
overproduced during oxidative stress.
(19)
Peroxidation
of endogenous lipids leads to the conversion of reduced
glutathione to glutathione-disulde.
(20)
Malondialdehyde
is an end product derived from the peroxidation of
polyunsaturated fatty acids and related esters. Therefore,
tissue levels of malondialdehyde are a valid reection
of lipid peroxidation. Another line of cellular defense
against free radicals is a system of three enzymes, SOD,
catalase, and glutathione peroxidase. SOD catalyzes
the conversion of superoxides to hydrogen peroxide,
which is subsequently converted to water and oxygen
by catalase or glutathione peroxidase. Because it
plays such a key role in cellular defense against free
Control
*
I/R
I/R+NAC I/R+PTX I/R+NAC+
PTX
MDA (nmol/g tissue)
160
140
120
100
80
60
40
20
0
Control
*
I/R
I/R+NAC I/R+PTX I/R+NAC+
PTX
SOD (U/g tissue)
100
80
60
40
20
0
Control
*
I/R
I/R+NAC I/R+PTX I/R+NAC+
PTX
GSH (nmol/g tissue)
80
60
40
20
0
Control
*
I/R
I/R+NAC I/R+PTX I/R+NAC+
PTX
Lung injury scores
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Figure 4. Histological lung injury scores after 2 h of hind-
limb ischemia and 24 h of reperfusion. I/R: ischemia/
reperfusion; NAC: N-acetylcysteine; and PTX: pentoxifylline.
*p < 0.05 vs. all other groups.
Figure 3. Glutathione (GSH) levels in lung tissue after
2 h of hind-limb ischemia and 24 h of reperfusion. I/R:
ischemia/reperfusion; NAC: N-acetylcysteine; and PTX:
pentoxifylline. *p < 0.05 vs. all other groups.
Figure 2. Superoxide dismutase (SOD) activity in lung tissue
after 2 h of hind-limb ischemia and 24 h of reperfusion.
I/R: ischemia/reperfusion; NAC: N-acetylcysteine; and PTX:
pentoxifylline. *p < 0.05 vs. all other groups.
Figure 1. Malondialdehyde (MDA) levels in lung tissue after
2 h of hind-limb ischemia and 24 h of reperfusion. I/R:
ischemia/reperfusion; NAC: N-acetylcysteine; and PTX:
pentoxifylline. *p < 0.05 vs. all other groups.
11
J Bras Pneumol. 2016;42(1):9-14
Effects of N-acetylcysteine and pentoxifylline on remote lung injury in a rat model of hind-limb ischemia/reperfusion injury
radicals, SOD is also an important indicator of the
oxidative state.
(21)
The glutathione precursor NAC is a small molecule
containing a thiol group, which has antioxidant
properties, and is freely lterable with ready access
to intracellular compartments.
(22)
The diversity of
pharmacological applications of NAC is due mainly to
the chemical properties of the cysteinyl thiol group
of its molecule, the ability of reduced thiol groups
to scavenge oxygen free radicals having been well
established.
(23-25)
In addition, NAC has a variety of
anti-inammatory effects.
(26,27)
In previous rat studies,
the administration of NAC at doses of approximately
400 mg/kg has been shown to protect organs against
oxidative damage.
(28,29)
In the present study, we
found that NAC administration after ischemia (prior to
reperfusion) resulted in lower malondialdehyde levels,
greater SOD activity, and higher glutathione levels in
comparison with no treatment. In other words, NAC
effectively attenuated the I/R-induced increase in the
level of malondialdehyde.
Pentoxifylline is a methylxanthine derivative with
multiple hemorheological properties. Pentoxifylline acts
by increasing intracellular cyclic adenosine monophos-
phate on red blood cells, thus improving oxygen
delivery to ischemic tissues, increasing cyclic adenosine
monophosphate on polymorphonuclear leukocytes,
and decreasing oxygen free radical production.
(30-33)
Recent reports suggest that pentoxifylline can enhance
the chemotactic response of neutrophils, as well as
inhibiting phagocytosis and superoxide production
by neutrophils and monocytes.
(34)
Those ndings
have translated into clinical benets, pentoxifylline
having been used in order to attenuate I/R injury in
patients with lung, intestinal, or kidney damage.
(31)
Previous studies have shown that supplementation
with 50 mg/kg of pentoxifylline has the benecial
effect of reducing oxidative stress and inammatory
indices in I/R-induced spinal cord injury and fatty
liver disease.
(35,36)
In the present study, pentoxifylline
administration after ischemia (prior to reperfusion)
resulted in lower malondialdehyde levels, greater SOD
A B
C
E
D
Figure 5. Lung tissue samples stained with hematoxylin and eosin (original magnication, ×100): (A) control group
sample, showing no remarkable pathological changes; (B) ischemia/reperfusion (I/R) group sample, showing widespread
histological changes such as edema, severe alveolar congestion, alveolar collapse, and inammatory cell inltration;
and (C, D, and E, respectively) I/R+N-acetylcysteine, I/R+pentoxifylline, and I/R+N-acetylcysteine+pentoxifylline group
samples, all showing fewer histological alterations (markedly less interstitial edema and inammatory cell inltration)
in comparison with the I/R group sample.
12
J Bras Pneumol. 2016;42(1):9-14
Takhtfooladi HA, Hesaraki S, Razmara F, Takhtfooladi MA, Hajizadeh H
activity, and higher glutathione levels in comparison
with no treatment.
In conclusion, the signicant I/R-induced increase
in malondialdehyde levels, decrease in glutathione
levels, and destructive appearance on histology of
the lung suggest that skeletal muscle I/R-induced
lung injury is mediated by oxidative reactions. The
results of our study conrm that pentoxifylline and
NAC are both protective against I/R injury. These
effects might be, at least in part, due to the inhibition
of ROS production. To our knowledge, this was the rst
study to compare the effects of these two substances
on remote lung injury. We found that the antioxidant
properties of pentoxifylline were comparable to those of
NAC. However, we observed no additional effect when
the two were administered in combination. Further
studies are needed in order to determine the clinical
importance of treatment with pentoxifylline and NAC,
especially regarding the possible mechanisms other
than ROS scavenging. Such treatments might prove
effective for enhancing protection of the lungs after
lower-limb I/R.
REFERENCES
1. Li C, Jackson RM. Reactive species mechanisms of cellular hypoxia-
reoxygenation injury. Am J Physiol Cell Physiol. 2002;282(2):C227-41.
http://dx.doi.org/10.1152/ajpcell.00112.2001
2. Yassin MM, Harkin DW, Barros D’Sa AA, Halliday MI, Rowlands
BJ. Lower limb ischemia-reperfusion injury triggers a systemic
inammatory response and multiple organ dysfunction. World J Surg.
2002;26(1):115-21. http://dx.doi.org/10.1007/s00268-001-0169-2
3. Groeneveld AB, Raijmakers PG, Rauwerda JA, Hack CE. The
inammatory response to vascular surgery-associated ischaemia and
reperfusion in man: effect on postoperative pulmonary function. Eur
J Vasc Endovasc Surg. 1997;14(5):351-9. http://dx.doi.org/10.1016/
S1078-5884(97)80284-5
4. Paterson IS, Klausner JM, Pugatch R, Allen P, Mannick JA, Shepro
D, et al. Noncardiogenic pulmonary edema after abdominal aortic
aneurysm surgery. Ann Surg. 1989;209(2):231-6. http://dx.doi.
org/10.1097/00000658-198902000-00015
5. Welbourn CR, Goldman G, Paterson IS, Valeri CR, Shepro D,
Hechtman HB. Pathophysiology of ischaemia reperfusion injury:
central role of the neutrophil. Br J Surg. 1991;78(6):651-5. http://
dx.doi.org/10.1002/bjs.1800780607
6. Fantini GA, Conte MS. Pulmonary failure following lower torso
ischemia: clinical evidence for a remote effect of reperfusion injury.
Am Surg. 1995;61(4):316-9.
7. Takhtfooladi H, Takhtfooladi M, Moayer F, Mobarakeh S. Melatonin
attenuates lung injury in a hind limb ischemia-reperfusion rat model.
Rev Port Pneumol (2006). 2015;21(1):30-5. http://dx.doi.org/10.1016/j.
rppnen.2014.01.010
8. Takhtfooladi MA, Jahanshahi A, Sotoudeh A, Jahanshahi G,
Takhtfooladi HA, Aslani K. Effect of tramadol on lung injury induced
by skeletal muscle ischemia-reperfusion: an experimental study. J
Bras Pneumol. 2013;39(4):434-9. http://dx.doi.org/10.1590/S1806-
37132013000400006
9. Sotoudeh A, Takhtfooladi MA, Jahanshahi A, Asl AH, Takhtfooladi
HA, Khansari M. Effect of N-acetylcysteine on lung injury induced by
skeletal muscle ischemia-reperfusion. Histopathological study in rat
model. Acta Cir Bras. 2012;27(2):168-71. http://dx.doi.org/10.1590/
S0102-86502012000200012
10. Nitescu N, Ricksten SE, Marcussen N, Haraldsson B, Nilsson U,
Basu S, et al. N-acetylcysteine attenuates kidney injury in rats
subjected to renal ischaemia reperfusion. Nephrol Dial Transplant.
2006;21(5):1240-7. http://dx.doi.org/10.1093/ndt/gfk032
11. Okumura AS, Rodrigues LE, Martinelli R. Pentoxifylline in ischemia-
induced acute kidney injury in rats. Ren Fail. 2009;31(9):829-32. http://
dx.doi.org/10.3109/08860220903137509
12. Lin SL, Chen YM, Chiang WC, Wu KD, Tsai TJ. Effect of pentoxifylline
in addition to losartan on proteinuria and GFR in CKD: A 12-month
randomized trial. Am J Kidney Dis. 2008;52(3):464-74. http://dx.doi.
org/10.1053/j.ajkd.2008.05.012
13. Yildirim Z, Kotuk M, Erdogan H, Iraz M, Yagmurca M, Kuku I, et al.
Preventive effect of melatonin on bleomycin-induced lung brosis in
rats. J Pineal Res. 2006;40(1):27-33. http://dx.doi.org/10.1111/j.1600-
079X.2005.00272.x
14. Yagi K. Lipid peroxides and related radicals in clinical medicine.
In: Armstrong D, editor. Free radicals in diagnostic medicine. A
systems approach to laboratory technology, clinical correlations, and
antioxidant therapy. New York: Plenum Press; 1994. p. 1-15. http://
dx.doi.org/10.1007/978-1-4615-1833-4_1
15. Winterbourn CC, Hawkins RE, Brian M, Carrell RW. The estimation of
red cell superoxide dismutase activity. J Lab Clin Med. 1975;85(2):337-41.
16. ELLMAN GL. Tissue sulfhydryl groups. Arch Biochem Biophys.
1959;82(1):70-7. http://dx.doi.org/10.1016/0003-9861(59)90090-6
17. Koksel O, Yildirim C, Cinel L, Tamer L, Ozdulger A, Bastürk M, et
al. Inhibition of poly(ADP-ribose) polymerase attenuates lung tissue
damage after hind limb ischemia-reperfusion in rats. Pharmacol Res.
2005;51(5):453-62. http://dx.doi.org/10.1016/j.phrs.2004.11.007
18. Schoenberg MH, Beger HG. Reperfusion injury after intestinal
ischemia. Crit Care Med. 1993;21(9):1376-86. http://dx.doi.
org/10.1097/00003246-199309000-00023
19. Toyokuni S. Reactive oxygen species-induced molecular damage
and its application in pathology. Pathol Int. 1999;49(2):91-102. http://
dx.doi.org/10.1046/j.1440-1827.1999.00829.x
20. Brivida K, Sies H. Non-enzymatic antioxidant defense system. In
Frei B, editor. Natural antioxidants in human health and disease. San
Diego: Academic Press; 1994. p. 107-28.
21. de Zwart LL, Meerman JH, Commandeur JN, Vermeulen NP.
Biomarkers of free radical damage applications in experimental
animals and in humans. Free Radic Biol Med. 1999;26(1-2):202-26.
http://dx.doi.org/10.1016/S0891-5849(98)00196-8
22. Holdiness MR. Clinical pharmacokinetics of N-acetylcysteine.
Clin Pharmacokinet. 1991;20(2):123-134. http://dx.doi.
org/10.2165/00003088-199120020-00004
23. Takhtfooladi MA, Jahanshahi A, Sotoudeh A, Daneshi MH, Khansari
M, Takhtfooladi HA. The antioxidant role of N-acetylcysteine on the
testicular remote injury after skeletal muscle ischemia and reperfusion
in rats. Pol J Pathol. 2013;64(3):204-9. http://dx.doi.org/10.5114/
pjp.2013.38140
24. Aruoma OI, Halliwell B, Hoey BM, Butler J. The antioxidant action
of N-acetylcysteine: its reaction with hydrogen peroxide, hydroxyl
radical, superoxide, and hypochlorous acid. Free Radic Biol Med.
1989;6(6):593-7. http://dx.doi.org/10.1016/0891-5849(89)90066-X
25. Cuzzocrea S, Mazzon E, Costantino G, Serraino I, De Sarro A, Caputi
AP. Effects of n-acetylcysteine in a rat model of ischemia and
reperfusion injury. Cardiovasc Res. 2000;47(3):537-48. http://dx.doi.
org/10.1016/S0008-6363(00)00018-3
26. Sehirli AO, Sener G, Satiroglu H, Ayanoğlu-Dülger G. Protective effect
of N-acetylcysteine on renal ischemia/reperfusion injury in the rat. J
Nephrol. 2003;16(1):75-80.
27. DiMari J, Megyesi J, Udvarhelyi N, Price P, Davis R, Sarstein R.
N-acetyl cysteine ameliorates ischemic renal failure. Am J Physiol.
1997;272(3 Pt 2):292-8.
28. Da Silveira M, Yoshida WB. Trimetazidine and N-acetylcysteine in
attenuating hind-limb ischemia and reperfusion injuries: experimental
study in rats. Int Angiol. 2009;28(5):412-7.
29. Shimizu MH, Danilovic A, Andrade L, Volpini RA, Libório AB,
Sanches TR, et al. N-acetylcysteine protects against renal injury
following bilateral ureteral obstruction. Nephrol Dial Transplant.
2008;23(10):3067-73. http://dx.doi.org/10.1093/ndt/gfn237
30. Stafford-Smith M. Evidence-based renal protection in cardiac surgery.
Semin Cardiothorac Vasc Anesth. 2005;9(1):65-76. http://dx.doi.
org/10.1177/108925320500900107
31. Emrecan B, Tulukoglu E, Bozok S, Kestelli M, Onem G, Küpelioglu
A, et al. Effects of lloprost and pentoxifylline on renal ischemia-
reperfusion in rabbit model. Eur J Med Res. 2006;11(7):295-9.
32. Dávila-Esqueda ME, Martinez-Morales F. Pentoxifylline diminishes
the oxidative damage to renal tissue induced by streptozotocin
in the rat. Exp Diabesity Res. 2004;5(4):245-51. http://dx.doi.
org/10.1080/154386090897974
13
J Bras Pneumol. 2016;42(1):9-14