Transcript Protective effect of melatonin on thymus of rats exposed

PROTECTIVE EFFECT OF MELATONIN
ON THYMUS OF RATS EXPOSED TO
MICROWAVE RADIATION
Branka Djordjevic, Dusan Sokolovic, Andrej Veljkovic, Milena Marinkovic,
Jelena Basic , Gordana Kocic, Jelenka Nikolic
Department of Biochemistry, Faculty of Medicine, University of Nis.
Bul. dr Zorana Djindjica 81, 18000 Nis, Serbia
Microwaves
 300 GHz - 300 MHz
 1mm-1m
 1.24 µeV - 1.24 meV
Microwaves and oxidative stress
“Thymus plays an important role in the immune system
development...”
Matsui N, Nitta T, Takahama Y. Development of the thymus and immune system. Brain Nerve 2011;63(7):679-84.
“...which can be modulated by numerous environmental
factors, including MWs.”
Quaglino D, Capri M, Ronchetti IP. Modulation of cell death in the rat thymus. Light and electron microscopic
investigations. Ann N Y Acad Sci 2000;926:79-82.
“Oxidative stress has been implicated in thymus
disorders.“
Yan M, Shen J, Person MD, Kuang X, Lynn WS, Atlas D, et al. Endoplasmic reticulum stress and unfolded
protein response in Atm-deficient thymocytes and thymic lymphoma cells are attributable to oxidative stress.
Neoplasia. 2008;10(2):160-7.
 MWs have already been linked to cancer,
especially childhood leukemia and T cell
non Hodgkin lymphoma.
Myung SK, Ju W, McDonnell DD, Lee YJ, Kazinets G, Cheng CT, et al. Mobile phone
use and risk of tumors: a meta-analysis. J Clin Oncol 2009;27(33):5565-72.
Lowenthal RM, Tuck DM, Bray IC. Residential exposure to electric power transmission
lines and risk of lymphoproliferative and myeloproliferative disorders: a case-control
study. Intern Med J 2007; 37(9):614-9.
Melatonin
(N-acetyl-5-methoxytryptamine)
 sinthetised and released from pineal gland
 MT1 and MT2 receptors expressed in all lymphocyte
subpopulations
 immunostimulant and a powerfull antioxidant
 directly neutralizes free radicals
 stimulates antioxidant enzyme activity
 prevents oxidative injury of DNA molecules
 inhibits apoptosis in immune cells
Aim of the study
 The present study was designed to evaluate
the effects of MWs on oxidative stress
parametars in the thymus tissue and
 to clarify if melatonin treatment may
favorably impact on thymus tissue injury in
rats exposed to microwave radiation.
Experimental setup
 3-week daily administration of melatonin
(2 mg/kg i.p.)
 adult Wistar rats
 exposition to microwaves (4 hours/day)
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Wistar rats were divided in four groups:
I (control) - rats treated with saline,
II (Mel) - rats treated with melatonin,
III (MWs) - microwave exposed rats,
IV (MWs + Mel) - MWs exposed rats treated with
melatonin.
Exposure system
 plastic cage
 mobile phone (NOKIA 3110
classic, Nokia Mobile Phones
Ltd.)
 900 MHz electromagnetic near
field continuous wave
 AARONIA SPECTRAN HF6080
EMF meter
 SAR 0.089 W/kg
(0.043-0.135 W/kg)
Biochemical analysis
 Thymus tissue was prepared as 10% homogenate.
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Malondialdehyde (MDA)
Protein carbonyls
Catalase (CAT)
Xantine oxidase (XO)
Proteins
MDA
*** (p < 0.001)
+ (p < 0.05)
Ohkawa H, OhishiN, Yagi K. Assay for lipid peroxides
in animal tissues by thiobarbituric acid reaction. Anal
Biochem 1979;95(2):351-8.
Protein carbonyls
*** (p < 0.001)
+++ (p < 0.001)
Levine RL, WIilliams JA, Stadtman ER, et al. Carbonyl
assay for determination of oxidatively modified
proteins. Methods Enzymol 1994;233:346-57.
Catalase
*** (p < 0.001)
+++ (p < 0.001)
Goth L . A simple method for determination of serum
catalase activity and revision of reference range. Clin
Chim Acta 1991;196(2-3):143-51.
Xantine oxidase
*** (p < 0.001)
+++ (p < 0.001)
Hashimoto S. A new spectrophotometric assay method of
xanthine oxidase in crude tissue homogenate. Anal
Biochem 1974;62(2):426-35.
Conclusion
 Melatonin
exerts potent antioxidant
effects in thymus of rats exposed to
microwaves.
This work was supported by the Ministry of Education and
Science of Republic Serbia (Project 43012).
THANK YOU VERY MUCH
FOR YOUR KIND
ATTENTION!
Branka Djordjevic, Dusan Sokolovic, Andrej Veljkovic, Milena Marinkovic,
Jelena Basic , Gordana Kocic, Jelenka Nikolic
Department of Biochemistry, Faculty of Medicine, University of Nis.