Protection effect of taurine on nitrosative stress in the mice brain with chronic exposure to arsenic.
BACKGROUND
Arsenic exposure induces overproduction of reactive nitrogen species (RNS) in brain tissue and results in nucleic acid damage to the nerve cells. The 8-nitroguanine is one of the major products formed by the reaction of guanine, and ONOO-, and has been used as a popular biomarker of nucleic acid damage due to RNS attacking. In the present study, we examined whether the administration of taurine can protect against nucleic acid damage of brain neurons by arsenic-induced RNS.


METHODS
Sixty mice (30 male and 30 female) weighing 19.5 +/- 1.5 g were divided into 3 groups: (1) control group, (2) experimental group that received arsenic (As2O3), and (3) antagonistic group that received taurine with arsenic. Arsenic was administered for 60 days. 8-Nitroguanine expressions in brain neurons of mice were examined by the immunohistochemical method. Histopathological changes in brain tissues of mice were observed under light microscope and the immunohistochemistry method was used to investigate 8-nitroguanine expressions in cerebrum and cerebellum of mice.


RESULTS
In the control group, no abnormal histopathological changes were observed in brain tissue of the mice. In brain tissue of the mice exposed to arsenic, histopathological results showed swells, evident vacuolar degeneration in cytoplasm, karyorrhexis and karyolysis. Relatively light pathological changes were observed in brain of the mice co-administered arsenic and taurine. Little or no expression of 8-nitroguanine in brain tissue was observed in controls. However, intensive expression of 8-nitroguanine was found in brain tissue of mice exposed to arsenic and it was mainly distributed in nucleus neighbouring the nuclear membrane, but a little in cytoplasm. A weak expression of 8-nitroguanine was observed in brain cells of mice co-administered arsenic and taurine.


CONCLUSIONS
The brain neurons may be the major target cells of arsenic neurotoxicity. Co-administration of arsenic and taurine can alleviate DNA damage of brain neurons caused by arsenic through the RNS signal pathway.
Ma
Ning
N
Faculty of Health Science and Institute of Traditional Chinese Medicine, Suzuka University of Medical Science, Suzuka, Mie 510-0293, Japan. maning@suzuka-u.ac.jp
Sasoh
Mikio
M
Kawanishi
Shosuke
S
Sugiura
Hiromichi
H
Piao
Fengyuan
F
D000818:Animals; D000077237:Arsenic Trioxide; D001152:Arsenicals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010087:Oxides / Q000633:toxicity*; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D013654:Taurine / Q000494:pharmacology*
C095838:8-nitroguanine; D001152:Arsenicals; D018696:Neuroprotective Agents; D010087:Oxides; D026361:Reactive Nitrogen Species; D013654:Taurine; D006147:Guanine; D000077237:Arsenic Trioxide
Kathmandu Univ Med J (KUMJ). 2008 Jan-Mar;6(1):60-9
18604117
Antioxid Redox Signal. 2006 May-Jun;8(5-6):1047-58
16771694
Nitric Oxide. 2004 Sep;11(2):175-83
15491850
Free Radic Biol Med. 2008 Oct 15;45(8):1065-72
18621123
Indian J Biochem Biophys. 1999 Feb;36(1):51-4
10549161
J Histochem Cytochem. 1994 May;42(5):621-6
7908911
Indian J Physiol Pharmacol. 1998 Oct;42(4):440-52
10874342
Neurotoxicol Teratol. 2002 Nov-Dec;24(6):743-50
12460656
Toxicology. 2007 May 5;234(1-2):10-20
17374429
Clin Exp Immunol. 2008 Apr;152(1):102-10
18241224
Adv Exp Med Biol. 2009;643:463-72
19239178
Toxicol Lett. 2002 Mar 10;128(1-3):69-72
11869818
Rev Environ Health. 1999 Oct-Dec;14(4):211-29
10746734
J Toxicol Clin Toxicol. 2001;39(7):675-82
11778665
Biol Chem. 2006 Apr;387(4):365-72
16606333
Toxicol Lett. 2009 Jan 30;184(2):121-5
19041379
Mutat Res. 2003 Dec 10;533(1-2):173-82
14643419
Neurobiol Dis. 2006 Jun;22(3):669-76
16624563
Postgrad Med J. 2003 Jul;79(933):391-6
12897217
Brain Res. 2008 Nov 6;1239:226-34
18801346
Environ Health Perspect. 2001 Jun;109(6):629-31
11445518
Arch Physiol Biochem. 2001 Feb;109(1):90-4
11471076
Carcinogenesis. 2004 Aug;25(8):1535-42
15059927
Amino Acids. 2000;19(3-4):509-26
11140356
J Occup Health. 2005 Sep;47(5):445-9
16230839
Toxicol Ind Health. 2008 May;24(4):247-56
19022878