Evaluation of comparative effect of pre- and posttreatment of selenium on mercury-induced oxidative stress, histological alterations, and metallothionein mRNA expression in rats.
To evaluate the effect of pre- or posttreatment of selenium (6 micromol/kg b.w., single intraperitoneal injection) in mercury intoxication, rats were exposed to mercury (12 micromol/kg b.w., single intraperitoneal injection). Exposure to mercury resulted in induced oxidative stress in liver, kidney, and brain tissues. Marked changes in serum biochemical parameters together with alterations in histopathology and an induction in metallothionein-I and metallothionein-II mRNA expression in the liver and kidney were observed. Pretreatment with selenium to mercury-exposed animals had protective effect on the liver, whereas posttreatment had partial protection on restoration of altered oxidative stress parameters. In the kidney, pretreatment with selenium showed partial protection on restoration of altered biochemical parameters, whereas no protection was observed in posttreatment. The pretreatment with selenium resulted in restoration of mercury-induced metallothionein-I and metallothionein-II mRNA expression, which was completely restored in the liver whereas partial restoration was observed in the kidney. Posttreatment with selenium resulted in further induction in metallothionein-I and metallothionein-II mRNA expression in the liver and kidney. In the brain, selenium showed partial protection on alerted biochemical parameters. Results indicate that pretreatment with selenium is beneficial in comparison to posttreatment in mercury intoxication. Thus, dietary intake of selenium within safe limit may, therefore, enable us in combating any foreseen effects due to mercury exposure.
Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Council of Scientific and Industrial Research, India, Mahatma Gandhi Marg, Lucknow 226 001, India.
Rakhi
R
Agarwal
S
S
Raisuddin
Shikha
S
Tewari
Sudhir K
SK
Goel
R B
RB
Raizada
Jai Raj
JR
Behari
D000818:Animals; D002374:Catalase / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects / Q000235:genetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D008297:Male; D008628:Mercury / Q000378:metabolism / Q000633:toxicity*; D008668:Metallothionein / Q000235:genetics* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012643:Selenium / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
D012333:RNA, Messenger; D008668:Metallothionein; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D008628:Mercury; D005978:Glutathione; D012643:Selenium