Premium
Response of anti‐oxidant enzymes mRNA in the neonatal rat liver exposed to 1,2,3,4‐tetrachlorodibenzo‐ p ‐dioxin via lactation
Author(s) -
Kono Yumi,
Okada Shin’ichi,
Tazawa Yusaku,
Kanzaki Susumu,
Mura Tetsuo,
Ueta Etsuko,
Nanba Eiji,
Otsuka Yuzuru
Publication year - 2002
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1046/j.1442-200x.2002.01608.x
Subject(s) - glutathione peroxidase , superoxide dismutase , medicine , endocrinology , lactation , catalase , antioxidant , oxidative stress , dismutase , andrology , biology , biochemistry , pregnancy , genetics
Background: The aim of this study was to assess the response to dioxin‐induced oxidative stress in neonates via lactation in the model we have described previously.Methods: Maternal rats were treated with a single dose of 50 or 100 µmol/kg 1,2,3,4‐tetrachlorodibenzo‐ p ‐dioxin (TCDD) on the first day postpartum (day 1). Messenger RNA levels of the key anti‐oxidant enzymes (AOE), phospholipid hydroperoxide‐glutathione peroxidase (PH‐GPx), cellular‐glutathione peroxidase (cell‐GPx), copper‐zinc superoxide dismutase (CuZn SOD), manganese superoxide dismutase (Mn SOD) and catalase (CAT) in the neonatal and maternal livers were determined by a competitive reverse transcription− polymerase chain reaction method.Results: Lactational transfer of 1,2,3,4‐TCDD induced an inhibition of PH‐GPx and cell‐GPx mRNA in the neonatal liver on day 2 to 68 ( P < 0.01) and 62% ( P < 0.05) of the control at 100 µmol/kg, respectively. Both GPx mRNA returned to control levels on day 6 and thereafter increased to levels higher than the controls on day 10. In the dam rat, 10 days after the treatment, no remarkable change of PH‐GPx or cell‐GPx mRNA was observed. Copper‐zinc superoxide dismutase and CAT mRNA of neonates on day 2 were also suppressed at 100 µmol/kg and then slightly increased on day 10. However, Mn SOD mRNA was not suppressed, but increased to a 2.1‐fold level of the control ( P < 0.05) on day 10 with 100 µmol/kg 1,2,3,4‐TCDD.Conclusion: Quantitative analysis of AOE mRNA showed that PH‐GPx and cell‐GPx mRNA, as well as CuZn SOD and CAT mRNA in the neonatal liver were suppressed for a short period of time by 1,2,3,4‐TCDD exposure via lactation. Dioxin induced oxidative stress by lactational transfer may alter pretranslation regulation of protective AOE in neonates.