کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2598256 1562433 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Smoking specifically induces metallothionein-2 isoform in human placenta at term
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
پیش نمایش صفحه اول مقاله
Smoking specifically induces metallothionein-2 isoform in human placenta at term
چکیده انگلیسی

Recently, we reported the presence of higher levels of metallothionein (MT) in placentas of smokers compared to non-smokers. In the present study, we designed experiments to separate and evaluate two isoforms of MT (MT-1 and MT-2) in placentas of smokers and non-smokers. Metallothionein was extracted and separated by ion-exchange high performance liquid chromatography (HPLC), previous saturation with cadmium chloride. Two peaks eluting at 6 and 12.5 min, corresponding to MT-1 and MT-2, respectively, were obtained. Metallothionein present in both peaks was identified by Western blot analysis using a monoclonal antibody directed against MT-1 and MT-2. Each isoform concentration was calculated after measuring its cadmium content by atomic absorption spectrometry with inductively coupled-plasma. In placentas of smokers, MT-2 levels increased by seven-fold compared to non-smokers, whereas MT-1 was not changed. Total placental cadmium and zinc concentrations, determined by atomic absorption spectrometry and neutron activation analysis, respectively, were higher in smokers. Metallothioneins levels were clearly in excess to bind all cadmium ions present in placentas. However, most of placental zinc remains unbound to MTs, although as much as twice zinc ions could be bound to MT in smokers. In conclusion, MT-2 is the main isoform induced by smoking, suggesting that this isoform could be involved in placental cadmium and zinc retention. This fact, which could contribute to reduce the transference of zinc to the fetus, may be associated to detrimental effects on fetal growth and development.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Toxicology - Volume 223, Issues 1–2, 1 June 2006, Pages 46–53
نویسندگان
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