کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1990773 | 1540702 | 2010 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular mechanisms involved in the enhancement of mitochondrial malate dehydrogenase activity by calcitriol in chick intestine
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Mitochondrial malate dehydrogenase (mMDH) from the intestine is the NAD-linked oxidoreductase of the tricarboxylic acid cycle with the highest activity and response to vitamin D treatment in vitamin D-deficient chicks (âD). The aim of this study was to elucidate potential molecular mechanisms by which cholecalciferol or calcitriol enhances the activity of this enzyme. One group of animals used was composed of âD and âD treated with cholecalciferol or with calcitriol. A second group consisted of âD and âD supplemented with high Ca2+ diet. A third group included chicks receiving either a normal or a low Ca2+ diet. In some experiments, animals were injected with cycloheximide. Data showed that either vitamin D (cholecalciferol or calcitriol) or a low Ca2+ diet increases mMDH activity. High Ca2+ diet did not modify the intestinal mMDH activity from âD. The mMDH activity from âD remained unaltered when duodenal cells were exposed to 10â8 mol/L calcitriol for 15 min. The enhancement of mMDH activity by calcitriol was completely abolished by simultaneous cycloheximide injection to âD. mMDH mRNA levels, detected by RT-PCR, indicate that calcitriol did not affect gene expression. In contrast, Western blots show that calcitriol enhanced the protein expression. In conclusion, calcitriol stimulates intestinal mMDH activity by increasing protein synthesis. No response of mMDH activity by rapid effects of calcitriol or activation through increment of serum Ca2+ was demonstrated. Consequently, ATP production would be increased, facilitating the Ca2+ exit from the enterocytes via the Ca2+-ATPase and Na+/Ca2+ exchanger, which participate in the intestinal Ca2+ absorption.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Nutritional Biochemistry - Volume 21, Issue 12, December 2010, Pages 1232-1237
Journal: The Journal of Nutritional Biochemistry - Volume 21, Issue 12, December 2010, Pages 1232-1237
نویسندگان
Adriana Pérez, Viviana A. Centeno, Nori G. Tolosa de Talamoni,