کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5519444 1544112 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of exposure to microcystin-LR at environmentally relevant concentrations on the metabolism of thyroid hormones in adult zebrafish (Danio rerio)
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیوشیمی، ژنتیک و زیست شناسی مولکولی (عمومی)
پیش نمایش صفحه اول مقاله
Effects of exposure to microcystin-LR at environmentally relevant concentrations on the metabolism of thyroid hormones in adult zebrafish (Danio rerio)
چکیده انگلیسی


- MC-LR disturbed either the gene transcription or T3 levels in adult zebrafish.
- MC-LR did not inhibit the production of TH in adult zebrafish.
- The effect of MC-LR on ID activities might contribute to the changes of T3 levels.
- The zebrafish can trigger a compensatory mechanism to maintain TH homeostasis.

Microcystin-LR (MC-LR) has the potential to disturb thyroid hormone homeostasis. However, the effects of MC-LR at environmentally relevant concentrations on the thyroid system in adult fish are still unclear. In this study, adult zebrafish were exposed to 0, 1, 5, and 25 μg/L MC-LR for 7, 14, 21, and 28 days. Whole-body thyroid hormones (THs) levels and thyroid follicle histology were used to assess thyroid function. The transcription of corticotropin-releasing hormone (crh), thyroid-stimulating hormone (tsh), transthyretin (ttr), thyroid hormone receptors (trs) genes, and the activities of iodothyronine deiodinases (IDs) were investigated to study the process of TH metabolism disruption. No differences in the histopathology of thyroid follicles and unchanged T4 levels were observed in adult zebrafish. A significant decline in T3 levels associated with a decrease in ID2 activity in male zebrafish was observed at 21 days exposure. Moreover, the mRNA expression of tsh, ttr and trs appeared to be a dynamic process as expression first decreased and then increased with continued exposure. These results indicated that exposure to MC-LR did not inhibit the production of TH. The decrease in ID2 activity may be an important factor in the decline of T3 levels. Furthermore, it seems that the fish triggered a compensatory mechanism to maintain TH homeostasis in respond to environmental concentrations of MC-LR which induced TH disruption.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Toxicon - Volume 124, 15 December 2016, Pages 15-25
نویسندگان
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