کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9478349 | 1324796 | 2005 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Plasma concentrations of estradiol and testosterone, gonadal aromatase activity and ultrastructure of the testis in Xenopus laevis exposed to estradiol or atrazine
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم آبزیان
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Plasma concentrations of estradiol and testosterone, gonadal aromatase activity and ultrastructure of the testis in Xenopus laevis exposed to estradiol or atrazine Plasma concentrations of estradiol and testosterone, gonadal aromatase activity and ultrastructure of the testis in Xenopus laevis exposed to estradiol or atrazine](/preview/png/9478349.png)
چکیده انگلیسی
The ultrastructure of testicular cells of adult male African clawed frogs (Xenopus laevis) exposed to either estradiol (0.1 μg/L) or 2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine (atrazine; 10 or 100 μg/L) was examined by electron microscopy and compared to plasma concentrations of the steroid hormones, testosterone (T) and estradiol (E2), testicular aromatase activity and gonad growth expressed as the gonado-somatic index (GSI). Exposure to E2 caused significant changes both at the sub-cellular and biochemical levels. Exposure to E2 resulted in significantly fewer sperm cells, inhibition of meiotic division of germ cells, more lipid droplets that are storage compartments for the sex steroid hormone precursor cholesterol, and lesser plasma T concentrations. Although not statistically significant, frogs exposed to E2 had slightly smaller GSI values. These results may be indicative of an inhibition of gonad growth and disrupted germ cell development by E2. Concentrations of E2 in plasma were greater in frogs exposed to E2 in water. Exposure to neither concentration of atrazine caused effects on germ cell development, testicular aromatase activity or plasma hormone concentrations. These results suggest that atrazine does not affect testicular function. In contrast, exposure of male X. laevis to E2 led to sub-cellular events that are indicative of disruption of testicular development, and demasculinization processes (decrease of androgen hormone titers). These results indicate that atrazine does not cause responses that are similar to those caused by exposure to E2.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Aquatic Toxicology - Volume 72, Issue 4, 15 May 2005, Pages 383-396
Journal: Aquatic Toxicology - Volume 72, Issue 4, 15 May 2005, Pages 383-396
نویسندگان
Markus Hecker, Wan Jong Kim, June-Woo Park, Margaret B. Murphy, Daniel Villeneuve, Katherine K. Coady, Paul D. Jones, Keith R. Solomon, Glen Van Der Kraak, James A. Carr, Ernest E. Smith, Louis du Preez, Ronald J. Kendall, John P. Giesy,