Skip Navigation



ToxSci Advance Access published online on June 14, 2008
Toxicological Sciences, doi:10.1093/toxsci/kfn119
This Article
Right arrow Advance Access manuscript (PDF) Freely available
Right arrow All Versions of this Article:
105/1/51    most recent
kfn119v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Sharma, B.
Right arrow Articles by Patiño, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sharma, B.
Right arrow Articles by Patiño, R.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Published by Oxford University Press 2008.

Exposure of Xenopus laevis Tadpoles to Cadmium Reveals Concentration-dependent Bimodal Effects on Growth and Monotonic Effects on Development and Thyroid Gland Activity

Bibek Sharma* and Reynaldo Patiño{dagger},{ddagger}

* Department of Natural Resources Management, Texas Tech University, Lubbock, Texas 79409-2125 {dagger} USGS Texas Cooperative Fish and Wildlife Research Unit, Texas Tech University, Lubbock, Texas 79409-2120

{ddagger} To whom correspondence should be addressed Reynaldo Patiño, USGS Texas Cooperative Fish & Wildlife Research Unit, Texas Tech University, Lubbock, TX 79409-2120, USA, Phone: 806-742-2851 ; Fax: 806-742-2946 ; E-mail: reynaldo.patino{at}ttu.edu

Received March 7, 2008; revision received May 14, 2008; accepted June 10, 2008


  Abstract

Xenopus laevis were exposed to 0-855 µg cadmium (Cd)/l (measured concentrations) in FETAX medium from fertilization to 47 days post fertilization. Measurements included embryonic survival and, at 47 days, tadpole survival, snout-vent length, tail length, total length, hindlimb length, weight, Nieuwkoop-Faber (NF) stage of development, initiation of metamorphic climax (≥ NF 58), and thyroid follicle cell height. Embryonic and larval survival were unaffected by Cd. Relative to control tadpoles, reduced tail and total length were observed at 0.1- 8 and at 855 µg Cd /l; and reduced snout-vent length, hindlimb length and weight were observed at 0.1-1 and at 855 µg Cd/l. Mean stage of development and rate of initiation of climax were unaffected by Cd at 0-84 µg/l; however, none of the tadpoles exposed to 855 µg Cd/l progressed beyond mid-premetamorphosis (NF 51). Thyroid glands with fully formed follicles were observed in all tadpoles ≥ NF 49 examined. Follicle cell height was unaffected by Cd at 0-84 µg/l but it was reduced at 855 µg/l; in the latter, cell height was reduced even when compared to NF 49-51 tadpoles pooled from the 0-84 µg Cd/l groups. In conclusion, (1) Cd affected tadpole growth in a bimodal pattern with the first and second inhibitory modes at concentrations below and above 84 µg Cd/l, respectively; (2) exposure to high Cd concentrations (855 µg/l) reduced thyroid activity and arrested tadpole development at mid-premetamorphosis; and (3) unlike its effect on growth, Cd inhibited tadpole development and thyroid function in a seemingly monotonic pattern.

Key Words: cadmium; growth; metamorphosis; thyroid; amphibian.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.