Molecular mechanisms of corticosteroid synergy with thyroid hormone during tadpole metamorphosis.

ABSTRACT: Corticosteroids (CS) act synergistically with thyroid hormone (TH) to accelerate amphibian metamorphosis. Earlier studies showed that CS increase nuclear 3,5,3'-triiodothyronine (T(3)) binding capacity in tadpole tail, and 5' deiodinase activity in tadpole tissues, increasing the generation of T(3) from thyroxine (T(4)). In the present study we investigated CS synergy with TH by analyzing expression of key genes involved in TH and CS signaling using tadpole tail explant cultures, prometamorphic tadpoles, and frog tissue culture cells (XTC-2 and XLT-15). Treatment of tail explants with T(3) at 100 nM, but not at 10 nM caused tail regression. Corticosterone (CORT) at three doses (100, 500 and 3400 nM) had no effect or increased tail size. T(3) at 10 nM plus CORT caused tails to regress simil

SUBMITTER: Bonett RM 

PROVIDER: S-EPMC2912948 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature