Vitellogenin association and oocytic accumulation of thyroxine and 3, 5,3'-triiodothyronine in gravid Fundulus heteroclitus.

Journal Article (Journal Article)

The association of the thyroid hormone (TH) thyroxine (T(4)) and its metabolically active metabolite 3,5,3'-triiodothyronine (T(3)) with serum vitellogenin (VTG) in gravid female and estrogenized male (E2+) Fundulus heteroclitus was investigated. In in vivo, time-course experiments, sera from gravid female fish exposed to [(125)I]T(4) showed time- and dose-dependent increases in total [(125)I]TH content. The [(125)I]T(4):[(125)I]T(3) ratio was also affected by dose and time. In analysis of sera from female fish, >80% of detected radioactivity was associated with VTG (approximately 35%) and a second chromatographic peak (approximately 45%), a lipoprotein fraction possibly consisting of high-density lipoproteins. In experiments comparing estrogenized versus control male fish, the presence of VTG significantly increased the overall quantity and altered the profile of serum protein-associated [(125)I]TH. When serum VTG was present in the very large quantities typical of male fish treated with high doses of E2, the majority (59-70%) of detected radioactivity was associated with VTG. Both [(125)I]T(4) and [(125)I]T(3) were detected in extracts from oocytes collected during the in vivo female study. The total TH content and [(125)I]T(4):[(125)I]T(3) ratios in these extracts presented an accumulation profile that mirrored, in a delayed manner, the profiles observed in sera data. Furthermore, this accumulation was related to oocyte maturational state (i.e., size) and, correspondingly, VTG uptake. Together, these data suggest an important role for VTG as a vector of maternal transfer for both T(4) and T(3).

Full Text

Duke Authors

Cited Authors

  • Monteverdi, GH; Di Giulio, RT

Published Date

  • November 2000

Published In

Volume / Issue

  • 120 / 2

Start / End Page

  • 198 - 211

PubMed ID

  • 11078631

Electronic International Standard Serial Number (EISSN)

  • 1095-6840

International Standard Serial Number (ISSN)

  • 0016-6480

Digital Object Identifier (DOI)

  • 10.1006/gcen.2000.7551


  • eng