Changes in Thyroid Function Associated With Pregnancy in Golden Hamsters

Date of Graduation

Summer 1992

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Thomas Tomasi

Abstract

Thyroxine (T₄) and triiodothyronine (T₃) utilization rates were calculated to determine the changes in thyroid function during pregnancy in the hamster, (Mesocricetus auratus). Turnover rates were calculated via the plasma disappearance technique using ¹²⁵I-labeled hormones. Serum T₄ and T₃ were measured by RIA. Measurements were made before pregnancy and on gestational days 1, 7, and 13. The T₄ utilization increased (p < 0.05) tenfold during the latter part of pregnancy, apparently due to an elevated volume of T₄ distribution. Serum T₄ levels did not change. Triiodothyronine utilization did not change during pregnancy, but T₃ levels decreased middle to late pregnancy. A lower level of T₃ entering the tissues in the latter part of pregnancy seems to be an energy-conserving adaptation in this species.

Subject Categories

Biology

Copyright

© Lisa Harmon Walker

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Dissertation/Thesis

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