Thyroid hormones in human follicular fluid and thyroid hormone receptors in human granulosa cells

Abstract

Objective: To demonstrate the presence of thyroid hormone in human follicular fluid (FF) and the binding of antithyroid hormone antibodies in human granulosa cells (GCs).

Design: Follicular fluids and GCs collected from women undergoing oocyte retrieval after superovulation.

Setting: In Vitro Fertilization-America/Allegheny General Hospital and Reproductive Sciences Research Laboratories, the Department of Obstetrics and Gynecology, The Medical College of Pennsylvania/Allegheny Campus.

Main outcome measures: Follicular fluid levels of triiodothyronine (T3) determined by a microparticle enzyme immunoassay and FF levels of thyroxine (T4) determined by a fluorescence polarization immunoassay. Three anti-thyroid receptor antibodies were used to determine the presence of thyroid receptor. The binding of these antibodies in GCs was assessed by fluorescent microscopy and flow cytometry.

Results: Both T3 and T4 were present in the FF of eight patients studied. A large majority of the samples of individual fluids fell within the normal range for serum. There was a positive correlation between serum T4 values and FF T4 values. The three antithyroid receptor antibodies showed positive nuclear staining of GCs by fluorescent microscopy. The antibody to all thyroid hormone receptors yielded 35% positive cells by flow cytometry, and the site specific antibody for either the alpha-1 or beta-1 receptors yielded 78% and 44% positive cells, respectively.

Conclusion: These data demonstrated, for the first time, the presence of T3 and T4 in human FF and the presence of T3 binding sites in human GCs and suggest a role for thyroid hormone in the regulation of human GCs.