Traversing barriers - How thyroid hormones pass placental, blood-brain and blood-cerebrospinal fluid barriers
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Updated: Mar 8, 2026

Author Spotlight: Modeling an Aspect of Preeclampsia in Female Mice Using Hypoxic Human Placenta-Derived Small Extracellular Vesicles
Published on: January 26, 2024
Kelly Landers1, Kerry Richard2
1Conjoint Endocrine Laboratory, Chemical Pathology, Pathology Queensland, Queensland Health, Herston, Qld 4029, Australia.
Abstract:
Thyroid hormone is essential for normal human fetal growth and brain development. As the fetal thyroid does not secrete thyroid hormones until about 18 weeks gestation, early fetal brain development depends on passage of maternal hormone across the placenta into the fetal circulation. To reach the fetal brain, maternally derived and endogenously produced thyroid hormone has to cross the blood-brain and blood-cerebrospinal fluid barriers. In this review we will discuss the complex biological barriers (involving membrane transporters, enzymes and distributor proteins) that must be overcome to ensure that the developing human brain has adequate exposure to thyroid hormone.
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