Traversing barriers - How thyroid hormones pass placental, blood-brain and blood-cerebrospinal fluid barriers.
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.
Conjoint Endocrine Laboratory, Chemical Pathology, Pathology Queensland, Queensland Health, Herston, Qld 4029, Australia.
Kelly
K
Landers
Conjoint Endocrine Laboratory, Chemical Pathology, Pathology Queensland, Queensland Health, Herston, Qld 4029, Australia; School of Medicine, University of Queensland, Herston, Qld 4029, Australia; School of Biomedical Sciences, Queensland University of Technology, Brisbane, Qld 4000, Australia. Electronic address: kerry.richard@qimrberghofer.edu.au.
Kerry
K
Richard
D001812:Blood-Brain Barrier / Q000378:metabolism; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D005260:Female; D047109:Fetal Development; D006801:Humans; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D021381:Protein Transport; D013963:Thyroid Hormones / Q000134:cerebrospinal fluid / Q000378:metabolism*
D013963:Thyroid Hormones
Blood-cerebrospinal fluid barrier; Blood–brain barrier; Brain; Placenta; Thyroid hormone