Placenta. 2017 Jun;54:45-51. doi: 10.1016/j.placenta.2017.01.001. Epub 2017 Jan 4.
Review: Nutrient sulfate supply from mother to fetus: Placental adaptive responses during human and animal gestation.
Abstract
Nutrient sulfate
has numerous roles in mammalian physiology and is essential for healthy
fetal growth and development. The fetus has limited capacity to
generate sulfate and relies on sulfate supplied from the maternal circulation via placental sulfate transporters. The placenta also has a high sulfate requirement for numerous molecular and cellular functions, including sulfate
conjugation (sulfonation) to estrogen and thyroid hormone which leads
to their inactivation. Accordingly, the ratio of sulfonated (inactive)
to unconjugated (active) hormones modulates endocrine function in fetal,
placental and
maternal tissues. During pregnancy, there is a marked increase in the
expression of genes involved in transport and generation of sulfate in the mouse placenta, in line with increasing fetal and placental demands for sulfate. The maternal circulation also provides a vital reservoir of sulfate for the placenta and fetus, with maternal circulating sulfate
levels increasing by 2-fold from mid-gestation. However, despite
evidence from animal studies showing the requirement of maternal sulfate supply for placental and fetal physiology, there are no routine clinical measurements of sulfate or consideration of dietary sulfate
intake in pregnant women. This is also relevant to certain xenobiotics
or pharmacological drugs which when taken by the mother use significant
quantities of circulating sulfate for detoxification and clearance, and thereby have the potential to decrease sulfonation capacity in the placenta and fetus. This article will review the physiological adaptations of the placenta for maintaining sulfate homeostasis in the fetus and placenta, with a focus on pathophysiological outcomes in animal models of disturbed sulfate homeostasis.
Copyright © 2017 Elsevier Ltd. All rights reserved.
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