Differential gene expression, with its precise start and stop times, is believed to be critical for the programmed development of new cells and tissues. Within the developing fetus, one tissue of particular interest is fetal liver. This organ undergoes rapid changes in the pathway toward liver development in utero since it is also the major site of hematopoiesis, until bone marrow hematopoiesis...

Fetal physiologists have centered their attention on the endocrine system when considering the potential interaction of one fetal organ with another or one fetal organ with the placenta. Our own studies in pregnant sheep showed an impressive correlation between placental size and the size of the fetal liver (Fig. 1). This observation—which is not a characteristic of the fetal brain, for example...

PURPOSE To examine the feasibility of using MRI to identify differences in liver size and fat deposition in fetal guinea pigs exposed to an in utero environment influenced by maternal consumption of a Western diet. MATERIALS AND METHODS Female guinea pigs fed either an energy-dense Western Diet (WD), comprised of increased saturated fats and simple sugars, or a Control Diet (CD) from weaning ...

The developmental and tissue-specific regulation of growth hormone receptor (GHR) mRNA expression is complex and involves alternate leader exon usage. The transcript composition of hepatic GHR mRNA has therefore been determined in fetal sheep during late gestation and after experimental manipulation of fetal plasma cortisol levels by fetal adrenalectomy and exogenous cortisol infusion, using RN...

This study investigates the in vivo dose response profiles of the target enzyme cholinesterase (ChE) and the detoxifying enzymes carboxylesterase (CaE) in the fetal and maternal compartments of pregnant rats dosed with chlorpyrifos [(O,O'-diethyl O-3,5,6-trichloro-2-pyridyl) phosphorothionate], a commonly used organophosphorus insecticide. Pregnant rats were dosed daily (po) with chlorpyrifos i...

This article describes the isolation of a novel cell population (B220(lo)c-kit(+)CD19(-)) in the fetal liver that represents 70% of T-cell precursors in this organ. Interestingly, these precursors showed a bipotent T-cell and natural killer cell (NK)- restricted reconstitution potential but completely lacked B and erythromyeloid differentiation capacity both in vivo and in vitro. Moreover, not ...

Previously we showed that the ~2% of fetal liver cells reactive with an anti-CD3epsilon monoclonal antibody support ex vivo expansion of both fetal liver and bone marrow hematopoietic stem cells (HSCs); these cells express two proteins important for HSC ex vivo expansion, IGF2, and angiopoietin-like 3. Here we show that these cells do not express any CD3 protein and are not T cells; rather, we ...

Reduced maternal glucose supply to the fetus and resulting fetal hypoglycemia and hypoinsulinemia activate fetal glucose production as a means to maintain cellular glucose uptake. However, this early activation of fetal glucose production may be accompanied by hepatic insulin resistance. We tested the capacity of a physiological increase in insulin to suppress fetal hepatic gluconeogenic gene a...

Comparative measurements of different types of hematopoietic progenitors present in human fetal liver, cord blood, and adult marrow showed a large (up to 250-fold), stage-specific, but lineage-unrestricted, amplification of the colony-forming cell (CFC) compartment in the fetal liver, with a higher ratio of all types of CFC to long-term culture-initiating cells (LTC-IC) and a lower ratio of tot...

In previous investigations, we have found that the liver appears to be the major source of cholesterol in the human fetus, and, in particular, a principal source of circulating low density lipo-protein-cholesterol (LDL-C). LDL-C plasma levels are low in the normal fetus, most likely due to the rapid uptake and metabolism by the fetal adrenal as precursor for steroid hormone biosynthesis. In con...