# ION TRANSPORT IN THE PLACENTA

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 1994 · $180,221

## Abstract

The long term objectives of this study are to develop a model of the ion
transporting systems in the placental syncytiotrophoblast and to
investigate the involvement of ion transporters in the common
pathophysiologies of pregnancy.  The initial section of this project was
concerned with identifying and characterizing the major ion transporters in
the syncytiotrophoblast using microvillous and basal membrane vesicles
prepared from normal, term placenta.  This research has advanced to the
point that a change in the experimental approach is now necessary.  The
characterization of an individual transporter in membrane vesicle
establishes the potential activity of the transporter but does not provide
information on its integration into the cellular ion transport system, nor
determine the contribution it makes to specific cellular functions, and
does not describe the regulatory mechanisms operative in vivo.  It is
essential therefore to investigate the function of these transporters in a
cellular system.  The recently developed syncytiotrophoblast culture
provides the opportunity to study ion transport systems in the cellular
context.  A second and important aspect of the experimental approach to
this study is the use of high resolution, fluorescence microscopy,
employing ion-sensitive probes to measure intracellular ion concentrations.
The advent of this technique and the synthesis of new ion-specific
fluorescent probes provides the ability to examine rapid rates of change in
intracellular ion concentrations, repetitively and over extended time
periods.  The specific aims of the project during the next period are (1)
to continue investigation and characterization of individual transporters
using vesicles, looking particularly for those transporters which are
activated or regulated by nucleotide binding or phosphorylation; (2) to
determine the intracellular pH and intracellular concentrations of sodium,
potassium and chloride in resting syncytiotrophoblast; (3) to examine the
operation of ion transport systems which maintain ionic homeostasis,
provide for transcellular (transplacental) transport, regulate
intracellular pH and control cellular volume in the syncytiotrophoblast;
(4) to measure the effects of hypoxia on the time course of intracellular
ion concentrations in cultured syncytial cells, determining the
reversibility, effects on ion-coupled substrate transport and the
effectiveness of interventions designed to prolong cellular viability; (5)
to develop a new model for the investigation of ion transport, the
superfused, chorionic villous fragment which, when loaded with ion-specific
probes, will provide information on ion transport systems from primary
cells retaining their in vivo orientation and connections to other villous
tissue elements.  The ion transport systems to be investigated are the
essential core underlying a range of placental functions and knowledge of
these systems is crucial to our understanding of maternal-fetal
interaction. ...

## Key facts

- **NIH application ID:** 2198882
- **Project number:** 5R01HD023498-07
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **SAM.gov UEI:** KMH5K9V7S518
- **Principal Investigator:** Nicholas Illsley
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $180,221
- **Award type:** 5
- **Project period:** 1988-04-01 → 1996-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2198882

## Citation

> US National Institutes of Health, RePORTER application 2198882, ION TRANSPORT IN THE PLACENTA (5R01HD023498-07). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2198882. Licensed CC0.

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