# VITAMIN A TRANSPORT SYSTEMS

> **NIH NIH R01** · VANDERBILT UNIVERSITY · 1993 · $155,732

## Abstract

The long-term goals of this project are to examine what factors
affect the regulation of the vitamin A transport systems and the
mechanism(s) by which such regulation is accomplished.  Of
particular interest for the proposed period are the specific
binding proteins and specific enzymes that are necessary for the
overall process of absorption of vitamin A.  These include cellular
retinol-binding protein, type two, (CRBP(II)), present in the small
intestine and cellular retinol-binding protein (CRBP), present in
the liver.  The enzymes in the gut of interest are the carotene-
cleavage enzyme, a microsomal retinal-reductase, and a microsomal
lecithinretinol acyl transferase.  A similar esterifying enzyme is
present in liver.  The work proposed will examine if these binding
proteins and enzyme activities are coordinately regulated in both
rat and human to ensure the efficient absorption of vitamin A.  In
rat, possible coordinate regulation will be examined 1) along the
horizontal (duodenumjejunum-ileum) and vertical (crypt-villus) axes
of the mature small intestine; 2) during development of the gut and
liver; 3) during pregnancy and lactation; 4) during the adaptation
of the small intestine that occurs after surgical resection or
transposition; and 5) under the influence of varying intakes of
vitamin A, as beta-carotene or retinyl ester.  In liver, particular
attention is given to a new ester synthase, lecithinretinol acyl
transferase, which will be purified.  Specific antiserum will be
produced to examine, by RIA and immunohistochemistry, its possible
cell-specific regulation in the parenchymal and stellate cells of
the liver during development and with varying intake of vitamin A.
Human CRBP(II) will be purified and used to define the vitamin A
absorptive system in human.  Particular attention will be given to
the very premature infant to determine if the elements necessary
for efficient absorption of vitamin A are being expressed.

## Key facts

- **NIH application ID:** 2199489
- **Project number:** 5R01HD025286-05
- **Recipient organization:** VANDERBILT UNIVERSITY
- **SAM.gov UEI:** GTNBNWXJ12D5
- **Principal Investigator:** DAVID E ONG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $155,732
- **Award type:** 5
- **Project period:** 1989-01-01 → 1994-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2199489

## Citation

> US National Institutes of Health, RePORTER application 2199489, VITAMIN A TRANSPORT SYSTEMS (5R01HD025286-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2199489. Licensed CC0.

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