# ABSORPTION AND METABOLISM OF CAROTENOIDS

> **NIH NIH R01** · GEORGE WASHINGTON UNIVERSITY · 1993 · $132,524

## Abstract

In view of the growing evidences for the anticarcinogenic actions of
carotenoids per se,a clear understanding of the mechanism of absorption,
metabolism and distribution of carotenoids is essential. Recent studies
including ours strongly support that ferret may be a suitable model for
carotenoid research since it can absorb substantial amounts of intact
beta-carotene just like humans. Therefore, it is proposed to carry out the
proposed studies using ferret as the experimental animal model.
Preferential localization of carotenoids in specific susceptible organs
may protect against malignancy. The possibility of the formation of
products other than retinal from the cleavage of beta-carotene in vivo and
in vitro should be investigated because some of these carotenoid products
may possess greater anticarcinogenic properties. It is important to prove
whether or not retinal is the obligatory intermediate in the formation of
retinoids from beta-carotene and to pinpoint the role of CRBP II in these
processes. It is equally important to characterize a specific protein
complex for beta-carotene inside the cell and for its transport.

The experimental approaches described should help to accomplish the
following specific aims using ferret as the experimental animal model:

1. To increase the absorption and distribution of beta-carotene in various
organs.

2. To test the dietary inducibility of beta-carotene cleavage (BCC)
enzyme.

3. To correlate the in vivo products of beta-carotene metabolism with
those in vitro.

4. To prove unequivocally whether or not retinal is a normal intermediate
during the conversion of beta-carotene into retinol and retinoic acid
using the BCC enzyme.

5. To define the roles of CRBP II in the conversion of beta-carotene to
retinoids using the BCC enzyme.

6. To identify a specific protein which forms a complex with beta-carotene
for its transport and storage.

The PI has expertise in the following systems and techniques to accomplish
these specific aims: 1. Thoracic duct cannulation technique to
quantitatively recover the products of beta-carotene cleavage. 2. HPLC
procedures for separation and identification of various metabolites of
beta-carotene. 3. Scanning spectrophotometry for characterization of
carotenoids and retinoids. 5. Centrifugal elutriation and discontinuous
gradient methods for purification of liver cells. 6. Ultracentrifugation,
ion-exchange, gel- filtration and affinity column chromatography and gel
electrophoretic techniques for the characterization of beta-carotene-
protein complex.

## Key facts

- **NIH application ID:** 3179415
- **Project number:** 2R01CA039999-04A4
- **Recipient organization:** GEORGE WASHINGTON UNIVERSITY
- **SAM.gov UEI:** ECR5E2LU5BL6
- **Principal Investigator:** RAJ M LAKSHMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $132,524
- **Award type:** 2
- **Project period:** 1987-04-01 → 1996-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3179415

## Citation

> US National Institutes of Health, RePORTER application 3179415, ABSORPTION AND METABOLISM OF CAROTENOIDS (2R01CA039999-04A4). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3179415. Licensed CC0.

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