Transfer of retinol from parenchymal to stellate cells in liver is mediated by retinol-binding protein

Journal Article · Sun May 01 00:00:00 EDT 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.10.3455· OSTI ID:5517854

Blomhoff, R; Berg, T; Norum, K R ^[1]

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1. Univ. of Oslo (Norway)

Newly absorbed chylomicron remnant retinyl ester is endocytosed by parenchymal liver cells, and retinol is subsequently transferred to perisinusoidal stellate cells in liver. In the present study, the authors have used several approaches to elucidate the mechanism for the paracrine transfer of retinol between liver parenchymal and stellate cells. In one series of experiments, chylomicrons labeled with ({sup 3}H)retinyl palmitate or with retinyl ({sup 3}H)palimtate were injected intravenously into rats. It was shown that the retinol as well as the palmitate moiety were initially taken up in parenchymal liver cells. However, only the retinol moiety was detected in stellate cells, indicating that the retinyl ester is hydrolyzed before retinol is transferred to stellate cells. It is well known that parenchymal liver cells secrete retinol bound to retinol-binding protein (RBP), and they have recently found that stellate cells do have RBP receptors. Here they report that antibodies against RBP completely block the transfer of retinol from parenchymal to stellate cells. These findings indicate that following uptake of chylomicron remnant retinyl ester in parenchymal cells, the retinyl ester is hydrolyzed, and retinol secreted from parenchymal cells on RBP is taken up by stellate cells by means of RBP receptors.

• OSTI ID: 5517854
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:10; ISSN PNASA; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANTIBODIES
BODY
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
GLANDS
HEXADECANOIC ACID
HYDROGEN COMPOUNDS
LIVER
MASS TRANSFER
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PHYSIOLOGY
PROTEINS
TRITIUM COMPOUNDS
VITAMIN A
VITAMINS