Premium
Retinoids: in vitro interaction with retinol‐binding protein and influence on plasma retinol
Author(s) -
Berni Rodolfo,
Clerici Monica,
Malpeli Giorgio,
Cleris Loredana,
Formelli Franca
Publication year - 1993
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.7.12.8375617
Subject(s) - retinol , retinol binding protein , in vitro , retinol binding protein 4 , chemistry , plasma protein binding , microbiology and biotechnology , biochemistry , endocrinology , biology , vitamin , insulin resistance , insulin , adipokine
Studies have been conducted to investigate the structure‐function relationships of retinoids in their in vitro interaction with plasma retinol‐binding protein (RBP) and in their influence on plasma retinol concentration. Two classes of retinoids, one bearing modifications in the area of the retinol hydroxyl end group (fenretinide, N‐(ethyl) retinamide, all‐trans, and 13‐ cis retinoic acid) and the other one also bearing modifications in the area of the cyclohexene ring (etretinate, acitretin, and arotinoid Ro 13‐7410), were investigated. Whereas substantial modifications of the retinol hydroxyl group do not prevent the binding to RBP, an intact trimethylcyclohexenyl group seems to be crucial for binding. Both classes of retinoids, administered orally at equimolar doses, reduce plasma retinol concentration in rats but with different kinetics. A marked lowering of plasma retinol occurs early (within 5 h) after administration of retinoids that interact with RBP in vitro, whereas it occurs at later times (24 h) after retinoids that do not interact with RBP. The concentrations of both classes of retinoids found in plasma do not account for the temporal difference in this effect. The early reduction of plasma retinol might be the consequence of in vivo specific binding of retinoids to RBP, as suggested by the in vitro results. The late reduction observed for retinoids lacking in vitro affinity for RBP is due to other mechanisms or to metabolism to retinoids binding to RBP.—Berni, R., Clerici, M., Malpeli, G., Cleris, L., Formelli, F. Retinoids: in vitro interaction with retinol‐binding protein and influence on plasma retinol. FASEB J. 7: 1179‐1184; 1993.