Hepatocytes and hepatic stellate cells play important roles in retinoid storage and metabolism. Hepatocytes process postprandial retinyl esters and are responsible for secretion of retinol bound to retinol-binding protein (RBP) to maintain plasma retinol levels. Stellate cells are the body's major cellular storage sites for retinoid. We have characterized and utilized an immortalized rat stella...

Retinol-binding protein (RBP) transports vitamin A in the plasma. It consists of eight anti-parallel beta-strands (A to H) that fold to form an orthogonal barrel. The loops connecting the strands A and B, C and D, and E and F form the entrance to the binding site in the barrel. The retinol molecule is found deep inside this barrel. Apart from its specific interaction with retinol, RBP is involv...

Retinol and its active derivative retinoic acid have an important role in development, reproduction, immunity, and cell proliferation/differentiation. Obesity and dyslipidemia are risk factors for cardiovascular disease that may affect hepatic homeostasis. It is unclear whether the expression of retinol-related proteins is affected and influences the retinol status in obesity and dyslipidemia. ...

Two cellular retinol-binding proteins (CRBP I and II) with distinct tissue distributions and retinoid-binding properties have been recognized thus far in mammals. Here, we report the identification of a human retinol-binding protein resembling type I (55.6% identity) and type II (49.6% identity) CRBPs, but with a unique H residue in the retinoid-binding site and a distinctively different tissue...

OBJECTIVE To examine select adipokines, including fatty acid-binding protein 4, retinol-binding protein 4, and high-molecular-weight (HMW) adiponectin in relation to cardiovascular disease (CVD) mortality among patients with type 2 diabetes mellitus. APPROACH AND RESULTS Plasma levels of fatty acid-binding protein 4, retinol-binding protein 4, and HMW adiponectin were measured in 950 men with...

The effect of chronic alcohol consumption on the concentration of 25-hydroxyvitamin D3, total retinol, and retinol-binding protein in serum was studied in chronic alcoholics (n = 12) and controls (n = 19). Ethanol intake during the last year was 178 +/- 116 and 3.7 +/- 4.5 g/day, respectively (p less than 0.002). Of the alcoholics, 58% had a concentration of 25-hydroxyvitamin D3 below lower lim...

We studied the effects of vitamin A deficiency and repletion on rat insulin release and islet cellular retinol binding protein (CRBP) and cellular retinoic acid binding protein (CRABP). Biphasic insulin release from vitamin A-deficient perifused islets was markedly impaired. Release remained impaired with retinoic acid (RA) repletion, 2 micrograms/g diet compared to release from islets of rats ...