Studies were conducted to explore the role of retinol in the control of the rate of synthesis of plasma retinol-binding protein (RBP) in the liver of the rat. Previous studies have shown that nutritional retinol status strongly influences RBP secretion from the liver cell. Both the in vivo relative rate of RBP synthesis and the in vitro translatable level of RBP-specific mRNA were examined in n...

vitamin a is the generic name given to a group of fat-soluble compounds including retinol (the alcohol form), retinyl esters, retinaldehyde and retinol acid. deficiency, first recognized in 1912, can damage the epithelial cells lining the respiratory tract. it can also affect immunocompetence, the reproductive function, growth and vision. the dose of vitamin a for neonates is 5,000 iu given int...

Subjects with chronic liver disease are susceptible to hypovitaminosis A due to several factors. Therefore, identifying patients with vitamin deficiency and a requirement for vitamin supplementation is important. Most studies assessing vitamin A in the context of hepatic disorders are conducted using cirrhotic patients. A cross-sectional study was conducted in 43 non-cirrhotic patients with chr...

Retinol-binding protein 4 (RBP4) is a plasma protein involved in retinol transportation, and recent evidence in rodents suggests that RBP4 is also a metabolic regulator that modifies insulin sensitivity. To assess how RBP4 levels are regulated in ruminants, we determined the RBP4 concentrations in bovine plasma and milk using Western blot analysis. Plasma RBP4 levels in non-pregnant non-lactati...

OBJECTIVE This study assessed the vitamin A nutritional status of preterm infants determined by the vitamin A relative dose-response test (RDR) compared with serum levels of vitamin A, retinol-binding protein (RBP), transthyretin (TTR), and retinol relations with carrier proteins. METHODS Serum levels of retinol, RBP, and TTR and retinol/RBP, retinol/TTR, and RBP/TTR molar ratios were determi...

Vitamin A and its derivatives, particularly retinol, slow both chronological photo-induced aging processes. Retinol reduces the appearance of wrinkles decrease skin firmness elasticity by protecting against collagen elastin fiber changes. In addition to retinol’s rejuvenating benefits through direct transcriptional activation, recent studies also suggest an epigenetic regulation micro-RNAs (miR...

Retinol dehydrogenase solubilized by Lubrol 12A9 from bovine retinal rod outer segments forms mixed micelles of Stokes radius 8.5 nm. The kinetic properties of the solubilized retinol dehydrogenase were examined and retinaldehyde reduction and retinol oxidation were seen to proceed at pH 8.3 by a sequential Ordered Bi Bi mechanism. This conclusion was supported by bisubstrate initial velocity s...

Retinol is transported in plasma bound to a specific transport protein, retinol-binding protein. We prepared 125I-tyramine cellobiose-labeled rat retinol-binding protein and studied its tissue uptake 1, 5, and 24 h after intravenous injection into rats. The liver was the organ containing most radioactivity at all time points studied. After 5 and 24 h, 30 and 22% of the injected dose were recove...

BACKGROUND Vitamin A deficiency adversely affects child morbidity and survival. This deficiency is estimated by measurement of plasma retinol concentrations, but because plasma retinol is reduced by clinical and subclinical infection, this proxy measure can lead to overestimation. Infection and trauma are accompanied by rises in concentrations of acute-phase proteins in plasma. We aimed to esti...

The objectives of the present study were to identify predictors of serum retinol concentration as well as to assess the prevalence of low serum retinol concentration, in both the whole population after correcting for the effect of serum C-reactive protein (CRP) (using multiple categories), and the healthy subgroup. A cross-sectional study of 579 apparently healthy children, aged 3-7 years from ...