Cones function in constant light and are responsible for mediating daytime human vision. Like rods, cones use the photosensitive molecule 11-cis-retinal to detect light, and in constant illumination, a continuous supply of 11-cis-retinal is needed. A retina visual cycle is thought to provide a privileged supply of 11-cis-retinal to cones by using 11-cis-retinol generated in Müller cells. In the...

The retinal pigment epithelium (RPE) is a monolayer of cuboidal cells that lies in close association with the rod and cone photoreceptors. This epithelium has diverse features, three of which are discussed in some detail in this review, namely the daily phagocytosis of rod and cone outer segment fragments that are shed from their distal ends; the uptake, processing, transport and release of vit...

Background: Whereas conventional white cassava roots are devoid of provitamin A, biofortified yellow varieties are naturally rich in b-carotene, the primary provitamin A carotenoid. Objective: We assessed the effect of consuming yellow cassava on serum retinol concentration in Kenyan schoolchildren with marginal vitamin A status. Design:We randomly allocated 342 children aged 5–13 y to receive ...

The mammalian small intestine contains two related cellular retinol-binding proteins, CRBP and CRBP II, which are thought to have distinct functions. The human intestinal cell line, Caco-2, was used as a model system for testing the hypothesis that intracellular levels of these proteins directly modulate the absorption and subsequent metabolism of retinol in enterocytes. Immunoblot and Northern...

Vitamin A (retinol) deficiency is a recognised complication of cystic fibrosis and is presumed to be a consequence of an impairment in the digestion and absorption of dietary fats. The dietary intake of fat and retinol was assessed from a seven day weighed food intake in 11 subjects with cystic fibrosis and 12 matched controls. Faecal excretion of retinol and fat were measured from three day st...

Diabetes is a metabolic disorder characterized by chronic hyperglycemia. Advanced diabetes is associated with severe complications and impaired nutritional status. Here, we assessed the expression of retinol-associated proteins, including β-carotene 15,15'-monooxygenase (BCMO), lecithin:retinol acyltransferase (LRAT), aldehyde dehydrogenase (ALDH), and cytochrome P450 26A1 (CYP26A1), and measur...

Studies were conducted to explore the role of retinol in the control of the rate of synthesis of plasma retinolbinding 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...

Vitamin A deficiencies in pregnancy may impair the health of the mother and the growth, development, and later health of her offspring. However, the understanding of the variability of micronutrient status markers during pregnancy is limited. We measured serum retinol and β-carotene and the acute phase proteins C-reactive protein (CRP) and α(1)-antichymotrypsin (ACT) in 738 pregnant women in a ...

Biodegradable salicylic acid-based poly(anhydride-ester)s (SAPAE) have proven to be effective in many biomedical applications including controlling inflammation, promoting bone growth, and preventing biofilm formation due the release of acid upon hydrolysis polymer anhydride ester bonds. Microspheres SAPAE are one fabrication option available for encapsulation controlled hydrophobic small molec...

Vitamin A (retinol) is required to maintain immunity and epithelial turnover and is a key micronutrient needed for combating infection. Vitamin A actions on the immune system are diverse and cannot be accounted for by a single effect or mechanism. The actions of retinol in maintaining gut integrity in humans and immunoglobulin levels in mice was investigated. For 30 children, performance on the...