Two experiments evaluated the relationship of vitamin E (source and level) and vitamin A (level) on the apparent absorption and retention of both vitamins in weaned pigs. Both experiments used a combined total of 460 crossbred pigs ([Yorkshire x Landrace] x Duroc), housed in elevated 1.2- x 1.2-m crates containing five pigs per pen. Experiment 1 was a 2 x 2 x 2 factorial arrangement of treatmen...

A positive correlation has been established between increased oxidative stress and cardiovascular diseases in diabetes mellitus. We evaluated the effects of single or combined treatments with vitamin A (retinol acetate, 30 mg/kg/day, for 12-weeks) and insulin (8-10 IU/rat/day for the final 6-week) on vasomotor activity, oxidative stress and retinol metabolism in 12-week streptozotocin diabetic ...

Retinol plays a vital role in the immune response to infection, yet proteins that mediate retinol transport during infection have not been identified. Serum amyloid A (SAA) proteins are strongly induced in the liver by systemic infection and in the intestine by bacterial colonization, but their exact functions remain unclear. Here we show that mouse and human SAAs are retinol binding proteins. ...

The effects of moderate-intensity light (150 to 200 ft-cd) on retinal structure were compared between retinol-adequate and retinol-deficient rats after 1 to 6 days of light exposure during the 12 hr light phase of the cycle. Both damage to the outer segments and loss of photoreceptor cells were accelerated in retinol-adequate rats. Outer segments in retinas of retinol-adequate rats showed an ab...

BACKGROUND Retinoids are lipophilic isoprenoids composed of a cyclic group and a linear chain with a hydrophilic end group. These compounds include retinol, retinal, retinoic acid, retinyl esters, and various derivatives of these structures. Retinoids are used as cosmetic agents and effective pharmaceuticals for skin diseases. Retinal, an immediate precursor of retinoids, is derived by β-carote...

Cellular retinol-binding protein (type II) (CRBP(II)), a newly described retinol-binding protein, is present in the small intestinal absorptive cell at high levels. Retinol (vitamin A alcohol) presented as a complex with CRBP(II) was found here to be esterified by microsomal preparations from rat small intestinal mucosa. The esterification observed utilized an endogenous acyl donor(s) and produ...

Retinol, bound non-specifically to serum proteins in organ culture medium, caused the degradation of the extracellular matrix of chick limb-bone rudiments. The loss of polymeric material was demonstrated histologically and measured chemically. Retinol, at the same concentration, bound specifically to retinol-binding protein, produced no significant effect. The addition of prealbumin to this sys...

Retinol (vitamin A) is thought to exert its effects through the actions of its metabolite, all-trans-retinoic acid (ATRA), on gene transcription mediated by retinoic acid receptors (RAR) and retinoic acid response elements (RARE). However, retinoic acid resistance limits the chemotherapeutic potential of ATRA. We examined the ability of retinol to inhibit the growth of ATRA-sensitive (HCT-15) a...

Terminal differentiation of the keratinocytes (cornification) has been linked to a restricted supply of retinol. Retinol is distributed to target cells by the retinol-binding protein (RBP), which circulates in the plasma in complex with transthyretin (TTR). In this study we have addressed the question of retinol delivery to the epidermis via RBP. Retinol radiobinding assays, affinity chromatogr...

Aging comprises of two synergistic processes: intrinsic or chronologic aging, and extrinsic aging. Ultraviolet (UV) radiation is the main accelerator skin ageing, inducing production reactive oxygen species (ROS) pro-inflammatory mediators in cells. Retinol gold standard anti-aging treatments. As part a multi-decade ethnicity study, we studied human skin’s response either to UVA exposure an enh...