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...

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...

1. We have recently shown that the stellate cells, under normal conditions, contain a majority (more than 80%) of the total store of retinol in liver (Blomhoff et al. 1985). 2. In the present work we have studied the role of the various liver cells in rats of different ages, sex and vitamin A status. 3. In most of these groups of rats, storage of retinol in parenchymal cells was proportional to...

We recently demonstrated a rapid up-regulation of serum retinol-retinol binding protein-transthyretin concentration in rats with short-term acute renal failure. We examine the effect of retinoic acid and apo-retinol binding protein (apo-RBP) on the up-regulation of serum retinol in renal failure. Injection of retinoic acid (10 micrograms) into rats with acute renal failure or sham-operated rats...

Retinol acetate hydrolase is localized in rat liver microsomes whereas the retinol palmitate-hydrolyzing activity was found in the nuclear and in the mitochondrial lysosome-rich fractions. Acetone-dried powder from whole rat liver retained all of its retinol palmitate-hydrolyzing activity. Ammonium sulfate fractionation of the acetone-dried powder yielded a partially purified enzyme liberating ...

A rapid, selective and sensitive ultra-performance liquid chromatography method has been developed for the detection and quantification of tocopherols and retinol in human plasma. Alpha-tocopherol, gamma-tocopherol and retinol are assayed using fluorescence detection. Excitation/emission wavelengths are 295/330 nm and 325/470 nm for the analysis of both tocopherols and retinol, respectively. Re...