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...

The retinyl palmitate content of the postnuclear membrane fraction from 10 Morris hepatomas, their host rat livers, one acetylaminofluorene-induced rat liver hepatoma, and the host liver and of regenerating rat liver was measured by reverse-phase high-pressure liquid chromatography of the chloroform:methanol extracts. Membranes from the hepatoma tissue contained less than detectable levels of r...

To test the hypothesis that regulation of palmitate metabolism, through carnitine palmitoyl transferase-1 (CPT-1) or through alterations of glycolysis, was involved in the pathway of palmitate-mediated cell death, cardiomyocytes were cultured from 7-day-old chick embryos. Palmitate-induced cell death, assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, was enhan...

Food fortification is a cost-effective and sustainable strategy to prevent or correct micronutrient deficiencies. A double-blind cluster (bari) randomised controlled trial was conducted in a rural community in Bangladesh to evaluate the impact of consumption of chapatti made of micronutrient-fortified wheat flour for 6 months by school-aged children on their vitamin A, haemoglobin and iron stat...

Previous prospective studies have raised the possibility that the antioxidantproperties of carotenoids and vitamin E (alpha-tocopherol) and the role of vitamin A (retinol) in cellular differentiation may be associated with a reduced risk of subsequent breast cancer. To investigate the association between serum and plasma concentrations of retinol, retinyl palmitate, alpha-carotene, beta-caroten...

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...

Measurement of 13C-labeled fatty acid oxidation is hindered by the need for acetate correction, measurement of the rate of CO2 production in a controlled environment, and frequent collection of breath samples. The use of deuterium-labeled fatty acids may overcome these limitations. Herein, d31-palmitate was validated against [1-13C]palmitate during exercise. Thirteen subjects with body mass ind...