Search results for "Retinol binding protein"
showing 4 items of 14 documents
Xanthine oxidase catalyzes the oxidation of retinol.
2007
In mammals, xanthine oxidase (E.C. 1.17.3.2) catalyzes the hydroxylation of a wide variety of heterocyclic substrates such as purines, pyrimidines, and pterins, in addition to aldehydes [1] as all-trans-retinaldehyde [2-5]. Here, we show that buttermilk xanthine oxidase was capable to oxidizing all-trans-retinol (t-ROL) to all-trans-retinaldehyde (t-RAL) that was successively oxidized to all-trans-retinoic acid (t-RA). A rise in the enzyme activity, when t-ROL-CRBP complex was assayed, with respect to the free t-ROL, was observed. Furthermore, treatment of the enzyme with Na2S and glutathione resulted in a significant increment in catalytic activity toward t-ROL and t-RAL, due to the recons…
Estrogen Inhibits Retinoic Acid Biosynthesis In Tumor Breast Epithelial Cell Lines
2008
PS-078 Clinical Relevance Of Gamma-glutamyl Transpeptidase In Childhood Obesity
2014
Background and aims Metabolic risk leads to severe comorbidities in obesity. We evaluate the relationship between the values of gamma-glutamyl trans peptidase (GGT), a marker of hepatic involvement, and cardio metabolic risk factors in obese children. Methods A prospective cross-sectional study of 147 children (aged 7 to 16 years) was carried out. Ninety-five children were obese with a body mass index standard deviation score (SDS-BMI) >2 and 52 children were normal weight. Patients with endocrine disease or syndromic obesity were excluded. We have analysed clinical parameters of adiposity (fat mass by bioelectrical impedance, waist and hip circumference), blood pressure, and classical bioc…
Low levels of both xanthine dehydrogenase and of cellular retinol binding protein are responsible for retinoic acid deficiency in malignant human mam…
2009
The seeming impairment of retinoid metabolism in human breast tumor cells has been attributed to the lower expression of cellular retinol binding proteins (CRBPs), of alcohol/retinol dehydrogenases, or aldehyde/retinaldehyde dehydrogenases. In a previous study we indicated that xanthine dehydrogenase (XDH) is able to oxidize actively both all-trans-retinol (t-ROL) bound to the CRBP (holo-CRBP) and all-trans-retinaldehyde (t-RAL) to all-trans-retinoic acid (t-RA) in human mammary epithelial cells (HMEC). Since both XDH and CRBP are required for the biosynthesis of t-RA, we have inspected their bioavailability in both estrogen-responsive and nonresponsive human mammary epithelial cancer cells…