Retinol In Blood Research Articles

Analysis of the correlation between semen parameters and the levels of retinol, tocopherol and carotenoids in human seminal plasma and blood

Investigate the levels of liposoluble vitamins in both human seminal plasma and blood and draw correlations to sperm quality in terms of concentration, motility and morphology. Additionally, MDA (Malonyldialdeide) and AOPP (Advanced Oxidation Protein Products) levels were analyzed as indicators to the degree of oxidation.

Serum Retinol Binding Protein 4 (RBP-4) is a Unique Surrogate Marker of END Stage Liver Disease With Complications. A Pilot Clinical Trial

Background: Retinol binding protein 4 (RBP-4), a 21 kilodalton plasma protein, is secreted from the liver and adipose tissue, and is known to transport retinol in the blood. RBP-4 levels have an inverse relationship with disease progression and decompensation. This study evaluates the role of RBP-4 on assessing the severity of decompensated liver disease Methods: 85 patients (n=85) (age=49.6±11.4, mean±SD) with moderate to -severe liver disease (mean MELD of 18) were recruited into three groups: Group AChronic liver disease with cirrhosis (n=30):20/30 HCV (67%) 8/30 HBV (27%) 2/30 Misc (6.6%) with mean MELD of 22; Group Bnon-cirrhotic (n=30) 13/20 HCV (43%), 4/20 HBV (13.3%), 5/30 Alcoholics (17%), and 5/30 misc (17%) with mean MELD of <10 Group Ccontrols (n=25) with MELD <10, Liver biopsy, insulin resistance (HOMA-score), MELD score, adiponectin, Leptin and serum RBP-4 (ELISA), APRI, Hyaluronic acid, and Hepascore for liver fibrosis were analyzed Results: There was a significant difference in RBP-4 across the cirrhotic, non-cirrhotic, and control groups (F(2, 82)=47.9, p<0.001; one-way ANOVA). Posthoc Bonferroni tests over controls (n=25, 4.21+/1.60; mean+/-SD). RBP4 is significantly decreased in Cirrhotics (p<0.001; n=30, 1.46+/0.51) over the non-Cirrhotics (p=0.015; n=30, 3.37+/0.97) and controls. Cirrhotics also had decreases in HOMA (1.09±0.09 vs. 1.51±0.60; p=0.001, Student's t-test),adiponectin (0.93±0.40 vs. 1.26±0.53; p=0.01), but with an increase in TNFalpha (11.23±3.81 vs. 3.72±3.37; p<0.001) compared to the non-cirrhotic patients. Leptin (8.20±3.23 vs. 10.93±9.44; p=0.14) and hepatic steatometry (BURNT score<4)-(0.73±0.83 vs. 1.10±1.21; p=0.19 showed no difference. RBP 4 has no relevant correlations with TNFalpha (r=-0.62, p<0.001), leptin (r=0.12, p=0.38) and hepatic steatometry (BURNT score<4)(r=0.12, p=0.41). RBP-4 correlated negatively with MELD score (r=-0.57, p=0.001) Conclusions: This pilot study proposed that RBP-4 has a role as a biomarker for endstage liver disease, with an independent, inverse relationship with severity of fibrosis, hepatic decompensation, MELD score, and complications of liver failure. There is a positive correlation with insulin resistance, metabolic syndrome, and Adipokines, but not with hepatic steatometry. A larger prospective clinical trial needs to be conducted to validate the unique role of RBP-4 in fibrosis and decompensated liver disease.

Identification of Glucose Transporter 4 Knockdown-dependent Transcriptional Activation Element on the Retinol Binding Protein 4 Gene Promoter and Requirement of the 20 S Proteasome Subunit for Transcriptional Activity

Retinol binding protein 4 (RBP4) is the transport protein that carries retinol in blood. RBP4 was described recently as a new adipokine that reduced insulin sensitivity. Mice lacking glucose transporter 4 (GLUT4) in adipocytes have enhanced Rbp4 gene expression; however, the molecular mechanism is unknown. We found a G4KA (GLUT4 knockdown-dependent transcriptional activation) element located approximately 1.3 kb upstream of the Rbp4 promoter. Mutations within the G4KA sequence significantly reduced expression of the Rbp4 promoter-reporter construct in G4KD-L1 (GLUT4 knockdown 3T3-L1) adipocyte cells. In a yeast one-hybrid screen of a G4KD-L1 cell cDNA library, using the G4KA element as bait, we identified subunits of the 20 S proteasome, PSMB1 and PSMA4, as binding partners. In chromatin immunoprecipitation assays, both subunits bound to the G4KA element; however, only PSMB1 was tightly bound in the GLUT4 knockdown model. PSMB1 RNA interference, but not PSMA4, significantly inhibited Rbp4 transcription. Nuclear transportation of PSMB1 was increased in G4KD-L1 cells. These results provide evidence for an exclusive proteasome subunit-related mechanism for transcriptional activation of RBP4 within a GLUT4 knockdown model.

Dantrolene may prevent organophosphate-induced oxidative stress and muscle injury

The effects of dantrolene against fenthion-induced oxidative stress and muscle injury were investigated in rats. Malondialdehyde (MDA), reduced glutathione (GSH) ascorbic acid, retinol and β-carotene levels in blood were measured. Histopathological alterations and apoptosis in diaphragm were examined. Fenthion increased the level of MDA and decreased the levels of GSH in blood. Dantrolene administration prevented the rise in MDA levels and increased the GSH levels. There was no significant difference between β-carotene levels of experimental groups. However, fenthion toxicity led to decrease in ascorbic acid and retinol levels, dantrolene administration significantly prevented this decrease. Dantrolene significantly decreased the inflammation, edema and muscle necrosis or apoptosis in diaphragm muscle. Results of present study showed that toxicity of organophosphate compound fenthion increases the lipid peroxidation and depresses endogenous antioxidative systems, and leads to muscle injury in organism. Again, dantrolene administration prevents lipid peroxidation, augments antioxidant activity, and decreases muscle injury and apoptosis.

Carotenoids, retinol and tocopherols in blood: Comparability between serum and plasma (Li-heparin) values

Objective: To assess the comparability of concentrations of retinol, α- and γ-tocopherols and individual carotenoids in serum and (Li-hep) plasma over a wide range of concentrations. Material and methods: One hundred sixty-six pairs of samples (serum and lithium-heparin plasma) were analyzed by a quality-controlled HPLC method. Means and 95% confidence intervals, differences, interchangeability and the degree of agreement (Bland–Altman plot) were calculated. Results: Distribution of all analytes in the two matrices are comparable and interchangeable with minor quantitative adjustments. Within the range of concentrations assessed, the degree of agreement was high, although some differences were observed for minor components with greater analytical imprecision. Conclusions: The results indicate an acceptable degree of agreement using either of the two matrices for the analytes assessed except possibly for minor blood components. For retinol and α-tocopherol, the comparability and interchangeability of results below the cut-off points for inadequacy need further confirmation.

Method for the Simultaneous Determination of Retinol and β-Carotene Concentrations in Human Tissues and Plasma

To understand differential tissue distribution of retinoids and carotenoids, as it might influence biological processes in humans, we developed and demonstrated a method for measuring them in selected human tissues. The method includes internal standards and a secondary reference standard to eliminate the need for external standard calibration and to minimize sample-handling errors. Tissues were digested (saponified) in ethanolic KOH. Retinol and β-carotene were extracted with organic solvent containing internal standards. Analytes were separated using isocratic liquid chromatography and quantified at 325 nm for retinol and 450 nm for β-carotene. Plasma was analyzed in a similar way but without saponification. Retinal-O-ethyloxime and β-apo-12′-carotenal-O-t-butyloxime served as internal standards. Plasma, breast, and fat from breast surgery patients and colon, liver, muscle, and fat from colon surgery patients were analyzed. Within-day relative standard deviations (RSDs) for plasma were <0.04 for β-carotene and <0.03 for retinol, between-day RSDs were <0.05 for β-carotene and <0.04 for retinol. Saponification ensured complete extraction of retinol and β-carotene and removal of triglycerides that “foul” chromatographic columns. It seems retinol and β-carotene concentrations in tissues and blood of cancer patients are the same or higher than those in corresponding tissues of patients without these cancers.

Hubungan Kandungan Karotenoid Dan Retinol Dalam Darah Dan Asi Pada Ibu Menyusui Di Daerah Penghasil Dan Bukan Penghasil Sayuran

Association of Carotenoids and Retinol Levels In Blood and Breastmilk of Breastfeeding Mothers In Vegetables Producing Area and Non-Vegetables Producing Area.Background: Vegetables are available in abundant amount in the less developed countries, including Indonesia, and are the source of carotenoids and other important nutrient, especially vitamin A. In rural areas, vegetables are becoming important source of vitamin A, especially for breastfeeding mothers.Objectives: To study carotenoids and retinol levels in blood and breastmilk of breastfeeding mothers in vegetables producing area and non-vegetables producing area, and its implication to the availability of vitamin A to breastfeeding mothers.Method: Samples were collected from 87 breastfeeding mothers with their breastfeeding age of 3-6 months, and they came from two areas, vegetables producing area and non-vegetables producing area. Blood and breastmilk were taken and analyzed for their carotenoids and retinol levels using HPLC.Results: The study found there were differences of carotenoids components and retinol in blood and breastmilk of breastfeeding mothers between vegetables producing area and non-vegetables producing area. The levels of lutein, lycopene, β-carotene and retinol in blood of breastfeeding mothers living in vegetables producing area were significantly different (pl0.01) from non vegetables producing area. However, for β-cryptoxanthin, and α-carotene were not significantly different (pg0.05). The levels of carotenoids and retinol in breastmilk showed differences. The levels of lutein, lycopene, α-carotene, β-cryptoxanthin and retinol in breastmilk of mothers in vegetables producing area were significantly different (pl0.01) from non-vegetables producing area. While β-carotene level was not significantly different (pg0.05). There were a correlation of lutein (r=0.4610, pl0.05), β-cryptoxanthin (r=0.3321, pl0.05), and β-carotene (r=0.4548, pl0.05) levels between in blood and breastmilk in vegetables producing area. While only level of lutein (r=0.6166, pl0.01) in blood correlated with breastmilk in non-vegetables producing area. There was no strong correlation (pg0.05) between vegetables consumption and carotenoids and retinol levels of blood and breastmilk, botj in vegetables producing area and non-vegetables producing area.Conclusion: The result of study showed carotenoids and retinol levels of blood and breastmilk in mothers from vegetables producing area were higher than that of non-vegetables producing area.Recommendation: To encourage breastfeeding mothers in order to consume more vegetables intensively through the existing program.

Oxidative stress, metabolism of ethanol and alcohol-related diseases.

Alcohol-induced oxidative stress is linked to the metabolism of ethanol. Three metabolic pathways of ethanol have been described in the human body so far. They involve the following enzymes: alcohol dehydrogenase, microsomal ethanol oxidation system (MEOS) and catalase. Each of these pathways could produce free radicals which affect the antioxidant system. Ethanol per se, hyperlactacidemia and elevated NADH increase xanthine oxidase activity, which results in the production of superoxide. Lipid peroxidation and superoxide production correlate with the amount of cytochrome P450 2E1. MEOS aggravates the oxidative stress directly as well as indirectly by impairing the defense systems. Hydroxyethyl radicals are probably involved in the alkylation of hepatic proteins. Nitric oxide (NO) is one of the key factors contributing to the vessel wall homeostasis, an important mediator of the vascular tone and neuronal transduction, and has cytotoxic effects. Stable metabolites--nitrites and nitrates--were increased in alcoholics (34.3 +/- 2.6 vs. 22.7 +/- 1.2 micromol/l, p < 0.001). High NO concentration could be discussed for its excitotoxicity and may be linked to cytotoxicity in neurons, glia and myelin. Formation of NO has been linked to an increased preference for and tolerance to alcohol in recent studies. Increased NO biosynthesis also via inducible NO synthase (NOS, chronic stimulation) may contribute to platelet and endothelial dysfunctions. Comparison of chronically ethanol-fed rats and controls demonstrates that exposure to ethanol causes a decrease in NADPH diaphorase activity (neuronal NOS) in neurons and fibers of the cerebellar cortex and superior colliculus (stratum griseum superficiale and intermedium) in rats. These changes in the highly organized structure contribute to the motor disturbances, which are associated with alcohol abuse. Antiphospholipid antibodies (APA) in alcoholic patients seem to reflect membrane lesions, impairment of immunological reactivity, liver disease progression, and they correlate significantly with the disease severity. The low-density lipoprotein (LDL) oxidation is supposed to be one of the most important pathogenic mechanisms of atherogenesis, and antibodies against oxidized LDL (oxLDL) are some kind of epiphenomenon of this process. We studied IgG oxLDL and four APA (anticardiolipin, antiphosphatidylserine, antiphosphatidylethanolamine and antiphosphatidylcholine antibodies). The IgG oxLDL (406.4 +/- 52.5 vs. 499.9 +/- 52.5 mU/ml) was not affected in alcoholic patients, but oxLDL was higher (71.6 +/- 4.1 vs. 44.2 +/- 2.7 micromol/l, p < 0.001). The prevalence of studied APA in alcoholics with mildly affected liver function was higher than in controls, but not significantly. On the contrary, changes of autoantibodies to IgG oxLDL revealed a wide range of IgG oxLDL titers in a healthy population. These parameters do not appear to be very promising for the evaluation of the risk of atherosclerosis. Free radicals increase the oxidative modification of LDL. This is one of the most important mechanisms, which increases cardiovascular risk in chronic alcoholic patients. Important enzymatic antioxidant systems - superoxide dismutase and glutathione peroxidase - are decreased in alcoholics. We did not find any changes of serum retinol and tocopherol concentrations in alcoholics, and blood and plasma selenium and copper levels were unchanged as well. Only the zinc concentration was decreased in plasma. It could be related to the impairment of the immune system in alcoholics. Measurement of these parameters in blood compartments does not seem to indicate a possible organ, e.g. liver deficiency.

Determination of Retinol and Retinoic Acid in Capillary Blood by High Performance Liquid Chromatography

A simplified method for quantitation of retinol in capillary blood by high-performance liquid chromatography (HPLC) is described. Serum (10-20 μl) obtained by centrifugation of capillary blood is extracted with a solvent mixture of isopropanol-dichloroethane, and the extract is directly injected into a HPLC system to quantitate retinol. The lower limit of quantitation is 0.25 ng retinol, thus permitting quantitation of serum or plasma level of 8 μg or more retinol/L. Although endogenous retinoic acid cannot be analyzed, retinoic acid, following an oral dose, can be extracted along with retinol in presence of acetic acid and quantitated. The lower limit of quantitation of retinoic acid is 0.5 ng, thus permitting quantitation of 50 ng or more of retinoic acid/ml serum or plasma. The small sample size required, their simple preparation, and rapid analysis make this method well suited for clinical studies. The method should be very useful for monitoring retinol level in blood of patients suspected of vitamin A deficiency or of retinol and retinoic acid levels in patients undergoing retinoic acid therapy for skin disorders or acute promyelocytic leukemia

Effect of postnatal steroid administration on serum vitamin A concentrations in newborn infants with respiratory compromise

Antenatal administration of glucocorticoids accelerates the fetal maturation of the lung, liver, and gastrointestinal tract. ~-3 w e previously demonstrated a significant elevation of.serum retinol, retinol-binding protein, and transthyretin concentrations in the cord blood of newborn infants whose mothers received betamethasone antenatally. 4 It was unclear from that study, however, whether this represented an effect primarily on the mother, the placenta, or the fetus. Mammel et al. 5 and others 6 demonstrated that postnatal steroid administration decreases alveolar-arterial oxygen gradients and improves lung mechanics in bronchopulmonary dysplasia, The mechanism of action remains unknown. Vitamin A has also been implicated in the prevention and treatment of bronchopulmonary dysplasia by promoting normal lung development and healing. 78 On the basis of these studies, we investigated the effect of postnatal dexamethasone administration on the vitamin A status of 13 infants who were treated with steroids because of significant respiratory compromise.

A re-examination of the stability of retinol in blood and serum, and effects of a standardized meal.

We examined the stability of retinol in blood and serum samples, kept in the dark, under different handling procedures. Samples not protected from contact with air oxygen were highly unstable, even when kept at ice temperature. Samples collected under anaerobic conditions, with Vacutainer Tubes, or treated with nitrogen after collection to displace the air from the tubes were stable during the usual interval between collection and freezing or analysis in biochemical surveys. Ingestion of a moderate amount of vitamin. A significantly increased serum retinol concentrations in normal volunteers, showing the importance that survey samples be preprandial.

Reference intervals for vitamins B1, B2, E, D, retinol, beta-carotene, and folate in blood: usefulness of dietary selection criteria.

Reference intervals for normal concentrations in blood of vitamins B1, B2, E, D, retinol, beta-carotene, and folic acid were determined from a selected sample of people attending a Health Examination Center or being examined in occupational health services in France. This reference sample consisted of 362 men and women, ages 18 to 44 years, selected according to the main variation factors known for the vitamins studied: consumption of tobacco and alcohol, ponderal index (relating height and weight), use of drugs and oral contraceptives, and past history of surgical or medical treatment. Reference intervals were determined for each sex. Vitamin B1 (erythrocyte transketolase activity), plasma retinol, and folic acid values in whole blood are significantly higher in men than in women (p less than 0.001), but vitamin B2 (activation of erythrocyte glutathione reductase) and plasma beta-carotene values are significantly higher in women (p less than 0.001 and less than 0.01 respectively). Dietary intake of vitamins produced no significant displacement of the reference values. For each vitamin we discuss the other major sources of variation factors and the usual values reported in the literature.

Proteins, vitamin A, carotene, folacin, ferritin and zinc in Navajo maternal and cord blood.

Blood samples were obtained from 28 Navajo women at delivery and cord blood samples were collected from their healthy, full-term infants. The concentrations of retinol, folacin, ferritin and zinc in the cord blood fell in the normal range even though some mothers had blood levels suggesting a deficiency. Levels of maternal and cord blood retinol-binding protein were positively correlated. Although marginal and deficient levels of folacin in maternal blood did not result in significantly lower cord blood levels, the strong association indicated a dependence of fetal level upon maternal supply. Birth weight and the developmental indices were not related to any of the maternal or fetal nutrient levels.