scholarly journals Pregnancy and Lactation Alter Vitamin A Metabolism and Kinetics in Rats under Vitamin A-Adequate Dietary Conditions

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2853
Author(s):  
Yaqi Li ◽  
Ayasa Tajima ◽  
Floyd Mattie ◽  
Michael Green ◽  
A. Catharine Ross
Keyword(s):  
Vitamin A ◽  
Primary Source ◽  
Compartmental Analysis ◽  
Female Rats ◽  
Whole Body ◽  
Physiological Status ◽  
Female Rat ◽  
Limited Information ◽  
Pregnancy And Lactation ◽  
The Impact

Background: Vitamin A (VA) plays critical roles in prenatal and postnatal development; however, limited information is available regarding maternal VA metabolism during pregnancy and lactation. Objectives: We investigated the impact of pregnancy and lactation on VA metabolism and kinetics in rats, hypothesizing that changes in physiological status would naturally perturb whole-body VA kinetics. Methods: Eight-week old female rats (n = 10) fed an AIN-93G diet received an oral tracer dose of 3H-labeled retinol to initiate the kinetic study. On d 21 after dosing, six female rats were mated. Serial blood samples were collected from each female rat at selected times after dose administration until d 14 of lactation. Model-based compartmental analysis was applied to the plasma tracer data to develop VA kinetic models. Results: Our compartmental model revealed that pregnancy resulted in a gradual increase in hepatic VA mobilization, presumably to support different stages of fetal development. Additionally, the model indicates that during lactation, VA derived from dietary intake was the primary source of VA delivered to the mammary gland for milk VA secretion. Conclusion: During pregnancy and lactation in rats with an adequate VA intake and previous VA storage, the internal redistribution of VA and increased uptake from diet supported the maintenance of VA homeostasis.

scholarly journals Pregnancy and Lactation Alter Vitamin A Metabolism and Kinetics in Rats under Vitamin A-Adequate Dietary Conditions

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 120-120
Author(s):  
Yaqi Li ◽  
Ayasa Tajima ◽  
Floyd Mattie ◽  
Erin Dexheimer ◽  
Elizabeth Soucy ◽  
...  
Keyword(s):  
Vitamin A ◽  
Female Rats ◽  
Male Rats ◽  
Whole Body ◽  
Physiological Status ◽  
Female Rat ◽  
Plasma Fraction ◽  
Pregnancy And Lactation ◽  
The Impact ◽  
Mated Female

Abstract Objectives We investigated the impact of pregnancy and lactation on vitamin A (VA) metabolism and kinetics in rats, hypothesizing that this changed physiological status would perturb whole-body VA kinetics. Such information may be informative for future dietary recommendations. Methods Ten female rats (7 wk of age) and 6 male rats (9 wk of age) were fed an AIN-93 G diet upon arrival. After 1 week of acclimation, female rats received an oral dose of 3H-labeled retinol as the tracer to initiate the kinetic study. On d 21 after dosing (when 3H-retinol was expected to reach a log-linear terminal slope), 6 female rats were mated and checked daily for a vaginal plug to determine the date of pregnancy. On the day of delivery, litter size was adjusted to 10 pups/dam. Serial blood samples were collected from each female rat at 27–28 time points after dose administration until dams and pups were euthanized on d 14 of lactation. Hematocrit was measured, plasma tracer level was determined, and plasma fraction of dose vs. time was plotted. Model-based compartmental analysis will be applied to the plasma tracer data to develop VA kinetic models. Results All mated female rats became pregnant (pregnant group, PG, n = 6). Non-mated female rats were studied as non-pregnant controls (CN, n = 4). No difference was observed in hematocrit between PG and CN rats, suggesting no significant change in plasma volume expansion. Before breeding, plasma tracer response profiles were similar to CN rats. However, a consistent decline in plasma tracer levels was observed in PG rats during the middle of pregnancy, followed by a rise in late pregnancy, whereas such a change did not occur in CN rats. Moreover, during lactation, PG rats exhibited a steeper terminal slope compared to CN rats, indicating a more rapid utilization of VA in these lactating rats. Conclusions Pregnancy and lactation resulted in altered VA metabolism and kinetics in rats. Further analysis using mathematical modeling will explore the changes in kinetic parameters that underlie the perturbations we have observed in VA kinetics. Funding Sources National Institutes of Health.

scholarly journals Dietary Iron Repletion Stimulates Hepatic Mobilization of Vitamin A in Previously Iron-Deficient Rats as Determined by Model-Based Compartmental Analysis

2020 ◽  
Vol 150 (7) ◽  
pp. 1982-1988 ◽  
Author(s):  
Yaqi Li ◽  
Cheng-Hsin Wei ◽  
Michael H Green ◽  
A Catharine Ross
Keyword(s):  
Iron Deficiency ◽  
Vitamin A ◽  
Time Course ◽  
Compartmental Analysis ◽  
Whole Body ◽  
Control Group ◽  
Sprague Dawley ◽  
Model Based ◽  
Iron Deficient ◽  
The Impact

ABSTRACT Background Iron deficiency can result in hyporetinolemia and hepatic vitamin A (VA) sequestration. Objectives We used model-based compartmental analysis to determine the impact of iron repletion on VA metabolism and kinetics in iron-deficient rats. Methods At weaning, Sprague-Dawley rats were assigned to either a VA-marginal diet (0.35 mg retinol equivalent/kg) with adequate iron (35 ppm, control group [CN]) or reduced iron (3 ppm, iron-deficient group [ID–]), with an equivalent average body weight for each group. After 5 wk, n = 4 rats from each group were euthanized for baseline measurements of VA and iron indices, and the remaining rats (n = 6 CN, n = 10 ID–) received an intravenous injection of 3H-labeled retinol in an emulsion as tracer to initiate the kinetic study. On day 21 after dosing, half of the ID– rats were switched to the CN diet to initiate iron repletion, referred to as the iron-repletion group (ID+). From the time of dosing, 34 serial blood samples were collected from each rat over a 92-d time course. Plasma tracer and tissue tracee data were fitted to 6- and 4-compartment models, respectively, to analyze the kinetic behavior of VA in all groups. Results Our mathematical model indicated that ID– rats exhibited a nearly 6-fold decrease in liver VA secretion and >4-fold reduction in whole-body VA utilization, compared with CN rats, whereas these perturbed kinetic behaviors were notably corrected in ID+ rats, close to those from the CN group. Conclusions Iron repletion can remove the inhibitory effect that iron deficiency exerts on hepatic mobilization of VA and restore retinol kinetic parameters to values similar to that of never-deficient CN rats. Together with improvements in iron and VA indices, our results suggest that restoration of an iron-adequate diet is sufficient to improve VA kinetics after a previous state of iron deficiency.

scholarly journals The “Super-Child” Approach Is Applied To Estimate Retinol Kinetics and Vitamin A Total Body Stores in Mexican Preschoolers

2020 ◽  
Vol 150 (6) ◽  
pp. 1644-1651 ◽  
Author(s):  
Veronica Lopez-Teros ◽  
Jennifer L Ford ◽  
Michael H Green ◽  
Brianda Monreal-Barraza ◽  
Lilian García-Miranda ◽  
...  
Keyword(s):  
Vitamin A ◽  
Corn Oil ◽  
Compartmental Analysis ◽  
Whole Body ◽  
Retinyl Acetate ◽  
Data Set ◽  
Mexican Children ◽  
Model Predictions ◽  
Total Body ◽  
Composite Data

ABSTRACT Background Retinol isotope dilution (RID) and model-based compartmental analysis are recognized techniques for assessing vitamin A (VA) status. Recent studies have shown that RID predictions of VA total body stores (TBS) can be improved by using modeling and that VA kinetics and TBS in children can be effectively studied by applying population modeling (“super-child” approach) to a composite data set. Objectives The objectives were to model whole-body retinol kinetics and predict VA TBS in a group of Mexican preschoolers using the super-child approach and to use model predictions of RID coefficients to estimate TBS by RID in individuals. Methods Twenty-four healthy Mexican children (aged 3–6 y) received an oral dose (2.96 μmol) of [13C10]retinyl acetate in corn oil. Blood samples were collected from 8 h to 21 d after dosing, with each child sampled at 4 d and at 1 other time. Composite data for plasma labeled retinol compared with time were analyzed using a 6-component model to obtain group retinol kinetic parameters and pool sizes. Model-predicted TBS was compared with mean RID predictions at 4 d; RID estimates at 4 d were compared with those calculated at 7–21 d. Results Model-predicted TBS was 1097 μmol, equivalent to ∼2.4 y-worth of VA; using model-derived coefficients, group mean RID-predicted TBS was 1096 μmol (IQR: 836–1492 μmol). TBS at 4 d compared with a later time was similar (P = 0.33). The model predicted that retinol spent 1.5 h in plasma during each transit and recycled to plasma 13 times before utilization. Conclusions The super-child modeling approach provides information on whole-body VA kinetics and can be used with RID to estimate TBS at any time between 4 and 21 d postdose. The high TBS predicted for these children suggests positive VA balance, likely due to large-dose VA supplements, and warrants further investigation.

scholarly journals The mode of action of anabolic agents: the effect of testosterone on muscle protein metabolism in the female rat

1984 ◽  
Vol 52 (3) ◽  
pp. 515-521 ◽  
Author(s):  
J. A. Martinez ◽  
P. J. Buttery ◽  
J. T. Pearson
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Mode Of Action ◽  
Muscle Protein ◽  
Female Rats ◽  
Daily Weight Gain ◽  
Whole Body ◽  
Female Rat ◽  
Trenbolone Acetate ◽  
Muscle Protein Metabolism

1. Testosterone (1 mg/kg body-weight per d) given subcutaneously to female rats increased their growth rate and food conversion efficiency but not their food intake compared with that of the placebo-oil controls. A higher dose of testosterone (10 mg/kg body-weight per d) failed to increase the daily weight gain.2. The increased growth rate of the testosterone-treated rats appeared to occur in the whole body and not specifically in muscle. There were no significant changes in body composition.3. The fractional synthetic rate of gastrocnemius muscle protein was higher in the hormone-treated rats than in controls. This contrasts with previous results for the anabolic agent trenbolone acetate and reflects differences in the mode of action of these two different steroids, both with androgenic properties.

scholarly journals Methodology for assessing the power of the primary source of the system of autonomous electrical supply with account of the predicted load graphics

2019 ◽  
Vol 64 (2) ◽  
pp. 205-214
Author(s):  
D. V. Karkotski ◽  
A. N. Malashin ◽  
S. A. Chumakov ◽  
Y. G. Koval
Keyword(s):  
Supply Voltage ◽  
Electric Energy ◽  
Operation Time ◽  
Primary Source ◽  
Electrical Energy ◽  
Quality Parameters ◽  
Limited Information ◽  
Autonomous Operation ◽  
Current Consumption ◽  
The Impact

When developing new or upgrading existing energy-intensive mobile objects (MO), the main way to ensure the quality parameters of the supply voltage is no worse than in the state grid, overestimation of the primary source (PS) power is 1.5–2 times relative to the maximum power of all electrical energy consumers (EEC) software.The consequence of the existing approach to determine the power of PS are: overestimation of the mass and dimensions of the autonomous power supply system (APSS) by 30–70 %, which significantly reduces speed characteristics, cross-country performance and battery autonomy of MO, as well as worsen the economics of the APSS; the workload of the PS APSS is not more than 35–55 % of the nominal capacity, which leads to a reduction in their service lives.Thus, it is impossible to take into account the peculiarities of the actual current consumption of individual EEC and the impact of their joint operation on specific PS APSS, which leads to additional financial costs and an increase in development time, as well as to the risk of failure during the testing of both the APSS and the equipment connected to it.The proposed approach for estimating the PS power of electric energy in APSS MO allows determining the full power of the EEC in terms of limited information about the EEC taking into account the nature of the load graph, as well as the magnitude and form of current consumption. As a result of analytical calculations according to the above methodology, the PS power can be reduced by 13–45 %, depending on the nature of the load, while maintaining the quality indicators of the supply voltage within acceptable limits.The considered methods for determining the power of the PS APSS will make it possible to determine the limitations for solving the problem of structural-parametric synthesis of the APSS and the algorithm for determining the power of the PS when developing a new or upgrading the existing APSS MO. This will reduce the weight and size parameters of the APSS, thereby increasing the speed characteristics, maneuverability and software permeability of MO, as well as the autonomous operation time and efficiency of the APSS operation.

scholarly journals The Effect of High-Fat Diet-Induced Obesity on the Expression of Nutrient Chemosensors in the Mouse Stomach and the Gastric Ghrelin Cell

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2493
Author(s):  
Maria Nunez-Salces ◽  
Hui Li ◽  
Stewart Christie ◽  
Amanda J. Page
Keyword(s):  
High Fat Diet ◽  
Primary Source ◽  
Nutrient Sensing ◽  
Mrna Levels ◽  
Limited Information ◽  
High Fat ◽  
Diet Induced Obesity ◽  
Standard Laboratory Diet ◽  
Ghrelin Secretion ◽  
The Impact

The stomach is the primary source of the orexigenic and adiposity-promoting hormone, ghrelin. There is emerging evidence on the nutrient-mediated modulation of gastric ghrelin secretion. However, limited information is available on gastric nutrient-sensing mechanisms in high-fat diet (HFD)-induced obesity. This study investigated the impact of HFD-induced obesity on the expression of nutrient chemosensors in mouse stomach, particularly ghrelin cells. Male C57BL/6 mice were fed either a standard laboratory diet (SLD) or HFD for 12 weeks. The expression of ghrelin, enzymes involved in ghrelin production (PC1/3, GOAT) and nutrient chemosensors (CD36, FFAR2&4, GPR93, CaSR, mGluR4 and T1R3) was determined by quantitative RT-PCR in the mouse corpus and antrum. Immunohistochemistry assessed the protein expression of CaSR and ghrelin in the corpus and antrum. Antral mRNA levels of CaSR and PC1/3 were increased in HFD compared to SLD mice, while mRNA levels of all other nutrient chemosensors examined remained unchanged. CaSR immunolabelling was observed in the gastric antrum only. Nearly 80% of antral ghrelin cells expressed CaSR, with a similar cell density and co-expression in SLD and HFD mice. In conclusion, HFD-induced obesity increased CaSR mRNA expression in mouse antrum. However, the high antral co-expression of CaSR and ghrelin was unaltered in HFD compared to SLD mice.

scholarly journals Better Predictions of Vitamin A Total Body Stores by the Retinol Isotope Dilution Method Are Possible with Deeper Understanding of the Mathematics and by Applying Compartmental Modeling

2019 ◽  
Vol 150 (5) ◽  
pp. 989-993 ◽  
Author(s):  
Michael H Green ◽  
Joanne Balmer Green ◽  
Jennifer Lynn Ford
Keyword(s):  
Vitamin A ◽  
Isotope Dilution ◽  
Theoretical Data ◽  
Compartmental Analysis ◽  
Whole Body ◽  
Optimal Time ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Model Based ◽  
Total Body

ABSTRACT Retinol isotope dilution (RID) is a well-accepted technique for assessing vitamin A status [i.e., total body stores (TBS)]. Here, in an effort to increase understanding of the method, we briefly review RID equations and discuss their included variables and their coefficients (i.e., assumptions that account for the efficiency of absorption of an orally administered tracer dose of vitamin A, mixing of the dose with endogenous vitamin A, and loss due to utilization). Then, we focus on contributions of another technique, model-based compartmental analysis and especially the “super-person” approach, that advance the RID method. Specifically, we explain how adding this modeling component, which involves taking 1 additional blood sample from each subject, provides population-specific estimates for the RID coefficients that can be used in the equation instead of values derived from the literature; using model-derived RID coefficients results in improved confidence in predictions of TBS for both a group and its individuals. We note that work is still needed to identify the optimal time for applying RID in different groups and to quantify vitamin A absorption efficiency. Finally, we mention other contributions of modeling, including the use of theoretical data to verify the accuracy of RID predictions and the additional knowledge that model-based compartmental analysis provides about whole-body vitamin A kinetics.

scholarly journals Pendidikan Anak Perspektif Kosmologi Islam (Kontekstualisasi Pemikiran Sachiko Murata)

2021 ◽  
Vol 15 (1) ◽  
pp. 19
Author(s):  
Fifin Sofia
Keyword(s):  
Forest Fires ◽  
Primary Source ◽  
Whole Body ◽  
Literature Study ◽  
Pollution Damage ◽  
Child Education ◽  
Human Need ◽  
Data Collection Technique ◽  
The Impact ◽  
The Universe

In essence, education is a basic human need, because humans are born endowed with various potentials that must be developed as provisions for living life as servants and representatives of Allah on earth. But in fact today, instead of being God's representative, humans create various chaos, both in their relationships with fellow humans—violence, brawl, bullying—and their relationship with the universe—garbage, air pollution, damage to marine ecosystems, water pollution, forest fires and so on. And the bad news is, Indonesia is included in the 5 countries with the most population in the world, so the habits of the Indonesian greatly influence world conditions. It seems that the various bad conditions that occur are the result of human actions who do not have good morals, this shows that the ongoing education system has not been able to lead humans to have the awareness that everything in the universe is related to one another, especially connection with God—or better known as Cosmology, or if it is compared to one body, when one limb is injured then the whole body feels the impact. This study aims to: 1) Know how the Islamic Cosmology Perspective of Sachiko Murata; 2) Knowing the concept of Islamic Cosmological Perspective Child Education in the contextualization of Sachiko Murata's thoughts. The research method used is descriptive qualitative, which has the primary source from Sachiko Murata's book The Tao of Islam, while the data collection technique uses literature study, and the data collected is analyzed using processing, categorization and interpretation. The results of this study are (1) God is viewed in two perspectives (duality), tanzih (incommensurability) and tasybih (likeness). To know God, Murata uses the tasybih approach. Islamic cosmology aims to emphasize tauhid (the oneness of Allah), which is depicted in the form of a triangle, encompassing God, nature and man in every corner, so that there is unity and interrelation between all realities; (2) Child education in the perspective of Islamic cosmology according to Sachiko Murata, building divine awareness that God is not only about Himself who is far from the reach of creatures, but we can see God scattered throughout the horizon and soul.

scholarly journals Perturbed Whole-body Vitamin a Kinetics Induced by Iron Deficiency Is Corrected by Dietary Iron Repletion in Rats (OR05-03-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Yaqi Li ◽  
Cheng-Hsin Wei ◽  
Xia Xiao ◽  
Michael Green ◽  
A Catharine Ross
Keyword(s):  
Iron Deficiency ◽  
Vitamin A ◽  
Kinetic Study ◽  
Whole Body ◽  
Control Group ◽  
Deficient Diet ◽  
Hematological Indices ◽  
Iron Deficient ◽  
Plasma Retinol ◽  
The Impact

Abstract Objectives We investigated the impact of iron repletion on vitamin A (VA) metabolism and kinetics in iron-deficient rats, hypothesizing that iron repletion can remove the inhibitory effect of iron deficiency on hepatic mobilization of VA and improve the hyporetinolemia of iron deficiency. Methods At weaning, rats were divided into two groups and fed either a VA-marginal diet (control group, CN) with normal levels of iron (37 ppm) or the same diet with reduced iron (5 ppm, iron deficient group, ID-). After 5 weeks, n = 4 rats from each group were euthanized for baseline measurements, and the remaining rats (n = 6 CN, n = 10 ID-) received an i.v. dose of 3H-labeled retinol in an emulsion as tracer to initiate the kinetic study. On day 21 after dosing, half of the ID- rats were switched to the CN diet, thus creating an iron repletion group (ID+). Serial blood samples were collected from each rat at 34 preselected time points after dosing. On day 92, all rats were euthanized. Iron and VA status were determined, and model-based compartmental analysis was applied to the plasma tracer data to develop VA kinetic models for rats from all groups. Results Rats fed the iron-deficient diet developed iron deficiency, and exhibited reduced plasma retinol (0.67 vs. 1.19 µmol/L), with higher liver VA (265 vs. 187 nmol) at the start of the kinetic study, suggesting impaired hepatic VA mobilization. At the study conclusion, ID+ rats had recovered from iron deficiency, as indicated by hematological indices including hemoglobin, hematocrit, and serum iron. While liver VA storage was more than doubled in ID- rats (456 nmol) vs. CN rats (190 nmol), hyporetinolemia was maintained in ID- rats. In contrast, VA in the liver of ID+ rats was mobilized, reflected by the reduced liver VA mass (276 nmol) and increased hepatic output of VA into plasma based on predictions of the compartmental model, and plasma retinol in ID + rats returned to normal. Conclusions Iron repletion restored plasma retinol concentrations and increased liver vitamin A mobilization in iron deficient rats. Funding Sources National Institutes of Health.

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