scholarly journals A stable isotope study of zinc kinetics in Irish setters with gluten-sensitive enteropathy

1995 ◽  
Vol 74 (1) ◽  
pp. 69-76 ◽  
Author(s):  
N. M. Lowe ◽  
E. J. Hall ◽  
R. S. Anderson ◽  
R. M. Batt ◽  
M. J. Jackson
Keyword(s):  
No Reduction ◽  
Zn Deficiency ◽  
Short Term ◽  
Zn Concentration ◽  
Gluten Sensitive Enteropathy ◽  
Isotope Study ◽  
Stable Isotope Study ◽  
And Control ◽  
Kinetics Of ◽  
Fractional Turnover

The short-term kinetics of Zn turnover were studied in Irish setters with gluten-sensitive enteropathy and control dogs following intravenous injection of 0·25 mg 96·5% enriched 70ZnCl2. The 70Zn enrichment of serum was found closely to obey two-compartment kinetics and the derived two-compartment decay equation was used to calculate the size and turnover of the two initial rapidly exchanging pools of body Zn. In normal Irish setters isotopic Zn initially equilibrates with a pool (a) of size 1·27 (SD 0·46) μmol/kg and then with a second pool (b) of size 6·83 (SD 1·72) μmol/kg. The fractional turnover of pool (b) was approximately one eighth that of pool (a). Enteropathic dogs showed no reduction in the size of either rapidly exchangeable Zn pool, reduction in serum Zn concentration or abnormality in Zn balance and hence these results do not support the possibility of an underlying Zn deficiency in this disorder.

scholarly journals A comparison of the short-term kinetics of zinc metabolism in women during fasting and following a breakfast meal

1998 ◽  
Vol 80 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Nicola M. Lowe ◽  
Leslie R. Woodhouse ◽  
Janet C. King
Keyword(s):  
Energy Content ◽  
Compartment Model ◽  
Zinc Metabolism ◽  
Short Term ◽  
Compartment System ◽  
Breakfast Meal ◽  
Physiological Importance ◽  
Two Compartment Model ◽  
Zn Concentration ◽  
Kinetics Of

The physiological importance and mechanism of the postprandial fall in plasma Zn concentration is not well understood. In order to gain further information on this apparent redistribution of plasma Zn, a stable isotope, 70Zn, was used to study the effect of a breakfast meal on plasma Zn kinetics. Nine women participated in two trials, a fasting trial and a breakfast-meal trial; five of the women participated in a third trial in which the energy content of the breakfast meal was doubled. At each trial, 0.1mg of 70Zn was infused intravenously, and the plasma disappearance of the isotope was analysed using a two-compartment model of Zn kinetics. Plasma Zn concentration fell significantly following the two trials in which the subjects were given meals, reaching low points that were 13 and 19 %, respectively, below concentrations at comparable times during the fasting trial. Kinetic analysis revealed that after the doubled breakfast meal there was a significant fall (P < 0.007) in the size of the most rapidly turning over Zn pool (pool (a)) from 2.90 (se 0.13)mg in the fasting state to 2.47 (se 0.14) mg postprandially. The fractional turnover rate of pool (a) to other extravascular Zn pools, i.e. outside the two-compartment system, was also significantly elevated after the doubled breakfast meal (P < 0.05). These results suggest that the decline in plasma Zn concentration following a meal is due to a redistribution of Zn from the plasma to other more slowly turning over extravascular pools that may be involved in the assimilation and metabolism of fuels following food intake.

Studies of human zinc kinetics using the stable isotope 70Zn

1993 ◽  
Vol 84 (1) ◽  
pp. 113-117 ◽  
Author(s):  
N. M. Lowe ◽  
A. Green ◽  
J. M. Rhodes ◽  
M. Lombard ◽  
R. Jalan ◽  
...  
Keyword(s):  
Liver Disease ◽  
Alcoholic Liver Disease ◽  
Turnover Rate ◽  
Kinetic Studies ◽  
Normal Subjects ◽  
Short Term ◽  
Control Subjects ◽  
Two Component ◽  
Kinetics Of ◽  
Fractional Turnover

1. The short-term (120 min) kinetics of Zn turnover has been studied in control subjects and patients with alcoholic liver disease after intravenous injection of 0.5 mg of 96.5% enriched 70ZnCl2. 2. The 70Zn enrichment of plasma was found closely to obey two-compartment kinetics and the derived two-component decay equation has been used to calculate the size and turnover of the initial two rapidly exchanging pools of body Zn. 3. In normal subjects isotopic Zn appears initially to equilibrate with the whole of the plasma Zn which comprises the first metabolic compartment, pool a. This has a size of 0.72 ± 0.1 μmol/kg. 70Zn equilibration then occurs with a second compartment, pool b, consistent with a rapidly exchanging liver Zn pool of size 3.60 ± 0.93 μmol/kg. The fractional turnover rate of pool b was found to be fivefold slower than that of pool a. 4. In the alcoholic group an expansion of pool a was observed (1.63 ± 0.39 μmol/kg), but the size of the second pool was not significantly different from that of control subjects (5.55 ± 1.0 μmol/kg), although its fractional turnover was significantly increased (Kab: control subjects, 0.018 ± 0.002 min−1, alcoholic patients, 0.031 ± 0.006 min−1). 5. These data therefore demonstrate that kinetic studies using stable isotopes of Zn can provide novel information on exchangeable Zn pools in man, but provide no support for the possibility of an underlying Zn depletion in patients with alcoholic liver disease.

Short-term enteral glutamine does not enhance protein accretion in burned children: a stable isotope study

Surgery ◽  
2004 ◽  
Vol 135 (6) ◽  
pp. 671-678 ◽  
Author(s):  
Robert L Sheridan ◽  
Kathrina Prelack ◽  
Yong-Ming Yu ◽  
Martha Lydon ◽  
Lisa Petras ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Short Term ◽  
Isotope Study ◽  
Stable Isotope Study

scholarly journals Measurement of zinc flux through plasma in normal and endotoxin-stressed pigs and the effects of Zn supplementation during stress

1981 ◽  
Vol 46 (1) ◽  
pp. 119-130 ◽  
Author(s):  
J. K. Chesters ◽  
Marie Will
Keyword(s):  
Plasma Volume ◽  
Physiological Response ◽  
Turnover Rates ◽  
Zn Concentration ◽  
Zn Content ◽  
Metabolic Requirement ◽  
And Control ◽  
Fractional Turnover

1. The rates of transport of zinc through plasma have been investigated in normal and endotoxin-stressed pigs.2.65Zn added to porcine plasma in vitro rapidly equilibrated with the Zn originally present.3.65Zn bound to albumin and injected intravascularly into pigs rapidly equilibrated with two kinetically distinguishable pools. The first of these pools was mainly associated with the plasma but was significantly larger than the plasma volume and substantially so in Zn-deficient pigs. The second pool appeared to represent a summation of the rapidly-exchangeable Zn within the extravascular tissues.4. In non-stressed animals, the flux of Zn from the plasma of Zn-deficient pigs was only half that in Zn-supplemented animals.5. Administration of endotoxin reduced the plasma Zn concentration of Zn-supplemented pigs but not of Zn-deficient animals. The fractional turnover rates of Zn were not altered in either of the two pools following endotoxin.6. At 10 h after giving endotoxin neither the Zn content of the two pools nor the flux of Zn through them differed significantly between Zn-deficient and control pigs.7. Intravascular infusion of Zn at a rate which essentially prevented the usual depression in plasma Zn concentration following endotoxin failed to alleviate the effects of endotoxin on Zn-supplemented pigs.8. The reduction in plasma Zn concentration following endotoxin stress appears to be a normal physiological response which is not indicative of an increased metabolic requirement for Zn.

scholarly journals The effect of zinc deficiency on alkaline phosphatase (EC 3.1.3.1) and its isoenzymes

1980 ◽  
Vol 43 (3) ◽  
pp. 561-569 ◽  
Author(s):  
F. A. Adeniyi ◽  
F. W. Heaton
Keyword(s):  
Alkaline Phosphatase ◽  
Small Intestine ◽  
Zinc Deficiency ◽  
Inhibitory Effect ◽  
Zn Deficiency ◽  
Electrophoretic Mobilities ◽  
Zn Concentration ◽  
Individual Bands ◽  
And Control ◽  
Total Alkaline

1. Zinc deficiency in young rats reduced both the total alkaline phosphatase (EC 3.1.3.1) activity and Zn concentration in serum, kidney, small intestine and femur.2. Addition of 0.01 mM-exogenous Zn had no greater activating effect with extracts of kidney, small intestine and femur from Zn-deficient than control rats, indicating that the main effect of the deficiency was on the amount of enzyme present rather than the efficiency of its operation. Exogenous Zn increased the activity of enzyme in serum of Zn-deficient rats, but it was still lower than in the serum of control animals.3. Electrophoresis on polyacrylamide gel separated the alkaline phosphatase activity from all tissues into two bands. The bands had similar electrophoretic mobilities and appeared to be qualitatively identical in corresponding tissues from Zn-deficient and control rats.4. Zn deficiency eliminated the first band found in serum from control rats and it had selective effects on the activity of individual bands in other tissues. The major inhibitory effect was on the first bands of enzyme activity in kidney and femur, but in small intestine only the second band was affected. In liver the activity of the first band was increased and that of the second band decreased by similar amounts.

Short Term Enteral Glutamine Does Not Enhance Protein Accretion in Burn Patients: A Stable Isotope Study

2001 ◽  
Vol 22 ◽  
pp. S139 ◽  
Author(s):  
R. L. Sheridan ◽  
K. Prelack ◽  
Y. Yu ◽  
M. K. Lydon ◽  
L. M. Petras ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Burn Patients ◽  
Short Term ◽  
Isotope Study ◽  
Stable Isotope Study

scholarly journals Effect of fasting and feeding on apolipoprotein A-I kinetics in preβ1-HDL, α-HDL, and triglyceride-rich lipoproteins

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Maud Chétiveaux ◽  
Mikaël Croyal ◽  
Khadija Ouguerram ◽  
Fanta Fall ◽  
Laurent Flet ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Healthy Male ◽  
Apolipoprotein A ◽  
Triglyceride Rich Lipoprotein ◽  
Isotope Study ◽  
Stable Isotope Study ◽  
Kinetics Of ◽  
Male Subjects

Abstract The aim of this study was to compare the kinetics of apolipoprotein (apo)A-I during fed and fasted states in humans, and to determine to what extent the intestine contributes to apoA-I production. A stable isotope study was conducted to determine the kinetics of apoA-I in preβ1 high-density lipoprotein (HDL) and α-HDL. Six healthy male subjects received a constant intravenous infusion of 2H3-leucine for 14 h. Subjects in the fed group also received small hourly meals. Blood samples were collected hourly during tracer infusion and then daily for 4 days. Tracer enrichments were measured by mass spectrometry and then fitted to a compartmental model using asymptotic plateau of very-low-density lipoprotein (VLDL) apoB100 and triglyceride-rich lipoprotein (TRL) apoB48 as estimates of hepatic and intestinal precursor pools, respectively. The clearance rate of preβ1-HDL-apoA-I was lower in fed individuals compared with fasted subjects (p < 0.05). No other differences in apoA-I production or clearance rates were observed between the groups. No significant correlation was observed between plasma apoC-III concentrations and apoA-I kinetic data. In contrast, HDL-apoC-III was inversely correlated with the conversion of α-HDL to preβ1-HDL. Total apoA-I synthesis was not significantly increased in fed subjects. Hepatic production was not significantly different between the fed group (17.17 ± 2.75 mg/kg/day) and the fasted group (18.67 ± 1.69 mg/kg/day). Increase in intestinal apoA-I secretion in fed subjects was 2.20 ± 0.61 mg/kg/day. The HDL-apoA-I kinetics were similar in the fasted and fed groups, with 13% of the total apoA-I originating from the intestine with feeding.

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

Zinc application enhances grain zinc density in genetically-zinc-biofortified wheat grown on a low-zinc calcareous soil

2018 ◽  
pp. 107-110 ◽  
Keyword(s):  
Developing Countries ◽  
Grain Yield ◽  
Calcareous Soil ◽  
Zn Deficiency ◽  
Target Level ◽  
Zn Concentration ◽  
Grain Zinc ◽  
Zn Availability ◽  
Zinc Application ◽  
Grain Zn Concentration

Human zinc (Zn) deficiency is a worldwide problem, especially in developing countries due to the prevalence of cereals in the diet. Among different alleviation strategies, genetic Zn biofortification is considered a sustainable approach. However, it may depend on Zn availability from soils. We grew Zincol-16 (genetically-Zn-biofortified wheat) and Faisalabad-08 (widely grown standard wheat) in pots with (8 mg kg−1) or without Zn application. The cultivars were grown in a low-Zn calcareous soil. The grain yield of both cultivars was significantly (P≤0.05) increased with that without Zn application. As compared to Faisalabad-08, Zincol-16 had 23 and 41% more grain Zn concentration respectively at control and applied rate of Zn. Faisalabad-08 accumulated about 18% more grain Zn concentration with Zn than Zincol-16 without Zn application. A near target level of grain Zn concentration (36 mg kg−1) was achieved in Zincol-16 only with Zn fertilisation. Over all, the findings clearly signify the importance of agronomic Zn biofortification of genetically Zn-biofortified wheat grown on a low-Zn calcareous soil.

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