Zinc status of grazing sheep: seasonal changes in zinc concentrations in plasma, wool and pasture

1980 ◽  
Vol 20 (102) ◽  
pp. 20 ◽  
Author(s):  
DG Masters ◽  
M Somers
Keyword(s):  
Seasonal Variation ◽  
Seasonal Changes ◽  
Indirect Evidence ◽  
Zinc Content ◽  
Zinc Status ◽  
Plasma Zinc ◽  
South West ◽  
Zinc Concentrations ◽  
Grazing Sheep ◽  
Zinc Levels

Zinc status of grazing sheep was surveyed for three years on six properties in the south-west of Western Australia. The concentration of zinc in the plasma of rams and ewes varied both among sheep and among properties, and was up to 21% lower in autumn than in spring. The zinc status of ewes, but not rams, remained low in winter, as reflected by both plasma and wool levels. Pasture zinc levels were lowest in autumn and highest in winter, and regular recordings below 20 �g g-1 were made. The low zinc status of sheep in autumn was accompanied by low pasture zinc content and a low pasture availability. However, the data suggest that the decrease in maternal zinc levels during winter are due to reproductive stress. Plasma zinc levels regularly fell below the presently suggested optimum, and seasonal variation in both plasma and wool zinc levels indicates that in autumn and possibly winter there is an inadequate uptake of zinc. This is indirect evidence for a widespread marginal deficiency of zinc in grazing sheep.

Changes in plasma zinc content after exercise in men fed a low-zinc diet

1984 ◽  
Vol 247 (1) ◽  
pp. E88-E93 ◽  
Author(s):  
H. C. Lukaski ◽  
W. W. Bolonchuk ◽  
L. M. Klevay ◽  
D. B. Milne ◽  
H. H. Sandstead
Keyword(s):  
Copper Content ◽  
Maximal Exercise ◽  
Strong Predictor ◽  
Zinc Content ◽  
Plasma Zinc ◽  
Zinc Depletion ◽  
Plasma Copper ◽  
Zinc Concentrations ◽  
Zinc Repletion ◽  
Zinc Balance

For 30 days five healthy men aged 23-57 yr consumed a diet adequate in zinc (8.6 mg/day); they ate a low-zinc diet (3.6 mg/day) for the next 120 days and then received a zinc-supplemented (33.6 mg/day) diet for 30 days. Copper intake was constant at 1.8 mg/day. Aerobic capacity was determined periodically during each diet period. Relative zinc balance (% of control) declined during depletion (r = -0.28, P less than 0.009). Pre- and postexercise zinc concentrations decreased when dietary zinc was restricted (r = -0.61, P less than 0.0001 and r = -0.78, P less than 0.0001) and increased with supplementation (r = 0.61, P less than 0.008 and r = 0.76, P less than 0.0003, respectively). Both plasma zinc and hematocrit increased (P less than 0.01) after maximal exercise. To minimize the effect of hemoconcentration during exercise, the van Beaumont quotient (J. Appl. Physiol. 34: 102-106, 1973) was calculated using pre- and postexercise hematocrit and plasma zinc. The initial quotient of 1.8 +/- 1.8% (mean +/- SE) declined (P less than 0.05) to -7.4 +/- 2.3% during depletion. With zinc repletion, the quotient increased to 6.9 +/- 3.6%, which was greater (P less than 0.05) than the quotient in depletion but similar to the initial quotient. The quotient was a strong predictor (r = 0.71, P less than 0.0005) of the change in relative zinc balance during zinc depletion. In contrast, no changes were found in plasma copper content. These data suggest that zinc mobilization from tissues is impaired during zinc depletion, and they validate the use of the van Beaumont quotient as an index of change in body zinc stores.

Measurement of Hypozincaemia in Mice: A Sensitive Test for Detection of Pyrogens

1981 ◽  
Vol 61 (4) ◽  
pp. 445-449 ◽  
Author(s):  
Susan Boobis ◽  
Rose E. Hartley
Keyword(s):  
Escherichia Coli ◽  
Zinc Concentration ◽  
Shigella Dysenteriae ◽  
Metabolic Inhibitor ◽  
Repeated Treatment ◽  
Plasma Zinc ◽  
Sensitive Test ◽  
Zinc Concentrations ◽  
Zinc Levels ◽  
Dose Dependent

1. The effect of bacterial pyrogens on plasma zinc concentration in mice was studied as a method of bioassay for these substances. 2. A dose-related depression of plasma zinc concentrations was observed 4 h after intravenous injection of doses of 0.05-500 ng of purified endotoxins of Salmonella abortus equi, Shigella dysenteriae and Escherichia coli. Responses were dose-dependent and reproducible for each endotoxin in five strains of mice. 3. Tolerance to endotoxin could be induced in mice by injection of doses of 500 ng but was not seen with doses of <5 ng, even after repeated treatment. 4. Dinitrophenol, a metabolic inhibitor, and amphetamine, a metabolic enhancer, did not affect plasma zinc levels, indicating that changes in basal metabolic rate do not affect the outcome of this assay. The effects of pyrogenic materials other than endotoxin on plasma zinc levels were also tested and the results suggest that measurement of hypozincaemia in mice provides the basis for a simple, practical and inexpensive test for endotoxins and other pyrogens.

scholarly journals Effects of time since previous meal and time of day on plasma zinc concentrations in community‐based intervention trials: implications for assessing population zinc status

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Kenneth H Brown ◽  
Joanne E Arsenault ◽  
Sara E Wuehler ◽  
Daniel López Romaña ◽  
Mary E Penny ◽  
...  
Keyword(s):  
Time Of Day ◽  
Zinc Status ◽  
Plasma Zinc ◽  
Community Based ◽  
Zinc Concentrations ◽  
Intervention Trials

scholarly journals Zinc status affects p53, gadd45, and c-fos expression and caspase-3 activity in human bronchial epithelial cells

2001 ◽  
Vol 281 (3) ◽  
pp. C751-C757 ◽  
Author(s):  
Jessica C. Fanzo ◽  
Scott K. Reaves ◽  
Libin Cui ◽  
Lei Zhu ◽  
John Y. J. Wu ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Target Genes ◽  
P53 Protein ◽  
Zinc Status ◽  
Plasma Zinc ◽  
Gene Target ◽  
Bronchial Epithelial ◽  
Normal Human ◽  
Zinc Levels ◽  
Cellular Zinc

This study was designed to examine the influence of zinc depletion and supplementation on the expression of p53 gene, target genes of p53, and caspase-3 activity in normal human bronchial epithelial (NHBE) cells. A serum-free, low-zinc medium containing 0.4 μmol/l of zinc [zinc deficient (ZD)] was used to deplete cellular zinc over one passage. In addition, cells were cultured for one passage in media containing 4.0 μmol/l of zinc [zinc normal (ZN)], which represents normal culture concentrations (Clonetics); 16 μmol/l of zinc [zinc adequate (ZA)], which represents normal human plasma zinc levels; or 32 μmol/l of zinc [zinc supplemented (ZS)], which represents the high end of plasma zinc levels attainable by oral supplementation in humans. Compared with ZN cells, cellular zinc levels were 76% lower in ZD cells but 3.5-fold and 6-fold higher in ZA and ZS cells, respectively. Abundances of p53 mRNA and nuclear p53 protein were elevated in treatment groups compared with controls (ZN). For p53mRNA abundance, the highest increase (3-fold) was observed in ZD cells. In contrast, the highest increase (17-fold) in p53 nuclear protein levels was detected in ZS cells. Moreover, gadd45mRNA abundance was moderately elevated in ZD and ZA cells and was not altered in ZS cells compared with ZN cells. Furthermore, the only alteration in c-fos mRNA and caspase-3 activity was the twofold increase and the 25% reduction, respectively, detected in ZS compared with ZN cells. Thus p53, gadd45, and c-fos and caspase-3 activity appeared to be modulated by cellular zinc status in NHBE cells.

Oral contraceptives, norethindrone and mestranol: effects on tissue levels of minerals

1976 ◽  
Vol 231 (1) ◽  
pp. 98-103 ◽  
Author(s):  
KY Lei ◽  
AS Prasad ◽  
E Bowersox ◽  
D Oberleas
Keyword(s):  
Causative Factor ◽  
Atomic Absorption Spectrophotometry ◽  
Plasma Zinc ◽  
Sprague Dawley ◽  
Liver Iron ◽  
Zinc Intake ◽  
Sprague Dawley Rats ◽  
Plasma Copper ◽  
Zinc Concentrations ◽  
Zinc Levels

The study involved three levels of dietary zinc (deficient, marginal, and adequate) and four hormonal conditions; namely, no steriods, norethindrone, mestranol, and norethindrone plus mestranol. The steroids were incorporated into diets and fed to 11-wk-old female Sprague-Dawley rats. After 10 wk of treatment, various tissues were excised for mineral assays by atomic-absorption spectrophotometry. Both steroids, reduced weight gain. Mestranol depressed plasma zinc, tibia copper and magnesium, and liver iron, but elevated the zinc levels in liver and erythrocytes, plasma copper, liver magnesium and calcium, and iron content of tibia and heart. In general, the effect was most prominent with adequate zinc but diminished in magnitude with the reduction of zinc intake. In addition, norethindrone increased heart iron and tibia calcium. Mestranol appeared to be the main causative factor and may have induced a possible shift of minerals from one pool to another. As expected, zinc deficiency resulted in the reduction of zinc concentrations of plasma, tibia, kidney, and pancreas, and the elevation of copper, iron, magnesium, and calcium concentrations of various tissues.

Tissue zinc status and drug elimination in patients with chronic liver disease

1990 ◽  
Vol 78 (6) ◽  
pp. 547-549 ◽  
Author(s):  
Michael Barry ◽  
P. W. N. Keeling ◽  
John Feely
Keyword(s):  
Hepatic Cirrhosis ◽  
Serum Zinc ◽  
Zinc Content ◽  
Control Group ◽  
Zinc Status ◽  
Antipyrine Clearance ◽  
Zinc Depletion ◽  
Antipyrine Kinetics ◽  
Healthy Control ◽  
Zinc Concentrations

1. The zinc status and drug-metabolizing ability of 15 patients with histologically diagnosed hepatic cirrhosis were studied. Zinc status was assessed using both serum and leucocyte zinc concentrations, and drug-metabolizing ability was assessed by antipyrine kinetics. 2. Patients with cirrhosis were found to have lower serum and leucocyte zinc concentrations when compared with a healthy control group. 3. Leucocyte zinc content and antipyrine clearance were correlated. Those patients with the lowest leucocyte zinc content had the greatest impairment of drug metabolism. Antipyrine elimination and serum zinc concentrations were not correlated. 4. Leucocyte zinc concentrations and antipyrine clearance were not influenced by the severity of liver dysfunction, as assessed by using the Child Turcotte classification. 5. These results suggest that tissue zinc depletion in some patients with hepatic cirrhosis may explain in part the impaired capacity to metabolize drugs.

Dietary Intake and Thiamin, Iron, and Zinc Status in Elite Nordic Skiers during Different Training Periods

1992 ◽  
Vol 2 (4) ◽  
pp. 351-365 ◽  
Author(s):  
Mikael Fogelholm ◽  
Seppo Rehunen ◽  
Carl-Gustav Gref ◽  
Juha T. Laakso ◽  
Jari Lehto ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Seasonal Changes ◽  
Zinc Status ◽  
Food Record ◽  
Zinc Intake ◽  
Food Records ◽  
Iron And Zinc ◽  
Zinc Concentrations ◽  
Calcium Magnesium ◽  
Biochemical Indices

This study evaluated how different training periods affect dietary intake and biochemical indices of thiamin, iron, and zinc status in elite Nordic skiers. Subjects.were 17 skiers and 39 controls, ages 18-38 yrs. Dietary data were collected by 7-day food records at 3-month intervals. Coefficient of variation (CV) was used to indicate magnitude of seasonal changes. Energy intake for the year (28 food record days) was 3,802 kcallday (CV 19.1%) in male skiers, 2,754 kcallday (CV 3.7%) in male controls, 2,812 kcallday (CV 9.1%) in female skiers, and 2,013 kcallday (CV 5.9%) in female controls. CVs for thiamin, riboflavin, vitamin C, calcium, magnesium, iron, and zinc intake were 14.1-23.9% (male skiers), 2.9-15.0% (male controls), 4.8-24.5% (female skiers), and 4.3-1 1.5% (female controls). Seasonal changes in energy, carbohydrate, and micronutrient intakes reflected energy expenditure in male endurance athletes particularly. Erythrocyte transketolase activation coefficients and serum ferritin and zinc concentrations did not differ between skiers and controls. Seasonal variations in these biochemical indices of nutritional status were of the same magnitude in skiers and controls, despite large changes in skiers' physical activity.

Australian freashwater mussel Velesunio ambiguus (Philippi) as a biological monitor for zinc, iron and manganese

1983 ◽  
Vol 34 (6) ◽  
pp. 873 ◽  
Author(s):  
PJ Millington ◽  
KF Walker
Keyword(s):  
Heavy Metals ◽  
Body Weight ◽  
Zinc Content ◽  
Toxicity Tests ◽  
Confidence Limits ◽  
Environmental Fluctuations ◽  
Zinc Concentrations ◽  
Valve Opening ◽  
Zinc Levels ◽  
Iron And Manganese

The hyriid mussel V. ambiguus has been proposed as a biological monitor of zinc where there are wide environmental fluctuations. However, in the River Murray there is high variation in zinc content among individuals and between populations; part is systematic, associated with body weight and age, but a larger part remains statistically unexplained. Further, although V. ambiguus readily accumulates zinc, depuration is slow. At zinc concentrations of 20 mg I-1 and above, mussels avoid taking up zinc by significantly curtailing siphoning, movement and valve opening. Zinc levels above 20 mg l-1 are lethal, with most deaths occurring in the post-exposure periods immediately after 96-, 176- and 336-h toxicity tests. The estimated 336-h LC50 is 66 mg I-1, with 95% confidence limits 55 and 77 mg I-1. Exposure of caged mussels in the zinc-contaminated Molonglo River, N.S.W., suggests that V. ambiguus is not a suitable species to monitor variations in zinc loads between sites, and does not accurately reflect environmental fluctuations of zinc, iron or manganese, although it may have potential for materials other than heavy metals.

Investigation of the effect of supplementary zinc on growth rate of beef cattle on farms in N. Scotland

1980 ◽  
Vol 95 (1) ◽  
pp. 135-139 ◽  
Author(s):  
J. Price ◽  
W. R. Humphries
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Beef Cattle ◽  
Zinc Concentration ◽  
Zinc Content ◽  
Daily Weight Gain ◽  
Plasma Zinc ◽  
Zinc Concentrations ◽  
The Mean ◽  
And Control

SummaryTrials were conducted on 21 farms to examine the influence of supplementary zinc on growth rate of 978 beef cattle maintained on winter rations typical of N.E. Scotland.The concentration of zinc in the normal farm rations ranged from 13·3 to 32·1 mg/kg D.M. and half of the animals on trial on each farm received supplements providing an additional 60 mg Zn/kg D.M. Before supplementation, the farm mean plasma zinc concentrations varied from 0·73 to l·10mg Zn/l; these levels were not elevated by zinc supplementation.The differences in mean daily weight gain between zinc-supplemented and control cattle on individual farms during 100–140 days on trial ranged from –0·14 to +0·22 kg/day and were not related to plasma zinc concentration before supplementation or to the zinc content of the basal rations. The mean daily weight gain of heifers receiving supplementary zinc was significantly greater (P< 0·02) than that of the controls by 0·05 kg/day during the first 60–80 days only. Bulls and steers showed no response to supplementary zinc.

scholarly journals Zinc status in attention-deficit/hyperactivity disorder: a systematic review and meta-analysis of observational studies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mojtaba Ghoreishy ◽  
Sara Ebrahimi Mousavi ◽  
Farzaneh Asoudeh ◽  
Hamed Mohammadi
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Effect Size ◽  
Attention Deficit ◽  
Meta Analysis ◽  
Zinc Status ◽  
Plasma Zinc ◽  
Hyperactivity Disorder ◽  
Online Databases ◽  
Mean Differences ◽  
Zinc Levels

AbstractPrevious studies regarding the zinc status in attention-deficit/hyperactivity disorder (ADHD) yielded inconsistent results. Thus, the present meta-analysis was aimed to estimate the association between hair and serum/plasma zinc levels and ADHD. Online databases of Medline, EMBASE, and Scopus were searched up to October 2020 with no limitation in time and language. Weighted mean differences (WMDs) of hair and serum/plasma zinc levels were calculated using a random-effects model. Overall, 22 articles with 1280 subjects with ADHD and 1200 controls were included. The pooled effect size indicated that serum/plasma zinc levels in subjects with ADHD were not statistically different than their controls (WMD = − 1.26 µmol/L; 95% CI − 3.72, 1.20). Interestingly, the exclusion of one study from the analysis showed that people with ADHD significantly have lower circulating levels of zinc compared to their controls (WMD: − 2.49 µmol/L; 95% CI − 4.29, − 0.69). Also, the pooled effect size indicated that hair zinc levels in cases with ADHD were not statistically different than their controls (WMD = − 24.19 μg/g; 95% CI − 61.80, 13.42). Present meta-analysis raises the possibility that subjects with ADHD are prone to have declined levels of zinc levels. Based on current findings, screening the zinc levels in subjects with ADHD could be reasonable. Further well-designed studies are needed to clarify the role of zinc in the etiology of ADHD.

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