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PubMed1993

Zinc supplementation restores plasma concentrations of zinc and thymulin in patients with Crohn's disease.

The aim of this work was to evaluate whether oral supplementation with zinc sulphate (ZnSO4) could restore thymic endocrine function in patients with Crohn's disease who showed decreased plasma concentrations of zinc and active thymulin, a zinc-dependent thymic hormone. Twenty-seven patients in clinical remission were randomly assigned to receive, for 3 months, one of the following treatments: 60 mg/day ZnSO4; 200 mg/day ZnSO4 or placebo. Plasma thymulin activity and zinc concentrations significantly increased only in patients treated with 200 mg/day ZnSO4. Lymphocyte subpopulations, within the range of normality before zinc supplementation, were unaffected by any of the administered treatments. In conclusion, low plasma concentrations of zinc and thymulin in Crohn's disease patients were restored by the administration of high doses of zinc.

Adult↗

PubMed1980

Zinc and zinc ligands in human seminal plasma. I. Methodological aspects and normal findings.

The occurrence of zinc ligands in human seminal plasma has been studied with gel filtration techniques. When an eluant of 0.05 M Tris with 0.15 M NaCl, pH 7.4, a mean of 11.6% of zinc was bound to ligands with a molecular weights greater than 80 000 (HMW), 26.9% to ligands with molecular weights between 3000 and 80 000 (IMW), and 61.5% to ligands with molecular weights less than 3000 (LMW), respectively (N = 21). Under standardized conditions the results were highly reproducible. There was a significant shift of zinc from HMW to LMW ligands if pH was less than 7 or higher than 8, or if phosphate ions were present. There was a temperature dependent shift of zinc from IMW towards LMW ligands indicating an enzymatic degradation of the IMW ligands. HMW was not changed with time if the semen samples were kept at room temperature for up 24 h. Despite a prostatic origin of zinc in human seminal plasma there was a co-variation to HMW, i.e. the higher the fructose concentration the more zinc was recovered from the HMW-ligands. If HMW originates from the seminal vesicles this indicate a post-ejaculatory re-distribution of zinc between different ligands.

Chromatography, Gel↗

PubMed1982

Tissue zinc levels as an index of body zinc status.

Dietary depletion of zinc was found to result in a 30% decrease in the total body zinc content of experimental rats when compared with control animals. In the depleted animals there was no decrease in the zinc content of hair, skin, heart or three different skeletal muscles although the levels in plasma, liver, bone, and testes were significantly reduced. The analysis of tissues from three patients suffering from disturbance of zinc metabolism suggest that man reacts to zinc deficiency in a similar way. These findings indicate that for a simple screening test of zinc status, analysis of the plasma zinc concentration remains the single most useful measurement.

Animals↗

PubMed2005

Chronic zinc toxicity in an infant who received zinc therapy for atopic dermatitis.

UNLABELLED: In Japan and many other industrialized countries, zinc is readily available as a nutritional supplement, for cosmetic purposes and for the treatment of atopic dermatitis. The potential risks associated with its use are not, however, fully recognized. As a reciprocal relationship exists between copper and zinc, excessive zinc can produce hypocupraemia, which can cause anaemia and neutropenia. We report on a male infant who presented with anaemia and neutropenia and showed signs of developmental delay after dietary restriction for food allergy and eating difficulties and zinc therapy administered for the treatment of atopic dermatitis at a dose nine times the daily dietary allowance for his age group. After 1 mo of zinc withdrawal, copper and ceruloplasmin concentrations had increased, and the blood cell count had improved, activity was increasing but verbal development remained limited. As development improved after withdrawal of zinc, we cannot rule out a relation between developmental delay and hyperzincaemia and/or hypocupraemia. CONCLUSION: Caution must be exercised in administering zinc to children during their neurological development.

Chronic Disease↗

PubMed1992

Anti-ulcer activity of a slow-release zinc complex, zinc monoglycerolate (Glyzinc).

A slow-release zinc complex, zinc monoglycerolate (ZMG) was examined for its potential gastroprotective activity in various gastric ulcer models. These models comprised (a) oral or parenteral non-steroidal anti-inflammatory drugs (NSAIDs) given to rats whose gastrointestinal mucosa was pre-sensitized by prior development of arthritis, oleyl alcohol-induced inflammation and cold exposure, (b) oral ethanol (12.5-100%) with and without added 4% HCl, (c) intraperitoneal reserpine (5 mg kg-1) in arthritic and normal rats and in normal mice, (d) oral NSAIDs given to mice in which acid and pepsin production was stimulated by co-administration of intraperitoneal bethanechol chloride (5 mg kg-1) to enhance ulcer development, and (e) NSAIDs given to carrageenan-inflamed rats to determine effects of ZMG on paw inflammation. In these models, ZMG given orally was effective in preventing development of gastric lesions, except with propionic acid NSAIDs; the effective doses being apparently dependent on the severity of the mucosal injury. In many of the models ZMG was superior to zinc sulphate and other zinc salts or metal ion complexes investigated but was slightly more effective or equipotent compared with zinc acexamate. ZMG did not impair the anti-oedemic effects of NSAIDs. ZMG is thus an effective agent in preventing ulcer development in a wide range of model systems and may be more effective than zinc salts because of the controlled slow-release of zinc from the complex.

Animals↗

PubMed1983

Influence of zinc status on postprandial plasma zinc changes in pigs.

In growing castrated pigs changes in the postprandial plasma zinc values were found to be inversely related to the zinc status of the animals. In pigs prefed with a moderate zinc diet (25 ppm) postprandial plasma zinc values increased, whereas in pigs prefed with a high zinc diet (150 ppm) values decreased after intake of a meal containing 150 ppm of zinc. It is considered that the presence of metallothioneine in the liver, which depends upon the zinc status, is responsible for this effect.

Animals↗

PubMed1979

Intravenous zinc sulfate therapy in zinc-depleted patients.

Zinc sulfate was administered intravenously in 3 patients with severe conditional zinc deficiency. The dosage ranged from 10 to 20 mg ionic zinc daily, and the duration of the treatment did not exceed 2 weeks. The rise in serum zinc and urinary zinc per 24 h, as well as in serum alkaline phosphatase, occurred at a faster rate than observed in a patient who was given 135 mg zinc daily by mouth. No subjective or biochemical side effects of the intravenous zinc therapy was observed.

Alkaline Phosphatase↗

PubMed1997

Autometallographic silver enhancement of zinc sulfide crystals created in cryostat sections from human brain biopsies: a new technique that makes it feasible to demonstrate zinc ions in tissue sections from biopsies and early autopsy material.

We present a new technique that allows zinc ions in synaptic and secretory vesicles of biopsy and early autopsy material (< 2 hr post mortem) to be transformed to nanometer-sized zinc sulfide crystal lattices for subsequent autometallographic (AMG) development. Human brain biopsies, or other tissue samples containing zinc-enriched (ZEN) cells, are frozen in liquid nitrogen or by CO2 gas immediately after removal. The tissue blocks are cut in a cryostat and the sections placed on glass slides. The slides are transferred to an H2S exposure chamber placed in a -15 C freezer. After 1-24 hr of gas exposure the sections are removed from the chamber, fixed while thawing, and dehydrated. The sections are then exposed to an AMG developer. AMG causes silver enhancement of zinc sulfide crystal lattices created in the tissues through the H2S exposure, making them visible. It is imperative that the tissues are frozen instantaneously after removal, because loosely bound or free zinc ions start leaving their vesicular compartment soon after death. The AMG technique can, despite inadequate fixation and damage to the tissue caused by freezing, also be used to trace zinc ions at ultrastructural levels, and it is demonstrated that zinc ions in the human neocortex are located in synaptic vesicles. In the few human biopsies analyzed thus far, the light microscopic pattern created by the silver-enhanced ZEN terminals resembles that seen in the neocortex of rat brain. The technique has been applied to cryostat sections from neocortex biopsies of five individuals undergoing brain surgery. Biopsies from three patients resulted in satisfactory AMG-stained sections. Rat brains removed and frozen immediately after decapitation constituted the material on which the present technique was developed. Such material results in an almost uniform high quality of staining, and we found that unexposed sections can be stored for at least 5 months at -80 C without ensuing significant loss of AMG staining intensity.

Animals↗

PubMed1996

Effects of thyroid hormone on erythrocyte carbonic anhydrase-I and zinc concentrations in vivo and in vitro: clinical usefulness of carbonic anhydrase-I and zinc concentrations in erythrocytes.

Red blood cell (RBC) carbonic anhydrase-I isozyme (CAI) and zinc concentrations were measured in patients with various thyroid diseases. Both concentrations were decreased in patients with hyperthyroid Graves' disease, and the RBC CAI concentration significantly (r = 0.95) correlated with the RBC zinc concentration. After treatment, the normalization of RBC CAI and zinc lagged 2 months behind normalization of plasma T4 and T3 levels. Furthermore, the highest correlation coefficients were observed between RBC CAI and zinc levels and plasma thyroid hormone levels measured 8 weeks earlier. These results indicate that both RBC CAI and zinc levels reflect the integrated plasma thyroid hormone levels over the previous few months. Transient thyrotoxicosis due to destructive (subacute or painless) thyroiditis did not cause significant changes in the RBC CAI and zinc concentrations. Therefore, the measurement of RBC CAI and zinc concentrations may be useful in differentiating patients with Graves' disease from those with transient thyrotoxicosis. T3 at a physiological free concentration significantly decreased CAI concentration in erythroleukemic YN-1 cells and burst forming unit-erythroid-derived cells obtained by culturing peripheral blood mononuclear cells. These cells may be useful in vitro models for investigations of thyroid hormone action in human erythroid cells.

Animals↗

PubMedDate not supplied

The effects of zinc on the olfactory neuroepithelium and olfactory bulbs of the Sprague-Dawley rat after oral administration of zinc-gluconate trihydrate.

BACKGROUND: The most frequent causes of upper respiratory infections are human rhinoviruses. The nasopharyngeal area, which includes the respiratory epithelium, mucosa, and the olfactory neuroepithelium (ONe), is a first-line of defense against airborne viruses and allergens, some of which manage to penetrate the nasal mucosa and invade the tissues of the nasal respiratory epithelium. Biochemical evidence from several studies suggests that zinc is an effective cold treatment and that over-the-counter (OTC) zinc-gluconate compounds may provide the high pharmacologic doses of zinc needed to act as an effective means of treating and reducing the duration and severity of symptoms of the common cold. METHODS: A series of male Sprague-Dawley rats were fed an oral preparation of zinc-gluconate trihydrate or received the equivalent through drinking water to investigate the potential cytotoxic and/or neurotoxic insult to the olfactory receptor cells and other tissue in the ONe and afferent neuronal pathways. RESULTS: Coronal sections of the rat ONe and corresponding olfactory bulbs showed consistent cellular and tissue damage of increasing severity that correlated with the duration of treatment with the zinc compound when compared with the control group animals. CONCLUSION: The results of this analysis indicate that the repeated oral administration of such zinc-containing compounds have neurotoxic effects on the ONe and to the mitral cells in the olfactory bulbs of treated rats. These findings point toward the need for increased investigation into the potential deleterious effects of zinc-containing compounds to humans as well.

Administration, Oral↗

PubMed1982

Wound contraction and zinc absorption during treatment with zinc tape.

Wound healing, wound contraction and zinc absorption were studied in rats operated on with excisional wounds on each side of the dorsolateral aspects of the backs. The wounds were covered with plastic foil, plastic tape or zinc tape. The shortest healing time was seen in wounds treated with plastic foil when the contralateral wound was treated with zinc tape. Final wound contraction was decreased when the wound was treated with plastic-coated tape and zinc tape that was fixed to the surrounding skin. An increase in serum zinc concentration was seen 7 days postoperatively when the animals were treated with zinc tape and a decrease in serum zinc concentration was seen at the same time when only plastic foil was used.

Animals↗

PubMed2002

The effect of dietary iron levels on changes in iron status and zinc-dependent enzyme activities in rats fed two levels of dietary zinc.

In order to determine the interrelationship between dietary iron and zinc levels, the effects of dietary iron levels (2, 10, 20, and 40 microg/g) on changes in iron and zinc status and zinc enzyme activities (aminolevulinic acid dehydratase ALA-D EC 4.2.1.24 and alkaline phosphatase ALK-P EC 3.1.3.1) in male Wistar rats were investigated using adequate and marginally deficient zinc diets (25 and 5 microg/g). When rats were fed 5 microg Zn/g diets, body weight gain and food intake remained unchanged at a Fe diet intake of 20 microg/g or greater. Similar tendencies were obtained for hemoglobin, hematocrit, plasma iron, and transferrin saturation. In contrast, liver, spleen, and femur iron concentrations increased gradually with increased iron intake. Feeding diets containing 25 microg Zn/g did not alter these parameters. The percentages of apparent iron absorption in both dietary zinc groups tended to increase with decreasing dietary iron and attained maximum levels at an Fe intake of 10 microg/g. However, In the case of rats fed Fe at concentrations of 2 microg/g Iron absorption decreased. Regardless of the dietary zinc level, rats fed diets with an Fe concentration of 2 microg/g had decreased zinc absorption and plasma ALK-P activity. However, ALA-D activity was not influenced by dietary iron.

Alkaline Phosphatase↗

PubMed1987

The effect of zinc supplements on plasma zinc and copper levels and the reported symptoms in healthy volunteers.

Information from animal studies has demonstrated the harmful effects of zinc supplementation on copper transport. Although some studies have been carried out in humans, the effect on humans has not been as well documented as the effect on animals. Forty-seven healthy volunteers (26 women and 21 men) took part in a double-blind cross-over trial which lasted for 12 weeks. The subjects were asked to take 50 mg of elemental zinc (as 220 mg zinc sulphate) or placebo, three times a day for six weeks. Venous blood was collected for the analysis of plasma levels of copper and zinc. Symptoms, which included headaches, abdominal cramps, nausea, loss of appetite and vomiting, were registered from 84% of women and 18% of men. Six female volunteers discontinued the trial; five owing to gastric irritation and one owing to consistent headaches. Plasma zinc levels rose significantly in both men and women, the increase being 36% and 57%, respectively. Plasma copper levels did not change significantly. Our study suggests that the gastric discomfort that is associated with zinc supplementation may be related to body weight as symptoms were reported from the lower-weight volunteers. Our study also shows no detrimental effect of 150 mg of zinc a day on plasma copper levels in healthy volunteers over a period of six weeks.

Adult↗

PubMed1975

[Activity of the alkaline phosphatase in the serum and bones of zinc-deficient and zinc-replenished cows].

In a study with five lactating dairy cows fed a semisynthetic diet, the changes in the activity of the alkaline phosphatase in the serum, bones and milk were investigated in response to dietary depletion and repletion of zinc. During a six-week depletion period (6 mg Zn/kg dry matter) the alkaline phosphatase in the serum decreased to only 82% of its initial level which, however, was reduced already due to a low zinc intake before the start of the study. After 19 weeks of depletion the activity had decreased to 43% of its initial level. Additions of zinc during the repletion increased the activity very clearly and to much higher values than the ones at the start of the study. Thus this effect of repletion was as large as that for the zinc content in serum and milk. The serum alkaline phosphatase indicated a dependence on the performance and represents a sensitive indicator of the zinc status. The activity of the alkaline phosphatase in the bones (Tuber coxae) decreased to 68% of its initial level after six weeks of zinc depletion. The alkaline phosphatase in the milk was not influenced by the zinc supply.

Alkaline Phosphatase↗

PubMed2001

[Effect of zinc deficiency and zinc replenishment on HOX3.5 gene expression in mouse embryos].

The effect of zinc deficiency and zinc replenishment on HOX3.5 gene expression in mouse embryos was investigated. Sixty Kunming female mice (25-30 g) were divided into three groups: zinc-deficient groups (ZD), zinc-replenished group (ZR) and zinc normal controlled group (ZN). ZD mice fed with ZD diet (Zn 3.0 +/- 0.5 mg/kg), ZN mice fed with ZN diet (Zn 30 mg/kg), and ZR mice fed with ZD diet at first and then with ZN diet from the 7th day of pregnancy. After feeding different diet for 25 days, the mice were made to copulate (female: male = 2:1). At the 12th day of pregnancy, the mice were killed and the embryos were stored at -70 degrees C. The content of mRNA of HOX3.5 in the embryos were determined by in situ hybridization with digxigenin-labeled cDNA probes. The result showed that the expression on area density and L-density (average optical density) of Hox3.5 in ZD and ZR groups were decreased in comparing with those in ZN group (P < 0.05). It was suggested that the decreased HOX3.5 gene expression by zinc deficiency might influence the normal growth of mouse embryos, and this effect might occurr in the early stage of embryo development, which can not be prevented by replenishing zinc at the 7th day of pregnancy.

Animals↗

PubMed2005

[Effects of long-term exposure of low level zinc and zn-EDTA complex on zinc accumulation and antioxidant defense system in liver of Carassius auratus].

The effects of low level zinc(Zn2+)and its EDTA complex on zinc accumulation and antioxidant enzymes,such as catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPx) in the liver of Carassius auratus are studied after 40 day exposure. The results show that zinc accumulation is significantly increased with higher zinc concentration. When fish are exposed to Zn-EDTA, the zinc accumulation in the liver of fish increased slightly according to the control. SOD, GST, CAT and GPx activity all decrease with adding to Zn2+ and Zn-EDTA in waters. However, the decrease of CAT and GPx activities of fish liver are alleviated with the addition of EDTA. The GST activities increased at lower concentration solutions ( < 0.05mg-L(-1) ), however its activities were inhibited at higher Zn2 + solution ( > 0.05mgL- ). These results suggest that CAT and GPx are more sensitive to low zinc exposure than SOD and GST, and they can be served as biomarkers of low concentration zinc exposure in aquatic ecosystem.

Animals↗

PubMed2006

[Effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats].

OBJECTIVE: To explore the effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats. METHODS: Eighty SD rats were randomly divided into C group (control group without scald, n = 8), and N, W, H groups (each consisting of 24 rats), in which the rats were exposed to scalding resulting in partial thickness burns covering 15% of the total body surface area on the back, and then they were fed with diets containing zinc 40 microg/g in N and W groups, and 80 microg/g in H group. A cream containing zinc 761.1 microg/g was applied on the wound in W group at the same time. Eight rats of each group were sacrificed on day 1, 3 and 7 after scald respectively. Venous blood and samples of liver, femur and scald skin were harvested. Zinc and calcium contents in serum and tissues were determined with atomic absorption spectrophotometer. RESULTS: The serum Zn(2+) levels in N, W groups were lower than C group, however, it was obviously higher in H group (up to 16.2 micromol/L) on day 1 after scald. The liver Zn(2+) showed an increasing tendency in all groups, while Ca(2+) level declined in H group, but increased in N, W group. The bone Zn(2+) and Ca(2+) levels showed a progressive declination in all groups from day 1 to 7 after scald. The changes were more obviously in N group than H group (P < 0.05). The Zn(2+) content of the scalded skin increased obviously in H group on first day after scald and in W group on 7th day after scald. The Ca(2+) contents of scalded skin showed marked increases in all groups, especially in N group, but least in W group. CONCLUSION: There are obvious changes in Zn(2+) and Ca(2+) contents of serum and tissues after scald injury and zinc supplementation. The effects of zinc supplementation on calcium level in the tissue need to be further studied.

Animals↗

PubMed1989

Treatment of Wilson's disease with zinc. VII. Protection of the liver from copper toxicity by zinc-induced metallothionein in a rat model.

Patients with Wilson's disease often have a further increase in hepatic copper when given zinc as an initial treatment, although there is no associated clinical deterioration. To better understand this situation an animal model was developed in which copper-loaded rats are treated with zinc administered subcutaneously. In the presence of equal amounts of copper loading in liver, control rats show hepatic damage but zinc-treated rats do not. Zinc-treated rats have much higher levels of hepatic metallothionein. Gel filtration studies reveal that much of the hepatic copper in zinc-treated rats is in this metallothionein fraction, whereas the copper in control animals is primarily associated with fractions of high or low molecular weight. Subcutaneous zinc therapy also induces intestinal, but not brain, metallothionein. We interpret these findings to indicate that zinc therapy protects against copper toxicity in liver by induction of hepatic metallothionein, which sequesters copper in a nontoxic form.

Alanine Transaminase↗