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PubMed1988

Nutritional status and phytate:zinc and phytate x calcium:zinc dietary molar ratios of lacto-ovo vegetarian Trappist monks: 10 years later.

A nutrition assessment of 16 members of a community of lacto-ovo vegetarian Trappist monks was conducted in 1977. Plasma zinc was found to be low-normal, which was attributed primarily to high intakes of phytate-containing foods. Individual and group counseling were instituted over a 10-year period in an attempt to emphasize the importance of wise food selection within the constraints of lacto-ovo vegetarianism. In 1987, a more comprehensive nutrition assessment of 21 members of the same community was performed. Food composites were analyzed, and 3-day instead of 24-hour dietary records were kept. Intakes of phytate-containing foods had decreased from 4,569 to 972 mg/day; intake of dietary zinc had increased from 7.4 to 9.7 mg/day; and the phytate:zinc molar ratio had decreased from 67 to 14 for the years 1977 and 1987, respectively. An analyzed phytate:zinc molar ratio of 9.8 and an analyzed phytate x calcium:zinc molar ratio of 0.3 were representative of the 1987 community. Both were within normal ranges. Plasma zinc had risen to upper-normal levels. The 1987 nutrition assessment showed that it is possible to be adequately nourished with a lacto-ovo vegetarian diet provided one has proper knowledge of the phytate-containing foods and the methods for compensating with foods of greater mineral density (primarily zinc).

Adult↗

PubMedDate not supplied

Dual action of zinc on ileal smooth muscle--zinc-calcium interaction.

Effect of zinc sulphate was studied on histamine-induced contractions on guinea-pig ileum. In doses of 1.72 X 10(-7)M or less no effects were observed. Zinc sulphate in doses of 3.44 X 10(-7)M, 6.88 X 10(-7)M and 1.72 X 10(-6)M produced dual effect. Short exposure of tissue for 10 min to zinc sulphate resulted in significant dose dependent potentiation of histamine effect whereas after washing the tissue of zinc sulphate, histamine response was inhibited significantly and in a dose dependent manner. Higher concentrations of zinc sulphate of 3.44 X 10(-6)M and above produced irreversible inhibition of histamine response. The above observations have been explained in terms of zinc-calcium interaction. It is hypothesized that interaction of zinc with calcium may take place extracellularly at membrane level and intracellularly.

Animals↗

PubMedDate not supplied

[Zinc in prostatic physiopathology. I. Role of zinc in the physiology and biochemistry of the prostatic gland].

To sum up the role of zinc in prostatic physiology and biochemistry: a) Zinc is found in normal prostate tissue in a greater concentration than in any other organ in the economy, ranging between 0.70 and 1 mgm/gm. of dry tissue. b) The concentration of prostate liquid and semen is greater than that in any other organic liquid. c) It appears that the prostate gland is a zinc storing organ (or deposit). d) The zinc concentration in prostatic tissue is directly proportional to the amount of alveolar tissue existing in the gland. e) It has been shown that the Zn concentration is greater in the nuclear sediment of the different subcellular fractions of the human prostate gland. f) The prostate gland seems to supply zinc to the human sperm and plays an important role in the metabolic activity of the spermatozoid. g) There seems to be a clear difference between the distribution and absorption of radioactive zinc in the different lobes of the prostate gland. h) Zinc also plays an important part in the enzymatic activity of the prostate gland and in the polymeric organization of the RNA and DNA and is vital for cell division. i) Prostatic Zn has a clear hormonal dependency.

Humans↗

PubMedDate not supplied

Effect of oral zinc sulphate and penicillamine on zinc metabolism in patients with rheumatoid arthritis.

Whole body zinc and zinc absorption were measured in 14 patients with classical rheumatoid arthritis (RA). Half of these patients were treated with penicillamine for a period of 8 wk and the other half received zinc sulphate orally for a similar period of time. Whole body zinc and zinc absorption were not significantly affected by either therapy. These observations suggest that any pharmacological effect of oral zinc sulphate or penicillamine on patients with RA is not mediated by their effect on zinc metabolism in such patients.

Administration, Oral↗

PubMed1995

The Ig-related killer cell inhibitory receptor binds zinc and requires zinc for recognition of HLA-C on target cells.

Members of the Ig superfamily are predominantly receptors that mediate interactions between cells or provide signals to cells when binding specific ligands. Here we describe an Ig-related receptor that requires zinc for its function. Killer cell inhibitory receptors (KIR) belonging to the Ig superfamily mediate inhibition of NK cells upon recognition of HLA-C molecules on target cells. An abundance of histidine residues in the first extracellular domain of KIR, including the signature zinc binding motif HEXXH, suggested that this receptor may bind zinc. Two distinct KIR molecules that mediate recognition of HLA-Cw4 and -Cw8, respectively, bound specifically to zinc affinity columns. Furthermore, addition of the zinc chelator 1,10-phenanthroline during chromium release assays reversed the inhibition of killing by NK clones specific for HLA-Cw4 or HLA-Cw8, demonstrating that zinc is necessary for the inhibitory function of KIR. Such functionally relevant zinc binding has not been described for other members of the Ig superfamily and may represent a novel regulatory mechanism for Ag receptor-ligand interactions.

Amino Acid Sequence↗

PubMed1978

Local absorption of zinc from wounds treated with various zinc-compounds.

It is shown that in the rat, zinc is absorbed from excisional wounds into serum, from various locally applied zinc oxide preparations as well as from zinc peroxide and zinc sulphate. The most pronounced absorption of zinc to serum was recorded from wounds treated with zinc peroxide. Microscopically the cellular inflammatory response observed in wounds treated with a gauze sponge impregnated with a zinc sulphate solution was weaker than that found with the other treatment methods used.

Absorption↗

PubMed2006

Bioavailability of zinc glycinate in comparison with zinc sulphate in the presence of dietary phytate in an animal model with Zn labelled rats.

The objective of this study was to quantify the bioavailability of zinc (Zn) from sulphate and glycinate as representatives of inorganic and organic zinc sources. The semi-synthetic basal diet contained 2 microg/g of native Zn and was fortified with pure sodium-phytate (8 g/kg) in order to simulate conditions of common cereal-based meals. The basal diet was supplemented with either 53 microg/g of Zn from sulphate (control) or 10 microg/g of Zn from either sulphate (ZnSulphate) or glycinate (ZnGly). Twenty-four (65)Zn-labelled, growing rats weighing 133 g were allotted to the three diets (eight animals per treatment) and were kept pair-fed to ZnSulphate for 15 days. Zn contents in blood plasma, femur and whole body, as well as, plasma alkaline phosphatase activities were reduced compared with control indicating a zinc deficiency in ZnSulphate and ZnGly treatment. This allowed their differentiation in zinc bioavailability. True absorption of dietary Zn was significantly higher in ZnGly than in ZnSulphate (51% vs. 44%) while losses of endogenous faecal Zn and urinary Zn were not affected to a quantitatively relevant extent (mean: 17% and 2% of intake). This resulted in a +30% significantly improved Zn retention for ZnGly (33% vs. 25%) and a lower severity on Zn deficiency symptoms compared with ZnSulphate. Metabolic utilization accounted for 95% of absorbed dietary Zn for both Zn sources. Overall, the bioavailability of zinc glycinate was significantly superior by 16% to zinc sulphate (49% vs. 42%), mainly because of a higher absorptive potential at presence of a strong anti-nutritive component (phytate) in the diet.

Animal Feed↗

PubMed1993

Correction of cellular zinc depletion by oral zinc supplementation in elderly subjects.

Immune function declines with age, and has been implicated in the increased incidence of cancer and infections in the elderly. In this hospital, many elderly patients have evidence of zinc depletion. In the present study, we supplemented those elderly patients who had depressed polymorphonuclear cell (PMNC) zinc levels with 135 mg oral zinc sulphate for 4 weeks. Plasma and PMNC zinc increased markedly but the percentage of peripheral blood T-lymphocytes expressing the surface markers CD3, CD4 and CD8 were unchanged. Plasma concentrations of vitamins A and E also remained constant. This study confirms the 25-30% incidence of cellular zinc depletion in this patient population, and demonstrates that zinc concentrations can be brought back to within normal limits by oral zinc supplements, but with no effect on T-cell phenotypes.

Journal Article↗

PubMed1985

Zinc absorption and leukocyte zinc in alcoholic and nonalcoholic cirrhosis.

To determine if malabsorption of zinc contributes to the zinc deficiency found in cirrhosis, the absorption of an oral dose of ZnCl2, labeled with 65Zn and a nonabsorbed marker 51CrCl3, was determined from the ratio of these isotopes in a stool specimen. Average 65Zn absorption in 25 alcoholic cirrhotics, 37 +/- 17% (SD), was low compared to 55 +/- 16% in 31 healthy volunteer controls (P less than 0.01). In contrast, mean 65Zn absorption, 47 +/- 11%, in 11 nonalcoholic cirrhotics was not significantly different from the average result in healthy controls. Low 65Zn absorption was accompanied by low leukocyte zinc in a subgroup of alcoholic cirrhotics with ascites and/or ascites and encephalopathy, but not in the subgroup in which these clinical features were absent. Thus, low zinc absorption contributes to zinc deficiency in decompensated alcoholic cirrhosis. The failure to find similar abnormalities in nonalcoholic cirrhosis suggests that the long-standing consumption of alcoholic beverages contributes to the malabsorption of zinc.

Adult↗

PubMed1990

The nucleocapsid protein isolated from HIV-1 particles binds zinc and forms retroviral-type zinc fingers.

The role of zinc in retroviral gag protein function has been addressed through the application of high-resolution nuclear magnetic resonance spectroscopy to samples of the nucleocapsid protein (NCP, p7) isolated directly from infectious HIV-1 particles. Unlike reports for the NCP from avian myeloblastosis virus (AMV) particles [Jentoft et al. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7094], we find that the HIV-1 NCP binds 2 equiv of zinc tightly and stoichiometrically. Two-dimensional NMR spectroscopic studies reveal that zinc binding induces formation of folded domains that are conformationally similar to (if not identical with) structures observed previously for relevant retroviral-type (RT) zinc finger peptides [formerly called zinc fingerlike peptides; Summers et al. (1990) Biochemistry 29, 329]. This finding is consistent with the hypothesis that the inability of mutant proteins (with substituted Cys and His residues) to package viral RNA results from deficient zinc-binding capability, which may have significant consequences in the development of vaccines for the prevention of AIDS.

Amino Acid Sequence↗

PubMed2006

Zinc metalloregulation of the zinc finger pair domain.

The yeast transcriptional activator Zap1 contains two uncommon structural motifs designated zinc finger pair domains. The hallmark of this domain is the packing of two zinc finger motifs in one globular unit. One finger pair domain in Zap1 contains the AD2 transactivation domain. Zn(II) binding to this domain (ZF1/2) is kinetically labile yielding a zinc-regulated transactivator. The second finger pair domain (ZF3/4) lies within the DNA-binding domain, and it stably binds Zn(II). The goal of this study was to map the determinant conferring lability in Zn(II) binding by using finger pair chimeras. Whereas ZF2 contains the transactivation function, zinc regulation is dependent on the presence of ZF1. ZF3 can functionally replace ZF1, and a ZF3/2 finger pair retains limited zinc regulation. Replacement of ZF3 by ZF1 creating a ZF1/4 chimera was found to stably bind Zn(II), suggesting that the presence of a stable motif (ZF4) can impart binding stability on a labile motif (ZF1). Zn(II) binding in finger pair domains is dependent on the presence of both motifs. Mutations in one finger motif markedly attenuate Zn(II) binding to the second motif. Kinetic lability in Zn(II) binding was mapped to the alpha-helix of ZF2. A ZF1/ZFbeta2alpha4 chimera resembles ZF3/4 in Zn(II) binding stability in incubation studies with the Zn(II) chelators. The present results demonstrate that zinc regulation of AD activity of ZF2 is dependent on determinants in ZF1 as well as the alpha-helix segment of ZF2.

Amino Acid Motifs↗

PubMed2000

Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds.

Two clinical trials were conducted, one involving 273 subjects with experimental rhinovirus colds and the other involving 281 subjects with natural colds. Symptomatic volunteers were randomized to receive oral lozenges containing zinc gluconate (13.3 mg), zinc acetate (5 or 11.5 mg), or placebo. The median duration of illness in zinc gluconate recipients was 2.5 days, contrasted with 3.5 days in the placebo recipients (P=.035), in the experimental colds study. Zinc gluconate had no effect on symptom severity and zinc acetate had no effect on either duration or severity. Neither formulation had an effect on the duration or severity of natural cold symptoms. Evaluation of blinding, taste, and adverse events revealed no significant differences among the 4 treatment arms. Zinc compounds appear to have little utility for common-cold treatment.

Adolescent↗

PubMed1985

Zinc absorption in alcoholics using zinc-65.

Alcoholism is occasionally complicated by zinc deficiency. We have assessed the possibility that malabsorption of zinc may be a potential cause. Using a dual isotope absorption technique the absorption of 65Zn in 18 alcoholic patients was 37% (13 +/- SD) and 56% (10 +/- SD) in a normal control group (p less than 0.001). The mean serum zinc in 55 alcoholic patients was 11.6 mumol/l (3.0 +/- SD) and in 36 normal volunteers the mean serum zinc was 13.6 mumol/l (1.8 +/- SD; p less than 0.001). This study suggests that chronic alcohol abuse will decrease the absorption of zinc and this may contribute towards the zinc deficiency occasionally associated with alcoholism.

Absorption↗

PubMed1990

[The zinc concentration in the dental plaque after zinc chloride mouth rinsing in relation to previous mouth rinsings with different pH values].

The zinc content in dental plaque after mouth rinsing with 0.2% zinc chloride solution is dependent on previous mouth rinsing with different pH value. Zinc retention is strongly reduced by rinsing with citric acid solution (pH value 1.0). Zinc retention is growing with increasing pH value when rinsing was made with sodium citrate buffer solution with increasing pH value. A rinsing with sodium citrate buffer solution (pH value 6.3) following a 0.2% zinc chloride solution leads to a drastic reduction of the zinc content. However, a chlorhexidine solution with the same pH value leaves no washing out effect.

Buffers↗

PubMedDate not supplied

Effect of zinc administration on seminal zinc and fertility of oligospermic males.

Fourteen infertile males (age 24-45 years; married over 2 years) with idiopathic oligospermia (sperm count less than 40 millions/ml) were investigated for the effect of oral zinc sulphate (220 mg) for 4 months on their serum and seminal zinc levels, and seminal parameters. With zinc administration serum zinc levels remained essentially unaffected, however, seminal zinc levels increased significantly. There was significant improvement in sperm count, number of progressively motile and normal spermatozoa, and acid phosphates activity. Wives of 3 patients conceived. Observations suggest that zinc has potential to be used in male infertility. However, further studies are warranted.

Adult↗

PubMed1983

[Clinical studies on zinc oxide ointment replacing boric acid and zinc oxide ointment (JP8)].

A boric acid and zinc oxide ointment (J.P. VIII) is an unique preparation in Japan, which consist of boric acid (5%), zinc oxide (10%), vegetable oil (usually soybean oil or sesame oil) and yellow wax. The ointment is widely used in the area of Hokkaido, because not only of the customary prescription but also of the characteristic clinical efficiency. However, boric acid has been recognized to be harmful in these days. Therefore, a zinc oxide ointment consisting 10% zinc oxide, soybean oil and white beeswax was tentatively made and evaluated. The zinc oxide ointment presented the same consistency as the boric acid and zinc oxide ointment, measured with penetrometer. The clinical efficiency was also confirmed on six patients with chronic eczema and seven patients with psoriasis vulgaris. The effect on wound healing of the donor site of skin graft was as good as the previous preparation.

Boric Acids↗

PubMed1979

Zinc inhibition of calmodulin: a proposed molecular mechanism of zinc action on cellular functions.

Calcium stimulates, and zinc inhibits, a wide variety of cell types. In the erythrocyte, we have found calcium and zinc to have antagonist actions in a variety of systems. An important mechanism for calcium effects on cells is activation of calmodulin. Calmodulin is a small ubiquitous protein which, when activated by calcium, has a large array of cellular regulatory functions. We now report that calmodulin function is inhibited by low concentrations of zinc. Zinc inhibition of calmodulin provides a rational molecular mechanism for the diverse cellular inhibitory effects of zinc, as well as for zinc's antagonism of calcium effects.

Adenosine Triphosphatases↗

PubMed1989

Role of zinc in regulating the testicular function. Part 2. Effect of dietary zinc deficiency on gonadotropins, prolactin and testosterone levels as well as 3 beta-hydroxysteroid dehydrogenase activity in testes of male albino rats.

Induced zinc deficiency in male albino rats caused a great reduction in the testicular levels of testosterone as compared to control and zinc-supplemented (ZS) rats. Estimation of the testicular levels of follicle-stimulating hormone, luteinizing hormone and prolactin (PRL) in the zinc-deficient (ZD) rats showed higher levels in comparison with both control and zinc-supplemented rats. However, the increase in PRL levels was statistically insignificant. A great reduction in the activity of 3 beta-hydroxysteroid dehydrogenase, an important enzyme involved in testosterone biosynthesis, was demonstrated histochemically in the testes of ZD rats as compared to both control and ZS ones. These results reflect a direct action of zinc deficiency on the testicular steroidogenesis and strongly support the idea that the hypogonadal state associated with zinc deficiency results mainly from some alteration in the testicular steroidogenesis or in other words Leydig cell failure.

3-Hydroxysteroid Dehydrogenases↗