Chemical factors affecting the intestinal absorption of zinc in vitro and in vivo

Seal, Chris; Heaton, F. W.

doi:10.1079/bjn19830099

Cited by 55 publications

(33 citation statements)

References 22 publications

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“…The solubility of ZnCl2 is re ported to be very high in aqueous solution, which sug gests that this zinc salt is highly absorbable (18). Seal and Heaton (19) reported that Zn absorption did not differ between rats given diets containing ZnSO4 and ZnCl2. Because these Zn salts are frequently used as Zn sources, we presume that Zn-CPP does not improve Zn absorption in rats given a soybean protein-based diet.…”

Section: Discussionmentioning

confidence: 97%

Absorption of Zinc from Dietary Casein Phosphopeptide Complex with Zinc in Rats Given a Soybean Protein-Based Diet.

Matsui

Okumura

Yano

2002

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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SummaryThe absorption of zinc (Zn) in the form of casein phosphopeptide (CPP) com plex was compared with that of its chloride form in rats given a soybean protein-based diet. We prepared 67Zn complex with CPP (67Zn-CPP). Male rats were given a diet containing ZnCl2 in the preliminary period. After overnight food deprivation, they were fed a test meal labeled 67Zn-CPP or 67ZnCl2 (4g Zn-free diet +0.12mg 67Zn) with 0.5mg Dysprosium (Dy) as a fecal marker. Feces were collected for 5d and analyzed for 67Zn isotopic enrichment and Dy concentration with an inductively coupled plasma mass spectrometer. Fecal Dy excre tion closely paralleled that of 67Zn, and more than 89% of the administered Dy was recov ered in the feces collected for 5d. Moreover, the Zn source did not affect the excretion pat tern of 67Zn. Since Dy and 67Zn were almost excreted within 3d after the administration, the apparent absorption of 67Zn was calculated from the pooled data for 3d. The source of Zn did not affect the apparent absorption of 67Zn. These results suggested that dietary Zn in the form of CPP complex did not show higher absorbability in rats.

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Section: Discussionmentioning

confidence: 97%

Absorption of Zinc from Dietary Casein Phosphopeptide Complex with Zinc in Rats Given a Soybean Protein-Based Diet.

Matsui

Okumura

Yano

2002

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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“…Menard and Cousins (1983) used rat intestine brush border membrane vesicles and found Zn uptake tO be depressed by picolinate. However, Seal and Heaton (1983), used everted rat duodenal sacs with ZnC12 as a control, and found a fourfold increase in Zn uptake when picolinate was added to a system using a 30-fold higher concentration of zinc than was used in this study and a 50:1 ratio of PA:Zn. Others have shown that Zn absorption is not improved by the addition of picolinic acid in cattle (Flagstad, 1981), sheep (Ivan and Lamand, 1981) or pigs (Hill et al, 1986).…”

Section: Resultsmentioning

confidence: 99%

Influence of Picolinic Acid on the Uptake of 65Zinc-Amino Acid Complexes by the Everted Rat Gut

Hill

Peo

Lewis

1987

Journal of Animal Science

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Three hundred fifty rats were used in three experiments to: 1) validate the everted gut procedure as an in vitro technique for estimating Zn absorption, 2) determine the effect of increasing ratios of picolinic acid (PA) to Zn on Zn absorption and 3) determine the effect of PA on absorption of Zn and amino acid complexes at pH 6, 7 and 8. In the first experiment the time delay between tissue collection with subsequent storage in ice-cold saline and start of tissue incubation was 0, 10, 20 or 30 min. A linear decrease was observed for 6s Zn uptake with increasing delay time. Lysine absorption was not affected by delay time. In the second experiment, molar ratios of PA:Zn of 0, .5, 1.0, 1.5, 2.0 and 2.5 with Zn held constant were evaluated. A linear decrease in 6s Zn absorption from 6s ZnCI: occurred as the molar ratio of PA to Zn increased. In the third experiment, 0 and 5 molar ratios of PA to a constant Zn level were evaluated using 6s ZnCI2, 6SZn-14C-methionine (ZnMet) and 6SZn-3H-lysine (ZnLys) at pH 6, 7 and 8. The addition of PA decreased Zn absorption regardless of Zn source. The data suggest that the Zn sources used were of similar biological value. The data do not support the theory that PA facilitates Zn absorption.

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“…However, detailed information on the intestinal absorption of zinc is likely insufficient at present. Functional studies on the intestinal absorption of zinc using preparations such as everted rat gut sacs, 15,16) the isolated vascularly perfused rat intestine, [17][18][19][20] and intestinal brush-border membrane vesicles from the small intestine of rats 21) provide evidence of saturable components of zinc transport. In most experiments, zinc absorption was measured indirectly.…”

Section: In Vitro Study On the Transport Of Zinc Across Intestinal Epmentioning

confidence: 99%

<i>In Vitro</i> Study on the Transport of Zinc across Intestinal Epithelial Cells Using Caco-2 Monolayers and Isolated Rat Intestinal Membranes

Yasuno

Okamoto

Nagai

et al. 2012

Biological & Pharmaceutical Bulletin

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The variety of physiologic and biologic functions of zinc is fascinating and could be applicable to medicine. Our previous studies demonstrated that the absorption of zinc after oral administration to rats is dose-dependent. In order to clarify the detailed mechanism of the dose-dependent in vivo absorption, the transport of zinc across intestinal epithelial cells was investigated using Caco-2 monolayers and isolated rat intestinal membranes. The permeation of zinc across Caco-2 monolayers is concentration-dependent, and both saturable and nonsaturable components are involved. The Michaelis constant and maximum transport rate for saturable transport are 11.7 μM and 31.8 pmol min 1 cm 2 , respectively; the permeability coefficient for nonsaturable trasnport is 2.37 10 6 cm s 1 . These parameters for permeation across membranes isolated from duodenum, ileum, and jejunum of rats are similar with those of Caco-2 cells. The comparison of the parameters for permeation across isolated intestinal membrane suggests that the major site of intestinal zinc absorption in rats is the duodenum. The maximum rate of zinc transport across the isolated intestinal membrane (V max ) shows no correlation with mRNA expression of ZIP4, ZIP5 or ZnT1 in rats, but shows an inverse correlation with that of metallothioneins (MTs). This finding may be partly explained by the buffering role of metallothionein in intestinal absorption. The saturable transport of zinc is not simply determined only by the influx transporter, ZIP4, since three influx and efflux transporters are involved in the transport of zinc.

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Chemical factors affecting the intestinal absorption of zinc in vitro and in vivo

Cited by 55 publications

References 22 publications

Absorption of Zinc from Dietary Casein Phosphopeptide Complex with Zinc in Rats Given a Soybean Protein-Based Diet.

Absorption of Zinc from Dietary Casein Phosphopeptide Complex with Zinc in Rats Given a Soybean Protein-Based Diet.

Influence of Picolinic Acid on the Uptake of 65Zinc-Amino Acid Complexes by the Everted Rat Gut

<i>In Vitro</i> Study on the Transport of Zinc across Intestinal Epithelial Cells Using Caco-2 Monolayers and Isolated Rat Intestinal Membranes

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