Showing papers on "Mineral absorption published in 1989"
TL;DR: At a high degree of phosphorylation (IP-6, IP-5), zinc and calcium uptake was inhibited, while no effect was observed for the other phosphates, Consequently, total "phytate" analysis, which includes inositol phosphates with varying degrees ofosphorylation, can give misleading information with regard to mineral availability.
Abstract: While it is known that phytic acid, inositol hexaphosphate, has a negative effect on zinc and calcium absorption, the effects of inositol which is phosphorylated to a lesser extent are less known. We have prepared inositol triphosphate (IP-3), tetraphosphate (IP-4), pentaphosphate (IP-5) and hexaphosphate (IP-6) by hydrolysis of sodium phytate and separation by ion-exchange chromatography and have studied their effect on zinc and calcium absorption. Using a suckling rat pup model, we found that liver uptake of 65Zn after 6 h was 5% of the total dose from solutions of IP-6, 19% from IP-5, 28% from IP-4, 29% from IP-3 and 31% from ZnCl2 (control). Non-absorbed calcium was 17%, 1.4%, 0.5%, 0.5% and 0.5% of the given dose of 45Ca, respectively. Thus, at a high degree of phosphorylation (IP-6, IP-5), zinc and calcium uptake was inhibited, while no effect was observed for the other phosphates. Consequently, total "phytate" analysis, which includes inositol phosphates with varying degrees of phosphorylation, can give misleading information with regard to mineral availability. In addition, even limited dephosphorylation of inositol hexaphosphate can have a positive effect on mineral absorption.
274 citations
TL;DR: Changes in skeletal mass, nutritional calcium and phosphorus balance, and intestinal calcium absorption were studied in four groups of rats: control, exercise allowing free access to food, exercise with pair-feeding to control levels, and immobilization.
Abstract: Changes in skeletal mass, nutritional calcium and phosphorus balance, and intestinal calcium absorption were studied in four groups of rats: control, exercise allowing free access to food, exercise with pair-feeding to control levels, and immobilization. The exercise regimen consisted of treadmill running 25 m/min, 60 min/day, 5 days/wk for 13 wk; rats were immobilized by bilateral sciatic denervation. The total body Ca (TBCa) was measured by neutron activation analysis as an index of skeletal mass. Standard metabolic balance techniques were used to determine calcium and phosphorus balance, and an in situ duodenal loop ligation preparation was used to study the active and passive intestinal Ca transport processes. Exercise promoted a positive Ca and P balance and increased the skeletal mass, largely as a result of an increase in 1,25-dihydroxyvitamin D and an enhancement of the intestinal Ca absorption efficiency. Urinary excretion of Ca and P did not differ from control levels and food intake was not a factor because pair-fed rats responded to exercise almost identically to those fed ad libitum. Conversely, immobilization caused a decrease in TBCa and a lower Ca and P balance. These effects are the result of an increased urinary mineral excretion, greater endogenous fecal excretion, and decreased mineral absorption efficiency in the intestine.
55 citations
TL;DR: In this article, the effects of rootstock on the yield of eggplant in relation to the number of thick roots, mineral flux and hormone levels in xylem sap were investigated.
Abstract: Eggplants, cv. Hayabusa, Kokuyou and Beikokudaimaru, grown either on their own roots or on the rootstocks, cv. VF, Akanasu and Torubamu, were used to study the effects of rootstock on the yield of eggplant in relation to the number of thick roots, mineral flux and hormone levels in xylem sap.1. All of three varieties grafted on VF showed the highest yield and the most vigorous growth, and more thick roots were found on those plants. Own-root plants produced lower yields with fewer thick roots than grants. There was a close positive correlation between the number of thick roots and yield.2. Xylem exudation rate and mineral flux in xylem sap were the highest in the plants grafted on VF. The mineral flux, especially nitrogen, was closely correlated with yield.3. Cytokinin, gibberellin-like substances and indole-acetic acid levels were the greatest in the xylem sap of plants grafted on VF rootstock, which produced the highest yield. The difference in yield between rootstocks was significantly attributed to difference in cytokinin production, depending on the number of thick roots.4. From these results, it may be concluded that the growth and yield of eggplant was affected by mineral absorption and hormones especially cytokinin production of rootstocks via many thick roots.
33 citations
TL;DR: The present work addresses the issue of “To what extent might a plant-derived macromolecular complex (i.e., plant cell walls) impede mineral absorption?”
Abstract: Investigations into the relationship between dietary fiber content and mineral-nutrient bioavailability of diets have generally shown an inverse relationship (Munoz, 1986). The inhibitory effect of fiber on mineral absorption, although perhaps more appropriately attributed to phytic acid in some studies, thus seems well established. The process by which fiber exerts its inhibitory effect is less well characterized. Three modes of inhibition have been hypothesized (Kelsay, 1981): 1) fiber greatly increases fecal bulk and motility, thus reducing the time available for absorption or access to transport mechanisms; 2) fiber directly or indirectly alters luminal-to-serosal transport mechanisms in the mucosa (such as the ferritin system); 3) the formation of stable, unabsorbable mineral-fiber complexes reduces the pool of available minerals. The latter hypothesis, utilized by most investigators, as well as in this work, posits that minerals bound to large macromolecules can not be absorbed directly nor transfer to mineral-transporter moieties. Thus, within the context of the subject matter of these proceedings, the present work addresses the issue of “To what extent might a plant-derived macromolecular complex (i.e., plant cell walls) impede mineral absorption?”
19 citations
01 Jan 1989
TL;DR: Theoretical and practical aspects of zinc uptake and absorption were discussed in this article, where the authors determined using In Vivo Tracer Studies and Kinetic Analysis that zinc uptake in humans was determined using EDX analysis.
Abstract: Section I. Mechanisms of Mineral Absorption -- 1. Theoretical and Practical Aspects of Zinc Uptake and Absorption -- 2. Zinc Absorption in Humans Determined Using In Vivo Tracer Studies and Kinetic Analysis -- 3. Mechanisms of Intestinal Brush Border Iron Transport -- 4. Trace Metal Interactions Involving the Intestinal Absorption Mechanisms of Iron and Zinc -- 5. On the Molecular Mechanisms of Intestinal Calcium Transport -- 6. Equilibration Constants for the Complexation of Metal Ions by Serum Transferrin -- Section II. Dietary Influences on Mineral Uptake -- 7. Protein Digestion and the Absorption of Mineral Elements -- 8. The Effect of Dietary Proteins on Iron Bioavailability in Man -- 9. Effect of Gastrointestinal Conditions on the Mineral-Binding Properties of Dietary Fibers -- 10. In Vivo Mineral Contents of Dietary Fiber Determined by EDX Analysis -- 11. Phytic Acid Interactions with Divalent Cations in Foods and in the Gastrointestinal Tract -- 12. Low Gastric Hydrochloric Acid Secretion and Mineral Bioavailability -- 13. Effect of Age and the Milk Sugar Lactose on Calcium Absorption by the Small Intestine -- 14. Dietary Fiber or Bile-Sequestrant Ingestion and Divalent Cation Metabolism.
19 citations
TL;DR: Results indicate that lysocellin and monensin alter apparent absorption and retention of certain minerals in steers fed forage-based diets.
Abstract: Studies were conducted to determine the effects of lysocellin and monensin on mineral metabolism of steers fed forage-based diets. In each study treatments consisted of 1) control, 2) 100 mg lysocellin/d, 3) 200 mg lysocellin/d and 4) 200 mg monensin/d. Twenty-four growing Hereford steers were used in each of two experiments to evaluate the effects of ionophore feeding on plasma and ruminal soluble mineral concentrations. Steers were fed individually greenchop (tall fescue and bermudagrass) ad libitum and .91 kg/d of a corn-trace mineral salt-ionophore supplement. Plasma and ruminal fluid samples were obtained on d 28 and 84 in both studies. Ruminal concentrations of soluble phosphorus (P) and iron (Fe) were higher (P less than .05), whereas soluble manganese (Mn) was lower (P less than .01), in steers fed lysocellin than in controls. Steers fed lysocellin had higher (P less than .05) plasma magnesium (Mg) concentrations than control steers. Plasma and ruminal soluble mineral concentrations generally were similar for the monensin and 200 mg lysocellin treatments. Two additional studies were conducted to determine the effects of lysocellin and monensin on macromineral apparent absorption and retention in steers fed tall fescue greenchop. Steers were adjusted to their diets for 28 d and then placed in metabolism crates for a 6-d acclimation followed by a 5-d collection of urine and feces. Percent apparent absorption of calcium (Ca), potassium (K), Mg and P was higher (P less than .05), whereas sodium (Na) absorption was lower (P less than .05), in steers fed lysocellin than in controls. Mineral absorption was similar in steers fed 200 mg lysocellin or monensin. Calcium (P less than .05) and K (P less than .10) retention (percent of intake) was increased by ionophore feeding. Results indicate that lysocellin and monensin alter apparent absorption and retention of certain minerals in steers fed forage-based diets.
16 citations
Patent•
28 Jun 1989
TL;DR: In this article, a food and drink containing a mineral (preferably Ca, Fe, Mg, Zn or Cu) and poly-α- or polyγ-glutamic acid as a mineral absorption promoter is presented.
Abstract: PURPOSE: To obtain the subject food and drink, containing a mineral and poly-α- or poly-γ-glutamic acid as a mineral absorption promoter, capable of increasing the soluble mineral concentration in intestinal tracts and useful for preventing osteopathy, etc. CONSTITUTION: The objective food and drink containing a mineral (preferably Ca, Fe, Mg, Zn or Cu) and poly-α- or poly-γ-glutamic acid as a mineral absorption promoter. COPYRIGHT: (C)1991,JPO&Japio
12 citations
TL;DR: EDX measurements of the mineral content of oat hulls in the pig GI tract revealed that the hulls from the rectum contained more Na, P and S than prior to ingestion; while contents of K and Ca were not significantly different than in initial hulls.
Abstract: In the past fifteen years there has been extensive research into relationships between the dietary fiber content of human and animal diets and health and nutrition. A continuing concern is that binding of minerals to dietary fiber may impair mineral bioavailability (Kies, 1985; Sandstrom et al., 1987). The in vitro binding of elements such as Ca, Fe, Mg, and Zn to various fiber substrates has been reported (Camire & Clydesdale, 1981; Reinhold et al., 1981). Numerous feeding studies in recent literature (reviewed by Kelsay, 1986) also address questions of effects on mineral bioavailability of dietary fiber in human and animal diets. An interesting question is whether or not the plant cell walls of the dietary fiber source impede mineral absorption by acting as mineral sinks that remove significant amounts of cations from the intestinal lumen. However, there are relatively few studies that examine changes in the mineral content of such tissues to directly measure in vivo mineral binding.
1 citations