Absorption with minerals

Proteins and Meals. Nutritional properties of the oilseed protein meals and their derived products are deterrnined by the amino acid compositions, content of biologically active proteins, and various nonprotein constituents found in the defatted meals. Phytic acid (3), present as salts in all four meals, is beheved to interfere with dietary absorption of minerals such as 2inc, calcium, and iron (67) (see Food toxicants, naturally occurring Mineral nutrients). ... 

Lower water absorption, especially with mineral-filled resins. 

Generally used with mineral wool products where, in its decorative forms, it gives attractive facings to ceilings and wall tiles and enhances their sound-absorption characteristics. PVC is also used as a vapor control layer facing. 

Minerals generally present difficult problems in chemical analysis, and these problems grow more serious when the elements being determined are as difficult to separate as are those named above. The time and effort that x-ray emission spectrography can save are therefore great, but there are obstacles to be surmounted. Among these are (1) Absorption and enhancement effects are often serious. (2) The element of interest may be present at low concentration in a matrix that is unknown and variable. (3) Satisfactory standards are not always easy to obtain. (4) Simple equipment sometimes does not resolve important analytical lines- completely. (5) Sample preparation and particle size often influence the intensities of analytical lines Class II deviations (7.8) can be particularly serious with minerals. 

Allelopathic inhibition of mineral uptake results from alteration of cellular membrane functions in plant roots. Evidence that allelochemicals alter mineral absorption comes from studies showing changes in mineral concentration in plants that were grown in association with other plants, with debris from other plants, with leachates from other plants, or with specific allelochemicals. More conclusive experiments have shown that specific allelochemicals (phenolic acids and flavonoids) inhibit mineral absorption by excised plant roots. The physiological mechanism of action of these allelochemicals involves the disruption of normal membrane functions in plant cells. These allelochemicals can depolarize the electrical potential difference across membranes, a primary driving force for active absorption of mineral ions. Allelochemicals can also decrease the ATP content of cells by inhibiting electron transport and oxidative phosphorylation, which are two functions of mitochondrial membranes. In addition, allelochemicals can alter the permeability of membranes to mineral ions. Thus, lipophilic allelochemicals can alter mineral absorption by several mechanisms as the chemicals partition into or move through cellular membranes. Which mechanism predominates may depend upon the particular allelochemical, its concentration, and environmental conditions (especially pH). 

One of the primary bases for the hypothesis that allelochemicals affect mineral uptake rests with the fact that the concentration of minerals In receiver plants can be altered by donor plants by a mechanism other than competition for minerals. In general, studies In support of this hypothesis have Involved measuring the amount of mineral present per weight of a particular plant part following absorption of minerals by the roots of the Intact receiver. 

Effects of Allelochemlcals on ATPases. Several flavonoid compounds inhibit ATPase activity that is associated with mineral absorption. Phloretin and quercetin (100 pM) inhibited the plasma membrane ATPase Isolated from oat roots (33). The naphthoquinone juglone was inhibitory also. However, neither ferulic acid nor salicylic acid inhibited the ATPase. Additional research has shown that even at 10 mM salicylic acid inhibits ATPase activity only 10-15% (49). This lack of activity by salicylic acid was substantiated with the plasma membrane ATPase Isolated from Neurospora crassa (50) however, the flavonols fisetln, morin, myricetin, quercetin, and rutin were inhibitory to the Neurospora ATPase. Flavonoids inhibited the transport ATPases of several animal systems also (51-53). Thus, it appears that flavonoids but not phenolic acids might affect mineral transport by inhibiting ATPase enzymes. 

Polyalphaolefin Hydraulic Fluids. No studies were located regarding absorption in humans or animals after inhalation exposure to polyalphaolefin hydraulic fluids or their major components. Based on physicochemical similarities with mineral oils (i.e., long-chain aliphatic hydrocarbons are predominant... 

Dihydroepistephamiersine 6-acetate (7) was isolated from Stephania abyssinica as a homogeneous oil. The UV spectrum showed an absorption maximum at 286 nm, and the IR spectrum exhibited a band corresponding to an aliphatic ester carbonyl group at 1725 cm-1 (20). The H-NMR data are summarized in Table II. In chemical investigations, hydrolysis of 7 with barium methoxide gave an alcohol identical with 6-dihydroepistephamiersine (17), which on further treatment with mineral acid gave the known alkaloid, stephasunoline (17). Thus structure 7 was proposed for 6-dihydroepistephamiersine 6-acetate (20). 

Various atomic absorption spectrophotometric procedures have been described for the determination of mercury in soils. Methods based on attacking the mercury in soil samples with mineral acids and permanganate have been shown to give low mercury recoveries. In recent years methods based on decomposition of the sample by heating have gained favour in that they obviate any tendency to produce low results. 

Growth regulators can influence a plant s absorption of minerals from the soil. The uptake of potassium by wheat, for example, is accelerated by treating the plant with gibberellic acid. The uptake of both nitrogen and phosphorus by wheat and soybean plants is enhanced by treatment with 2,4-D. 

The behavior of minerals is often influenced by the presence of other food constituents. The recent interest in the beneficial effect of dietary fiber has led to studies of the role fiber plays in the absorption of minerals. It has been shown (Toma and Curtis 1986) that mineral absorption is decreased by fiber. A study of the behavior of iron, zinc, and calcium showed that interactions occur with phytate, which is present in fiber. Phytates can form insoluble complexes with iron and zinc and may interfere with the... 

The Isolated, vascularly perfused rat intestine system has been used to investigate the influence of various zinc-binding ligands on zinc absorption. With this approach the functional integrity of the intestine with respect to several minerals, including calcium, iron and zinc uptake, and subsequent transfer of these minerals to their respective serum transport proteins is maintained (32,33). The intestinal perfusion system allows the simultaneous measurement of both mucosal zinc uptake (retention) and transfer to the portal circulation (absorption), and thus provides detailed information on the nature of the mechanisms of both uptake from the lumen and transfer to albumin in the portal circulation. 

Saturated fatty acids are better absorbed as MAGs than as FFA, as the latter can form less-absorbable hydrated acid soaps and complexes with calcium and other divalent ions (41). The effect is more pronounced when the amount of calcium in the diet is high (42). In the presence of insoluble soaps, cholesterol absorption may be reduced (43). Thus, the stereospecific position of fatty acids in the TAGs can have an effect on their absorption and on the absorption of minerals and other lipid constituents. 

The proposed method to process these wastes [11, 13], shown schematically in Fig. 1, consists of leaching them with hot water (1), filtrating (2), treating with mineral acid to pH 3-5 (released nitrous oxides are fixed in the absorption tower), alkalization with ammonia water to pH 7-8 (4), precipitation with the soluble calcium salt to calcium molybdate (5) filtration and washing (6) of the precipitate (7) which can be processed (8) to other molybdenum compounds (9). 

Warfarin The exact warfarin-quinolone drug interaction is unknown. Reduction of intestinal flora responsible for vitamin K production by antibiotics is probable, as are deaeased metabolism and clearance of warfarin due to CYP450 inhibition by the quinolones. Multivalent cations such as aluminum, magnesium, calcium, iron, zinc, and multivitamins with minerals may chelate with fluoroquinolones and decease the oral absorption if administered concurrently. 

Docusate salts are absorbed from the gastrointestinal tract and excreted in bile they may cause alteration of the gastrointestinal epithelium. The gastrointestinal or hepatic absorption of other drugs may also be affected by docusate salts, enhancing activity and possibly toxicity. Docusate sodium should not be administered with mineral oil as it may increase the absorption of the oil. 

---