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Blood plasma, metal complexes

The tetracyclines Form an important group of antibiotics. The activity appears to result from their ability to chelate metal ions since the extent of antibacterial activity parallels the ability to form stable chelates. The metal in question appears to be magnesium or calcium since the addition of large amounts of magnesium can inhibit the antibiotic effects. In addition, it is known that in blood plasma the tetracyclines exist as calcium and magnesium complexes.,JS... [Pg.1012]

Trimethylenediamine, N-(2-aminoethyl)-metal complexes, 49 Tripeptides metal complexes blood plasma, 966... [Pg.1102]

Citrate Since it occurs to the extent of about 0.1 nM in the blood plasma, citrate becomes the pre-eminent small molecule plasma binder of a metal ion like Al3+ that prefers oxygen donor ligands. Citrate complexion of Al3+ in the upper gastrointestinal tract with a pH of 2 to 5, may form a zero-charged complex that may pass through membranes. Sodium citrate as well as calcium citrate may cause a 100-fold enhancement of gastrointestinal Al absorption. The adsorption of Al from Al(OH)3-based antacid rises substantially upon intake of citrate, and therefore these antacids should not be taken with citrus fruit or juices [190]. [Pg.36]

May P. M., Linder P. W., and Williams D. R. (1977) Computer simulation of metal-ion equilibria in biofluids models for the low-molecular-weight complex distribution of calciu-m(II), magnesium(II), manganese(II), iron(III), copper(II), zinc(II), and lead(II) ions in human blood plasma. J. Chem. Soc. Dalton Trans. 588—595. [Pg.4849]

Several of these hydroxy complexes may polymerize to form a chain whereby the hydroxide ion acts in a bridging role. Such hydroxy-bridged polymers are found when heavy metals, such as plutonium, or the other actinides, enter into the lungs or blood plasma and then become deposited as insoluble metal hydroxy polymers. [Pg.35]

The major side effect of chelation therapy, particularly with EDTA, is hypocalcaemia, a condition caused by too rapid administration of the chelator. The result is a rapid drop in the ionized calcium in the blood plasma that causes muscle and abdominal cramps, convulsions, and even death. The condition is usually controlled by infusion of calcium gluconate, or prevented when the metal to be removed complexes with a much higher stability constant with EDTA than that of the Ca-EDTA, by administration as the Ca-EDTA complex. [Pg.89]

EDTA forms stable complexes with Ca and Mg ions in aqueous solution. Ca and Mg are present in blood plasma at about 2.2-2.5mmol 1 and 0.6-0.8 mmol L respectively and about 30-40% of both metals is protein bound. The 4(X) MHz H NMR spectra of human blood plasma collected using an EDTA anticoagulant has been reported to give well-resolved signals from... [Pg.28]

A method for direct Ag determination at ppb levels in blood plasma was developed, based on GF-AAS with Zeeman effect background correction55. Selective preconcentration of several metal ions can be accomplished with poly(chlorotrifluoroethylene). Thus, after SPE of the complexes of Ag(I), Cd(II) or Cu(II) with bismuthiol II (14) at pH 2 and elution with tetrabutylammonium chloride in acetone, the eluate was directly determined by AAS72. Sub ngL-1 concentrations of Ag(I) may be preconcentrated by sorption on finely ground dithizone (12), filtration, dissolution of the dithizone in CHCI3 and end analysis by ET-AAS LOD 1 ngL-1 with no interference by humic acids, fulvic acids or soluble silica73. Ag(I) in river bottom and sea floor was preconcentrated on activated carbon containing dithizone (12), at pH 1.5 a suspension of the carbon was injected into a metal furnace AAS LOD 0.05 pg AgL-1, for 100 mL samples at SNR 359. [Pg.141]

Blood is an enormously complex system, but for our purposes we need look at only two essential components blood plasma and red blood cells, or erythrocytes. Blood plasma contains many compounds, including proteins, metal ions, and inorganic phosphates. The erythrocytes contain hemoglobin molecules, as well as the enzyme carbonic anhydrase, which catalyzes both the formation of carbonic acid (H2CO3) and its decomposition ... [Pg.663]

Platelets and white blood cells (WBC) can be labeled with In to provide agents for imaging inflammatory processes and thrombi (McAfee and Thakur 1976, Keeley and Hillis 1996, Becker and Meller 2001). A weak complex is formed between the In radiometal and 8-hydroxyquinoline (oxine). Since the hn-oxine complex is weak, the metal rapidly exchanges with transferrin in the plasma. In the absence of plasma, the complex diffuses across the cell membrane and the metal binds to intracellular sites. In humans, hn-labeledWBC will accumulate at sites of inflammation and also localize in the liver and spleen. [Pg.804]

Minoia, C., Sabbioni, E., Apostoli, P., Pietra, R.. Pozzoli, L, Gallorini, M., Nicolaou, G.. Alessio, L., and Capodaglio, E. (1990). Trace element reference values in tissues from inhabitants of the european community I. A study of 46 elements in urine, blood and serum of Italian subjects, Sci. Total Environ., 25.89-105 Olsen. A.D., and Hamlin, W.B. (1968). Serum copper and zinc by atomic absorption spectrophotometry. Atom. Absorpt. Newsl., Z, 69-71 Plantz, M.R., Fritz, J.S., Smith, F.G., and Houk, R.S. (1989). Separation of trace metal complexes for samples of high salt content by inductively coupled plasma mass spectrometry, Anal. Chem., 1,149-153... [Pg.369]

For animal fluids, amino add and protein binding appear to dominate for the trace elements. However, for Ca " and Mg citrate binding may well occur. A computer simulation exercise on blood plasma (further details in Section 22.3) suggests approximately 5% of these metal ions are in the form of dtrate complexes. The same exerdse indicates that any Fe" present would be totally bound in anionic citrate species. Interestingly the greater zinc nutritional value of human milk as opposed to bovine milk is related to zinc being present as labile citrate complexes in the former but as a tightly bound protein complex in the latter. ... [Pg.1608]


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See also in sourсe #XX -- [ Pg.2 , Pg.965 ]




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