Blood substitutes phosphate

A large number of xenobiotics, such as esters, amides, or substituted phosphates that include ester-type bonds, are susceptible to hydrolysis. Hydrolytic reactions are the only phase I reactions that do not utilize energy. Numerous hydrolases are found in blood plasma, liver, intestinal muscosa, kidney, muscle, and nervous tissue. Hydrolases are present in both soluble and microsomal fractions. The general reactions are shown in Figure 10.10A. 

Self-propelling aerosols of antiallergic, antibiotic, antitussive, or antianginal activities have been prepared using a fluorinated surfactant as the dispersant in Freon 114 and Freon 12 [203]. As an example, epinephrine bitartrate has been dispersed with perfluoro-n-octyl- -ethylsulfonamidoethyl phosphate. The use of fluorinated surfactants in intravascular oxygen carriers and blood substitutes is discussed in Chapter 10. 

F14. Fujii, H., Kanno, H., and Miwa, S., Expression and enzymatic characterization of the glucose phosphate isomerase variants with diverse single amino acid substitutions. Blood 88 (Suppl. 1), 306a (1996). 

V12. Vives Corrons, J. L. 1., Rovira, A., Pujades, A., Vulliamy, T., and Luzzatto, L., Molecular heterogeneity of glucose-6-phosphate dehydrogenase (G6PD) in Spain and identification of two new base substitutions in the G6PD gene, Blood 84 (Suppl. 1), 551a (1994). 

Peripheral to the Gal-GlcNAc sequences of glycoproteins, there can occur an array of blood-group-related glycosylations, anionic substitutions (sialy-lation, 0-sulfation, and 0-phosphorylation), or both. Chains of the high-mannose type may also bear phosphate groups. Table VI reviews the pat-... 

The polypeptide parathormone is released from the parathyroid glands when plasma Ca + level falls. It stimulates osteoclasts to increase bone resorption in the kidneys, it promotes calcium reabsorption, while phosphate excretion is enhanced. As blood phosphate concentration diminishes, the tendency of calcium to precipitate as bone mineral decreases. By stimulating the formation of vit D hormone, parathormone has an indirect effect on the enteral uptake of Ca + and phosphate. In parathormone deficiency, vitamin D can be used as a substitute that unlike parathormone, is effective orally. 

Citric acid is used in soft drinks, candies, wines, desserts, jellies, jams, as an antioxidant in frozen fruits and vegetables, and as an emulsifier in cheese. As the most versatile food acidulant, citric acid accounts for about 70 percent of the total food acidulant market. It provides effervescence by combining the citric acid with a biocarbonate/carbonate source to form carbon dioxide. Citric acid and its salts are also used in blood anticoagulants to chelate calcium, block blood clotting, and buffer the blood. Citric acid is contained in various cosmetic products such as hair shampoos, rinses, lotions, creams, and toothpastes. More recently, citric acid has been used for metal cleaning, substituted for phosphate in detergents, for secondary oil recovery, and as a buffer/absorber in stack gas desulfurization. The use of sodium citrate in heavy-duty liquid laundry detergent formulations has resulted in a rapid increase in the use of citric acid. 

The discovery of the statin mevalonic acid synthesis inhibitors focused new attention on control of blood lipid levels as a measure to stave off heart disease. A number of compounds have been found that treat elevated lipid levels by other diverse mechanisms. The phosphonic acid derivative ibrolipim (9) is believed to lower those levels by accelerating fatty acid oxidation. The phosphoms-containing starting material 7 can in principle be obtained by the Arbuzov reaction of a protected from of p-bromomethylbenzoic acid (6) with triethyl phosphate. Removal of the protecting group and conversion of the acid to an acyl chloride then affords 7. Condensation of this intermediate with substituted aniline 8 leads to the hypolipidemic agent (9). ... 

The presence of complexing ligands in the diet or drinking water may dangerously affect the bio-availability of a metal in the blood or tissues one example of this is the use of powerful chelators, such as the anions of nitrilotriacetic acid or ethylenediaminetetraacetic acid (EDTA) as substitutes for phosphate in washing powders. It has been calculated that in some parts of the world the concentration of EDTA in ground or river water may be as high as 100 imol dm . ... 

In a study of the effects of organic mercurials on the cation permeability of human red blood cells, Knauf and Rothstein (1971) found that the rate of uptake of PCMBS was diminished by 50% in cells exposed to SITS (4-acetamido-4 -isothiocyano-stilbene 2,2 -disulfonic acid), so that the total uptake could be divided into roughly equal SITS-sensitive and SITS-insensitive components. If the chloride in the bathing solution was replaced with either sulfate or phosphate, the SITS-sensitive component of PCMBS uptake was virtually unchanged whereas the SITS-insensitive component was substantially reduced. One interpretation of these results is that PCMBS enters by two routes, one the anion transporter that serves as a route for anionic complexes, and the other the lipid layer that permits the permeation of a neutral Cl complex of PCMBS, the latter perhaps being less abundant in the anion substituted media. Alternatively, a cationic form of the mercurial could permeate via some other membrane protein. 

---