Blood plasma species

Dextran. This polysaccharide is produced from sucrose by certain species of l euconostoc (70). Dextran [9004-54-0] was the first commercial microbial polysaccharide. It was used as a blood plasma extender in the U.S. Army during the late 1940s and early 1950s. This program was discontinued in 1955. 

As the superoxide radical is a precursor of the other reactive oxygen species and interacts with blood plasma components under physiological and pathological conditions as well, systems related to its generation are biologically relevant. It should be noted, however, that with respect to the initiation of lipid peroxidation as one of the main causes of oxidative cell damage, its own reactivity is very weak and that only in protonized form is its toxicity comparable to that of lipid peroxyl radicals [18]. 

The equilibrium constants given above for the hydrolysis and protolysis reactions of cis- and trans-DDP can be employed to construct distribution diagrams of various species as a function of the pH. In human blood plasma ([Cl-] = 0.1 M) the dichloro species predominates at about pH 7.4 for both cis- and frans-DDP (Figure 4). By contrast, in intracellular conditions ([Cl ]ambient = 0.004 M) the hydrolysis products dominate, but the distribution behavior of the two isomers is quite... 

In blood plasma, the chloride ion concentration is sufficiently large (about 100 mAf) to prevent cis-Pt hydrolysis, and the neutral platinum species most likely crosses the cell membrane. Inside the cell the chloride ion concentration is much lower (about 4mM), which allows for hydrolysis (35, 37). Because water is a far better leaving group than chloride or hydroxide (38, 39), the aqua species are most likely the reactive form of cis-Pt in vivo. Thus hydrolysis is the rate-limiting step in the reaction of cis-Pt with biomolecules such as proteins, RNA, and DNA (40). 

From potentiometric and spectroscopic studies it is concluded that the main species at neutral pH is a 1 1 tridentate chelate (11) with a log stability constant of ca. — 4. The claim55 that the stability of this species is comparable to that of the Cu(albumin) complex is rather surprising, since for this to occur the involvement of a histidine in the third amino add position is normally required, and furthermore others have concluded that in blood plasma at least the tripeptide is unlikely to compete against other ligands for the available Cu11.56,57 To illustrate the point that such conclusions from blood plasma simulations are only applicable to that medium, Pickart and Thaler58 have shown that in a cell culture medium the tripeptide considerably enhanced Cu uptake into cells and that this was not affected by a 300-fold molar excess of amino adds, including histidine. 

Takatera and Watanabe [41] used this technique for the speciation of iodide ion, I-, and five iodo amino acids (monoiodotyrosine (MIT), diiodotyrosine (DIT), 3,3,5-triiodothyromine (T3), 3,3,5 -triiodothyromine (rT3), and thyroxine (T4)) which are all found in thyroid hormones. The speciation of these compounds in clinical samples such as blood plasma and urine may assist in the identification of thyroid diseases. The RPLC-ICP-MS system was able to detect all of the I-containing compounds with no interferences. Detection limits were in the range 35-130 pg for the six compounds using a 50% methanol eluent. Detection limits were better for species eluted at a shorter retention time since the peak shapes were sharper. The detection limits calculated were an order of magnitude lower than for methods where UV absorbance detection was used. 

Fig. 11 Great Lakes food web, with approximate PCB concentrations. Note that PCB concentrations vary significantly among species in different locations, and among individuals of the same species. Concentrations in humans are estimated from the blood plasma concentrations in humans that eat Lake Michigan fish [314] and the distribution of PCBs in the body of rats [35]. See text for additional references...

The mineral concentrations in the blood plasma of the primitive cyclostomes (hagfish and lampreys) are close to those of the surrounding sea water (Robertson, 1954 McFarland and Munz, 1958 Bellamy and Chester Jones, 1961). More evolutionarily advanced species maintain relatively lower internal concentrations, presumably because the tissues function best under... 

Values of TAC found for blood plasma or serum of some animal species are given in Table 9 and Fig. 8. Comparison of values for several species of mammals... 

TAC of urine and seminal plasma is comparable to, or even higher than, that of blood plasma (Table 10). TAC of seminal plasma was significantly lower in va-sectomized men compared with that of normozoospermic donors. This indicates that the epididymis contributes to the antioxidant capacity of seminal plasma and possesses region-specific antioxidant activity, which may potentially protect spermatozoa from oxidative attack during storage at this site (P21). TAC of seminal plasma of several avian species was reported to show large interspecies differences (from 0.62 mM for chicken up to 13.15 mM for turkey). TAC showed a significant correlation with the protein concentration of seminal plasma (S30). 

Is TAC, representing mainly the second line of antioxidant defense (interception of reaction of uncontrolled oxidation), as important as specific antioxidant mechanisms of the first line of antioxidant defense (preventing the formation of reactive oxygen species) If so, one should perhaps expect high TAC values of biological fluids of crucial importance such as seminal plasma. Instead, TAC of blood plasma and seminal plasma is comparable with that of urine and much lower than that of feces (Tables 8 and 10). 

Table 2 lists the mole fraction of six cis- and trans-(NH3)2Ptu species at pH 7.4 and at the ambient chloride concentrations of the blood plasma (104 mM) and of the cell nucleus (4 him). Chloro complexes dominate in the plasma and hydroxo complexes in the nucleus. 

However, because of the slowness of Ptn conversions, the various (NH3)2Ptn species may not be at equilibrium with ambient 4 mM chloride in the cell nucleus. The (NH3)2Ptn species may be more nearly in equilibrium with the ambient 104 mM chloride of the blood plasma, where the administered drug has circulated. For conversion from administered dichloro to diaqua complexes in acidic solutions the successive half lives at 45 °C are 1.0 and 0.8 h for cis and 0.18 and 48 h for trans isomers [3], These times agree with the well-documented trans-activating order Cl > NH3 > H20. Therefore, we have performed a similar analysis of the reaction rate with inosine N(7) assuming that the (NH3)2Ptn species are in equilibrium with the blood plasma and the results appear under the columns labeled 104 mu in Table 3. At 104 mM CP, the total reactivities of all cA-species are 1/3, and those of all trans-species 2/3 those at 4 mM. 

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