Serum species differences

At moderately acidic pH values, the short chain fatty acid, caprylic acid, is an effective protein precipitant. It has found an application in immunoglobulin purification as conditions have been developed that result in the precipitation of the majority of non-immunoglobin proteins in the serum leaving the antibodies in solution. The concentration of caprylic acid required differs for the serum of different species as shown in Table 1 (see Note 12). 

Costa, L.G., Richter, R.J., Murphy, S.D., Omenn, G.S., Moml-sky, A.G., Furlong, C.E. (1987). Species differences in serum paraoxonase correlate with sensitivity to paraoxon toxicity. In Toxicology of Pesticides Experimental Clinical and Regulatory Perspectives (L.G. Costa, C.L. Galli, S.D. Murphy, eds), pp. 263-6. Springer-Verlag, Heidelberg. 

In the early 1950s, Karush reported on the differential binding of the enantiomers of an anionic azo-dye, first to bovine (14) and then human (15) serum albumins. Although not of direct clinical significance, the work of Karush created an avirareness of the potential of enantioselectivity in binding to plasma proteins and marks the first reports of species differ-... 

An interesting species difference might be pointed out. The above HMG-CoA reductase inhibitors inhibit HMG-CoA reductase from a variety of animals, and reduce serum cholesterol in humans, rabbits and dogs, but do not reduce serum chr lesterol in rats and mice (Sakono et ai, 1996). 

Definitive conclusions regarding human hepatotoxiciy are hampered by limitations in study design of available studies, such as exposure misclassificafion, lack of controls, lack of correction for common confounding variables (e.g., age and alcohol consumption), and natural partitioning of PCBs to serum lipids. The lack of unequivocal evidence in humans that is seen in laboratory animals may result from many factors, including species differences in susceptibility or sensitivity to PCBs, and dissimilarities in exposure levels, durations, and mixture compositions. 

Magnesium Concentration. Another factor which may influence secretion is magnesium in the medium. Foldes (16) has recently emphasized the fact that Mg + (as well as Ca +) varies in the serum of different species and that many "balanced electrolyte solutions such as Krebs Solution, do not have the correct amounts of magnesium. Douglas and Rubin (9) showed many years ago that a relatively low concentration of Mg2+ (2 mM) prevented adrenal... 

Kosa, T, T. Maruyama, and M. Otagiri. 1997. Species differences of serum albumins I. Drug binding sites. Pharmaceutical Research 14 1607-1612. 

Blanchard, J.R.T. and Tasker, R.A.R., High performance hquid chromatographic assay for domoic acid in serum of different species. J. Chromatogr, 526, 546, 1990. 

Different species may have better properties for acting as capture reagents and also show varying specificities. This can be assessed in chessboard titrations and is relevant because we require results on the detection and titration of cattle sera so that the competitive phase relies on the interruption of a pretitrated antibody as close to the reaction of cattle serum with antigen as possible. Rabbit or guinea pig serum may differ in their specificities as compared to cattle sera. 

There is still another series of vital reactions that remain as yet undiscussed. Each time that it was desired to prepare an antibody, a species different from that which furnishes the immunogen substance was taken. Now, it has been found in special cases that not only the same species can react but also the same individual. Thus the blood corpuscles of goat A, injected into a goat B, cause the formation of isolysins in the serum of B, capable of dissolving the corpuscles of the goat A and of a certain number of other goats, but not of aU goats. 

Since the rodent effects of PPs ate mediated via PPARa and humans appear to be non-responsive to these adverse effects, species differences in PPARa expression levels provide a plausible explanation for the lack of hitman response. However, humans do respond to PPs by altering etqtression of enzymes that regulate serum cholesterol and lipid homeostasis. " In addition, human liver does contain a functional PPARa although the expression of PPARa in humans is around 10-fold lower when compared with responsive species such as rat and mouse."" "" In total, these data support a quantitative hypothesis whereby PPARa expression in humans is sufficient to mediate the beneficial effects of hypolipidaemic dmgs via regulation of genes for enzymes and lipid transporters. 

This information was used to cmistruct a PBPK/PD model in the adult male rat (MirfazaeUan et al. 2006). Godin et al. (2006) examined species differences between rat and human liver microsomal carboxylesterases. A significant species difference was noted in the in vitro biotransformation of deltamethrin, due in part to differences in the rate of hydrolysis by human liver microsomes. Godin et al. (2007) identified the rat and human CYP450 isoforms, and rat serum esterases that metabolize deltamethrin and esfenvalerate. Differences in the rates of hepatic oxidative metabolism were related to expression levels (abundance) of the individual P450 isoforms rather than their specific activity. 

Hobby et al. (76) and McClean (103) observed that normal sera of several species inhibit the in vitro action of hyaluronidase from different sources. This nonspecific, heat-labile serum inhibitor differs from the inhibitor present in anti-hyaluronidase immune serum. The latter is a true antibody (104). The nonspecific serum inhibitor is increased in a... 

Evidence that PONl plays a role in modulating the in vivo toxicity of OPs has emerged over the past 20 years, although it had already been noted that species differences in PONl activity correlated with suscepHbility to OP toxicity (Costa et al., 1987 Furlong et al., 2000). A previous study by Main (1956) showed that intravenous administration of partially purified PONl from rabbit serum would protect rats from the toxicity of paraoxon therefore, several initial studies followed a similar approach. Administration (by the intravenous route) of purified rabbit PONl to rats protected the animals from acetylcholinesterase (AChE) inhibition by chlorpyrifos oxon and paraoxon (Costa et al., 1990). Further studies in mice provided evidence that intravenous administration... 

Soltes, L., Sebille, B. (1997). Reversible binding interactions between the tryptophan enantiomers and albumins of different animal species as determined by novel high performance liquid chromatographic methods an attempt to localize the d- and L-tryptophan binding sites on the human serum albumin polypeptide chain by using protein fragments. Chirality 9, 373-379. 

Derrick studied the interaction of L-tryptophan and ibuprofen with human serum albumin (HSA),74 which is an abundant transport blood protein capable of binding efficiently several species.75 They acquired 1H NMR spectra of L-Tryptophan-HSA system for different ligand protein molar ratios, that is 3 1, 5 1, 7 1 and 10 1. The aromatic resonances of L-Tryptophan are difficult to be observed due to the overlap with HSA signals, even at 10 1 molar ratio, so that the spectral subtraction was performed. D values of L-Tryptophan were calculated by integration of the subtracted spectra and were in good agreement with those predicted by computer simulations. In the case of ibuprofen, only for 140 1 molar ratio, the resonances of ibuprofen are clearly visible also in this case, the... 

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