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Abstract

The acute-phase response alters the composition of carrier proteins in plasma, which may affect the blood deposition and transport of biomediators and drugs. The effect of the acute-phase response on the ligand binding ability of plasma was studied in leukemic children with and without systemic inflammation (sepsis and septic shock). To target different transport proteins, differentially charged fluorescent dyes were used: anionic ANS (8-anilinonaphthalene-1-sulfonate), uncharged Nile red, and cationic Quinaldine red. Human serum albumin was a principal carrier for ANS and competed for Nile red binding with lipoproteins. The synchro-scan fluorescence spectra of Nile red in plasma distinguished two species of the dye bound to serum albumin and to low-density and/or very low-density lipoproteins. The binding of Quinaldine red did not correlate with albumin and lipoprotein levels, and was probably determined by alpha(1)-acid glycoprotein. Compared with the control group, leukemia increased Quinaldine red binding by 65% and did not significantly affect the binding of other probes. Sepsis and septic shock did not change the binding of Quinaldine red, but progressively decreased ANS binding, finally by about 33%, and shifted Nile red distribution from serum albumin toward lipoproteins. These changes reflected a modified composition of the three principal transport proteins in plasma in the acute-phase response. Simple and rapid fluorescent tests developed in this study can be used to evaluate the acute-phase response and to optimize drug administration protocols in clinical practice.

Estimation of the binding ability of main transport proteins of blood plasma with liver cirrhosis by the fluorescent probe method

“…Only scattered reports have appeared on the simultaneous use of fluorescent probes [15,16] and not one on the simultaneous use of them to estimate the binding ability of plasma transport proteins with LC for diagnosis.…”

“…For the NR probe, fluorescence spectra were recorded by synchronous scanning over excitation and emission wavelengths with a constant difference between them of ∆λ = 15 nm. The ratio of fluorescence intensities of LPbound NR at λ max = 554 nm and HSA-bound NR at λ max = 592 nm, I 554 /I 592 , was determined and reflects the distribution of NR between these two fractions in blood plasma [16] (Fig. 1).…”

“…HSA is the main transport protein that binds anionic fluorescent probe ANS in blood plasma [16,19]. The fluorescence intensity depends on both the HSA concentration in blood plasma and on its loading by metabolites and xenobiotics.…”

“…Neutral probe NR distributes in blood plasma between LP and HSA [16,20,21]. Fluorescence spectra of NR probe were obtained using the synchronous scanning method, which is widely used at present for fluorescent analysis of multi-component systems [16,22].…”

“…Fluorescence spectra of NR probe were obtained using the synchronous scanning method, which is widely used at present for fluorescent analysis of multi-component systems [16,22]. The method is based on the known fact that absorption spectra maxima and fluorescence spectra of fluorophores are related and is described by the theory of the Stokes shift.…”