THE INCORPORATION OF TRYPTOPHAN ANALOGUES INTO RAT PLASMA PROTEINS

1962 ◽  
Vol 40 (2) ◽  
pp. 153-157 ◽  
Author(s):  
Anita Berecz ◽  
C. Godin
Keyword(s):  
Plasma Proteins ◽  
Rat Plasma ◽  
Tryptophan Analogues

When 7-azatryptophan and 5-methyltryptophan are fed to protein-depleted rats, the animals lose weight more rapidly than control rats. Protein-depleted rats fed a diet containing tryptophan gain weight. 7-Azatryptophan is incorporated in vivo into rat plasma proteins, whereas 5-methyltryptophan is not incorporated.

THE INCORPORATION OF TRYPTOPHAN ANALOGUES INTO RAT PLASMA PROTEINS

1962 ◽  
Vol 40 (1) ◽  
pp. 153-157 ◽  
Author(s):  
Anita Berecz ◽  
C. Godin
Keyword(s):  
Plasma Proteins ◽  
Rat Plasma ◽  
Tryptophan Analogues

When 7-azatryptophan and 5-methyltryptophan are fed to protein-depleted rats, the animals lose weight more rapidly than control rats. Protein-depleted rats fed a diet containing tryptophan gain weight. 7-Azatryptophan is incorporated in vivo into rat plasma proteins, whereas 5-methyltryptophan is not incorporated.

scholarly journals FLUORESCEIN-CONJUGATED BOVINE ALBUMIN

1953 ◽  
Vol 36 (4) ◽  
pp. 489-506 ◽  
Author(s):  
Alfred A. Schiller ◽  
Richard W. Schayer ◽  
E. L. Hess
Keyword(s):  
Plasma Proteins ◽  
Isotope Labeling ◽  
Rat Plasma ◽  
Sodium Fluorescein ◽  
Rat Tissues ◽  
Renal Tubules ◽  
Bovine Albumin ◽  
Degree Burn ◽  
Collecting Tubules

Fluorescein-bovine albumin conjugates have been prepared and found not to differ appreciably in size, shape, and homogeneity from the precursor, bovine serum albumin. Fluorescein has also been conjugated to rat plasma proteins. Their disappearance rates from the circulation of rats correspond with those obtained from the use of isotope labeling. Their sites of localization in rat tissues were shown to be in the cytoplasm but not in the nuclei of Kupffer cells, fixed macrophages, granulocytes, and proximal renal tubules. Adsorption to endothelium was a characteristic finding. Extracellular localizations were predominantly in the lumina of blood vessels and proximal renal tubules (but never in the lumina of collecting tubules), and the interstitial fluid of skeletal and cardiac muscle (but not that of glandular organs such as the adrenals, liver, and spleen). BAC absorption from the skin of rabbits requires days whereas sodium fluorescein absorption is measured in hours, attesting to the persistence of the colloidal state of BAC in vivo. Fluorescein conjugates have been used to visualize the transcapillary passage of circulating proteins in the mesenteric circulation of frogs and rats by direct microscopic observation and found to diffuse slowly in the manner predicted for plasma proteins. The normal cutaneous vessels of the rat are impermeable in the gross to the labeled proteins; second degree burn promptly increases the permeability of these vessels rendering the presence of the label detectable in the gross in the skin. The process of labeling does not render guinea pig albumin antigenic, although slight antigenicity results from labeling whole plasma protein. It is believed that sufficient biological evidence is presented to support the conclusion that fluorescein-conjugated plasma proteins, particularly albumin, behave in vivo like their native precursors.

EFFECT OF DIALYSIS AND OXIDATION ON PLASMA PARATHYROID HORMONE ACTIVITY

1961 ◽  
Vol 37 (1) ◽  
pp. 148-152 ◽  
Author(s):  
Leo E. Reichert ◽  
Maurice V. L'Heureux
Keyword(s):  
Parathyroid Hormone ◽  
Parathyroid Gland ◽  
Plasma Proteins ◽  
Rat Plasma ◽  
Active Principle ◽  
Peroxide Oxidation ◽  
Hormone Activity ◽  
Oxidative Inactivation ◽  
Gland Extract

ABSTRACT Comparative studies are reported on the effect of dialysis and peroxide oxidation upon the calcium mobilizing activity of a potent parathyroid gland preparation, Injection Parathyroid, U. S. P. (Lilly), when in aqueous solution and when incubated with freshly collected rat plasma prior to treatment. It was found that although dialysis and oxidation markedly decreased the potency of the parathyroid gland extract employed, prior incubation with rat plasma prevented this effect from occurring. It is suggested that a binding of the active principle of the extract to plasma proteins could account for the phenomena observed. The suggestion that oxidative inactivation of parathyroid hormone is of significance, in vivo, would not seem to be in accord with the observations recorded here.

Purification of the Antihemophilic Factor by Gel Filtration on Agarose

1969 ◽  
Vol 22 (03) ◽  
pp. 577-583 ◽  
Author(s):  
M.M.P Paulssen ◽  
A.C.M.G.B Wouterlood ◽  
H.L.M.A Scheffers
Keyword(s):  
Factor Viii ◽  
Plasma Proteins ◽  
Large Scale ◽  
Gel Filtration ◽  
Large Scale Preparation ◽  
Scale Preparation ◽  
Antihemophilic Factor

SummaryFactor VIII can be isolated from plasma proteins, including fibrinogen by chromatography on agarose. The best results were obtained with Sepharose 6B. Large scale preparation is also possible when cryoprecipitate is separated by chromatography. In most fractions containing factor VIII a turbidity is observed which may be due to the presence of chylomicrons.The purified factor VIII was active in vivo as well as in vitro.

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

Accumulation of Human Apolipoprotein-E in Rat Plasma After in vivo Intramuscular Injection of Naked DNA

1994 ◽  
Vol 200 (1) ◽  
pp. 298-305 ◽  
Author(s):  
V.M. Fazio ◽  
S. Fazio ◽  
M. Rinaldi ◽  
M.V. Catani ◽  
S. Zotti ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Intramuscular Injection ◽  
Rat Plasma ◽  
Human Apolipoprotein ◽  
Naked Dna

scholarly journals Unraveling the In Vivo Protein Corona

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 132
Author(s):  
Johanna Simon ◽  
Gabor Kuhn ◽  
Michael Fichter ◽  
Stephan Gehring ◽  
Katharina Landfester ◽  
...  
Keyword(s):  
Plasma Proteins ◽  
Ex Vivo ◽  
Protein Corona ◽  
Blood Proteins ◽  
Therapeutic Application ◽  
Complex Situation ◽  
Ex Vivo Approach ◽  
In Vivo Administration

Understanding the behavior of nanoparticles upon contact with a physiological environment is of urgent need in order to improve their properties for a successful therapeutic application. Most commonly, the interaction of nanoparticles with plasma proteins are studied under in vitro conditions. However, this has been shown to not reflect the complex situation after in vivo administration. Therefore, here we focused on the investigation of magnetic nanoparticles with blood proteins under in vivo conditions. Importantly, we observed a radically different proteome in vivo in comparison to the in vitro situation underlining the significance of in vivo protein corona studies. Next to this, we found that the in vivo corona profile does not significantly change over time. To mimic the in vivo situation, we established an approach, which we termed “ex vivo” as it uses whole blood freshly prepared from an animal. Overall, we present a comprehensive analysis focusing on the interaction between nanoparticles and blood proteins under in vivo conditions and how to mimic this situation with our ex vivo approach. This knowledge is needed to characterize the true biological identity of nanoparticles.

scholarly journals A synthetic glucagon-like peptide-1 analog with improved plasma stability

1998 ◽  
Vol 159 (1) ◽  
pp. 93-102 ◽  
Author(s):  
U Ritzel ◽  
U Leonhardt ◽  
M Ottleben ◽  
A Ruhmann ◽  
K Eckart ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plasma Insulin ◽  
Rat Plasma ◽  
Plasma Stability ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Glucagon-like peptide-1 (GLP-1) is the most potent endogenous insulin-stimulating hormone. In the present study the plasma stability and biological activity of a GLP-1 analog, [Ser]GLP-1(7-36)amide, in which the second N-terminal amino acid alanine was replaced by serine, was evaluated in vitro and in vivo. Incubation of GLP-1 with human or rat plasma resulted in degradation of native GLP-1(7-36)amide to GLP-1(9-36)amide, while [Ser]GLP-1(7-36)amide was not significantly degraded by plasma enzymes. Using glucose-responsive HIT-T15 cells, [Ser]GLP-1(7-36)amide showed strong insulinotropic activity, which was inhibited by the specific GLP-1 receptor antagonist exendin-4(9-39)amide. Simultaneous i.v. injection of [Ser]GLP-1(7-36)amide and glucose in rats induced a twofold higher increase in plasma insulin levels than unmodified GLP-1(7-36)amide with glucose and a fivefold higher increase than glucose alone. [Ser]GLP-1(7-36)amide induced a 1.5-fold higher increase in plasma insulin than GLP-1(7-36)amide when given 1 h before i.v. application of glucose. The insulinotropic effect of [Ser]GLP-1(7-36)amide was suppressed by i.v. application of exendin-4(9-39)amide. The present data demonstrate that replacement of the second N-terminal amino acid alanine by serine improves the plasma stability of GLP-1(7-36)amide. The insulinotropic action in vitro and in vivo was not impaired significantly by this modification.

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