scholarly journals Biosynthesis of Rat serum albumin

1971 ◽  
Vol 123 (4) ◽  
pp. 649-655 ◽  
Author(s):  
J. D. Judah ◽  
Marion R. Nicholls
Keyword(s):  
Amino Acid ◽  
Serum Albumin ◽  
Time Course ◽  
Time Lag ◽  
Rat Serum ◽  
Albumin Content ◽  
Double Label ◽  
Rat Serum Albumin

1. The labelling of intracellular and extracellular serum albumin was studied in liver slices and in whole rats by using new methods for the purification of the protein. 2. The results suggest that a polypeptide precursor is formed that is converted relatively slowly into serum albumin. 3. The effect of liver cell K+has been examined by a double-label method and it is shown that K+accelerates the rate of conversion of ‘precursor’ into albumin. The rate of transit of albumin across the cell membrane appears to be unrelated to the concentration of K+within the cell. 4. The time-course of incorporation of radioactive amino acid into albumin follows a sigmoidal mode. There is a pronounced time-lag before label starts to appear in intracellular albumin, and a further time-lag before it appears in extracellular albumin. 5. In slices the sum of intra- and extra-cellular label rises steadily from 30min after the start of labelling with a pulse of labelled leucine or valine and continues to rise for at least another 60min. This occurs whether labelling is stopped by addition of excess of carrier amino acid or with cycloheximide (100μm) or both. 6. The intracellular albumin content remains constant whether slices are maintained with low or normal intracellular K+concentrations. 7. Specific radioactivities of intracellular albumin (and fractions thereof) and of extracellular albumin were determined in vitro and in vivo. The results show that the intracellular albumin cannot be a precursor of extracellular albumin, unless a very small compartment is turning over much more rapidly than the bulk of the liver albumin or even of the microsomal albumin.

scholarly journals Comparison of kinetic study of the photochemical changes of (ZZ)-bilirubin IXα bound to human serum albumin with that bound to rat serum albumin

1985 ◽  
Vol 230 (3) ◽  
pp. 561-567 ◽  
Author(s):  
S Onishi ◽  
S Itoh ◽  
T Yamakawa ◽  
K Isobe ◽  
M Manabe ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Rate Constants ◽  
Relative Rate ◽  
Rat Serum ◽  
Relative Rate Constants ◽  
Rat Serum Albumin

It has been stated by McDonagh, Palma & Lightner [(1982) J. Am. Chem. Soc. 104, 6867-6871] that complexing of bilirubin with serum albumin has a marked species-dependent influence on bilirubin photoisomerization in vitro and in vivo. Therefore the kinetics for the quantitatively important reaction: (Formula: see text) of the photochemical interconversion between bilirubin and its photoisomers bound to human or rat serum albumin in aqueous solution, assayed by h.p.l.c., was used to elucidate the observed species-dependent difference. The relative rate constants for bilirubin bound to human serum albumin, except for k4, the rate of interconversion from (ZZ)-bilirubin into (EZ)-bilirubin, proved to be considerably larger than those for bilirubin bound to rat serum albumin. In accordance with these rate constants, the formation of photoisomers of bilirubin bound to human serum albumin, except for (EZ)-bilirubin, is very rapid and much greater than that for bilirubin bound to rat serum albumin.

Megalin/gp330 mediates uptake of albumin in renal proximal tubule

1996 ◽  
Vol 271 (4) ◽  
pp. F900-F907 ◽  
Author(s):  
S. Cui ◽  
P. J. Verroust ◽  
S. K. Moestrup ◽  
E. I. Christensen
Keyword(s):  
Bovine Serum Albumin ◽  
Ligand Binding ◽  
Serum Albumin ◽  
Proximal Tubule ◽  
Proximal Tubules ◽  
Rat Serum ◽  
Gold Particles ◽  
Receptor Associated Protein ◽  
Rat Serum Albumin

Serum albumin filtered in renal glomeruli is reabsorbed very efficiently in the proximal tubule by endocytosis. The present study was undertaken to determine whether megalin/gp330 binds and mediates endocytosis of albumin. Rat serum albumin (RSA) labeled with 125I and colloidal gold particles labeled with bovine serum albumin (BSA) were microinfused into rat surface proximal tubules in vivo, and tubular uptake was determined in the presence or absence of different substances known to interfere with ligand binding to megalin. Binding of 125I-BSA and 125I-RSA to purified megalin was also determined directly using Sepharose columns. The results revealed that the tubular uptake of 125I-labeled RSA was significantly inhibited by receptor-associated protein (RAP), which reduced the uptake by > 50% and by cold RSA. The uptake of BSA gold by the proximal tubule was very intensive. BSA gold was found in small and large endocytic vacuoles, dense apical tubules, and in lysosomes. The uptake was reduced by RAP to 17%, by EDTA to 19%, by BSA to 16%, by megalin to 35%, by cytochrome c to 49%, and, together with gentamicin, there was virtually no uptake. Megalin-Sepharose columns bound 125I-labeled BSA as well as 125I-RSA, the binding was inhibited by RAP and EDTA, and analysis of the eluate revealed the bound tracer to be albumin. In conclusion, the present study demonstrates that megalin is a mediator of albumin reabsorption in renal proximal tubules.

scholarly journals A fluorescent residualizing label for studies on protein uptake and catabolism in vivo and in vitro

1990 ◽  
Vol 267 (1) ◽  
pp. 155-162 ◽  
Author(s):  
J L Maxwell ◽  
L Terracio ◽  
T K Borg ◽  
J W Baynes ◽  
S R Thorpe
Keyword(s):  
Half Life ◽  
Normal Tissue ◽  
Degradation Products ◽  
Rat Serum ◽  
Peripheral Tissues ◽  
Protein Uptake ◽  
Kinetics Of ◽  
Rat Serum Albumin

Residualizing labels are tracers which remain in lysosomes after uptake and catabolism of the carrier protein and have been especially useful for studies on the sites of plasma protein degradation. Thus far these labels have contained radioactive reporters such as 3H or 125I. In the present paper we describe a fluorescent residualizing label, NN-dilactitol-N′-fluoresceinylethylenediamine (DLF). Modification of asialofetuin (ASF) or rat serum albumin (RSA) with DLF affected neither their normal kinetics of clearance from the rat circulation nor their normal tissue sites of uptake and degradation. After injection of DLF-ASF, fluorescent degradation products were recovered nearly quantitatively in liver and retained with a half-life of about 2 days. Fluorescent degradation products from DLF-RSA were recovered in skin and muscle, and were localized in fibroblasts by fluorescence microscopy. These results confirm previous studies with radioactive residualizing labels in which fibroblasts in peripheral tissues were identified as primary sites of albumin degradation. Fluorescent catabolites also accumulated in fibroblasts incubated with DLF-RSA in vitro, and residualized with a half-life of about 2 days. Overall, the data establish that DLF functions efficiently as a fluorescent residualizing label both in vivo and in vitro. The advantages of fluorescent, compared with radioactive, residualizing labels should make them valuable tools for studies on protein uptake and catabolism in biological systems.

Synthesis and Properties of "Hormonogene" and "Inhibitorogene" Type Oxytocin Analogs

1992 ◽  
Vol 57 (6) ◽  
pp. 1345-1351 ◽  
Author(s):  
B. C. Pal ◽  
Jiřina Slaninová ◽  
Tomislav Barth ◽  
Jerzy Trojnar ◽  
Michal Lebl
Keyword(s):  
Amino Acid ◽  
Inhibitory Action ◽  
Time Course ◽  
Solid Phase ◽  
Prolonged Time ◽  
Prolonged Effect ◽  
In Vivo Tests

Nα-Glycyl, diglycyl and triglycyl [2-D and [2-L-p-ethylphenylalanine]oxytocin analogs were synthesized by the solid phase technology utilizing racemic p-ethylphenylalanine. Analogs containing this amino acid of D-configuration were shown to be weak uterotonic antagonists both in vitro and in vivo tests; the compound containing triglycyl residue in position 1 was shown to have prolonged time course of inhibitory action. Analogs containing the L-amino acid were shown to be inhibitors of uterotonic activity of oxytocin in vitro, but uterotonic agonists with prolonged effect in vivo.

Sarcolemmal disruption in reloaded atrophic skeletal muscle

1995 ◽  
Vol 79 (2) ◽  
pp. 607-614 ◽  
Author(s):  
C. E. Kasper
Keyword(s):  
Skeletal Muscle ◽  
Serum Albumin ◽  
Time Course ◽  
Intracellular Staining ◽  
Rat Serum ◽  
Cross Sectional ◽  
Membrane Rupture ◽  
Female Wistar Rats ◽  
Hind Limb Unloading ◽  
Rat Serum Albumin

The purpose of this study was to determine whether reloading of atrophied skeletal muscle after 28 days of hind-limb unloading (HU) would produce significant sarcolemmal membrane disruption before frank necrosis. Soleus and plantaris muscles were atrophied by HU. Adult female Wistar rats (N = 13) were killed at 28 days of unloading and 4 and 7 days of reloading after HU. Rat serum albumin was used as a marker for muscle fiber disruption. Dark intracellular staining with horseradish peroxidase-conjugated anti-rat serum albumin antibody was interpreted as evidence of membrane rupture. There was a significantly different time course of disruption between plantaris and soleus muscles, with a negative correlation between cell size and occurrence of disruption. Fourteen percent of plantaris fibers were wounded after HU, peaking at day 4 of reloading (20% of cross-sectional area). Soleus demonstrated disruption only on reloading peaking in severity at day 7 (14% of fibers). It was demonstrated that sarcolemmal disruption due to atrophy and reloading does not always progress to necrosis and degeneration by the 7th day of recovery.

scholarly journals Experimental Approaches and Computational Modeling of Rat Serum Albumin and Its Interaction with Piperine

2019 ◽  
Vol 20 (12) ◽  
pp. 2856 ◽  
Author(s):  
Gabriel Zazeri ◽  
Ana Paula Ribeiro Povinelli ◽  
Marcelo de Freitas Lima ◽  
Marinônio Lopes Cornélio
Keyword(s):  
Serum Albumin ◽  
Well Being ◽  
Piper Nigrum ◽  
Computational Techniques ◽  
Spectroscopic Techniques ◽  
Rat Serum ◽  
Therapeutic Trials ◽  
Experimental Approaches ◽  
Rat Serum Albumin

The bioactive piperine (1-piperoyl piperidine) compound found in some pepper species (Piper nigrum linn and Piper sarmentosum Roxb) has been shown to have therapeutic properties and to be useful for well-being. The tests used to validate these properties were performed in vitro or with small rats. However, in all these assays, the molecular approach was absent. Although the first therapeutic trials relied on the use of rats, no proposal was mentioned either experimentally or computationally at the molecular level regarding the interaction between piperine and rat serum albumin (RSA). In the present study, several spectroscopic techniques were employed to characterize rat serum albumin and, aided by computational techniques, the protein modeling was proposed. From the spectroscopic results, it was possible to estimate the binding constant (3.9 × 104 M−1 at 288 K) using the Stern–Volmer model and the number of ligands (three) associated with the protein applying interaction density function model. The Gibbs free energy, an important thermodynamic parameter, was determined (−25 kJ/mol), indicating that the interaction was spontaneous. This important set of experimental results served to parameterize the computational simulations. The results of molecular docking and molecular dynamics matched appropriately made it possible to have detailed microenvironments of RSA accessed by piperine.

INCREASE OF SERUM FREE THYROXINE FOLLOWING THE ADMINISTRATION OF THIOCYANATE AND OTHER ANIONS IN VIVO AND IN VITRO

1974 ◽  
Vol 75 (4) ◽  
pp. 707-716 ◽  
Author(s):  
N. Michajlovskij ◽  
P. Langer
Keyword(s):  
Time Course ◽  
Linear Increase ◽  
Free Thyroxine ◽  
Peroral Administration ◽  
Rat Serum ◽  
Serum Free ◽  
Serum Free Thyroxine

ABSTRACT Following the addition of thiocyanate (SCN−) to human and rat serum of 80 mg SCN−/ 100 ml (initial concentration before dialysis) a marked increase in serum free thyroxine (FT4) was found. The addition of equivalent doses of other antihyroid anions or permanganate showed a similar increase of FT4 in the order: BF4− < CIO4− = SCN− < MnO4−. The increase in the rat serum was greater than that in human serum. After peroral administration of these anions to the rats in amounts equal to 30 mg SCN−/rat the increase of FT4 was still higher. The addition of increased doses of SCN− to the human and rat sera (5-80 and up to 1600 mg SCN−/100 ml) caused a linear increase of FT4. Similarly, after the administration of various doses of SCN− to rats (5-30 mg SCN−/rat) a linear dose-response of the FT4 level in serum was observed. The time-course of the increase of % FT4 and absolute FT4 (AFT4) level after a single administration of SCN− to rats coincided with the increase of the serum SCN− level. However, after the disappearance of SCN− from the serum the % FT4 returned to the initial value, while the AFT4 was decreased. The effect of these anions probably consists in the competitive displacement of thyroxine from serum thyroxine-binding proteins. These and previous results suggested that thiocynate influences the plasma protein-thyroxine equilibrium and the possible role of an increased free thyroxine level on the action of thyroxine on various tissues and the hypothalamo-pituitary-thyroid feed-back is discussed.

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