Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ALBUMINS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1978

Effect of a short term fast on the distribution of cytoplasmic albumin messenger ribonucleic acid in rat liver. Evidence for formation of free albumin messenger ribonucleoprotein particles.

Recently, using molecular hybridization techniques with albumin [3H]cDNA, we have determined that in normally fed rats 98% of total liver polyribosomal albumin mRNA sequences are found in membrane-bound polyribosomes (Yap, S. H., Strair, R. K., and Shafritz, D. A. (1977) Proc. Natl. Acad. Sci. U. S. A. 74, 5397-5401). We now observe that a 24- to 30-h withdrawal of food leads to major changes in the amount and subcellular distribution of albumin mRNA molecules. The total amount of cytoplasmic albumin mRNA per liver and concentration of albumin mRNA per unit of membrane-bound polyribosomal RNA are decreased. However, the proportion of albumin mRNA present in the postribosomal supernatant fraction increases dramatically in a short term fast, so that it now represent 60% of total cytoplasmic albumin mRNA sequences. Most of the albumin mRNA sequences in the postribosomal supernatant fraction sediment between 30 S and 50 S. These findings suggest that albumin mRNA is probably stored in the messenger ribonucleoprotein fraction during the fasting state.

Albumins↗
PubMed1978

[The behavior of albumin in acute and chronic liver diseases. I. The behavior of albumin during the development of rat thioacetamide cirrhosis].

The behaviour of albumin during the development of chronic progressing liver damages was investigated on the model of the thioacetamide cirrhosis in Wistar-rats. Simultaneous estimations of the albumin concentrations in extractable liver protein and in the serum as well as accompanying measurements of the total protein and of the transaminases SGOT and SGPT in the serum allow a complex judgment. The albumin concentration in the liver significantly decreased after 4 and 8 weeks and reached highly normal values in fully developed cirrhosis. In each case the serum level changed in the same sense, but less expressed. The total protein in liver and serum showed an analogous course of the curve, whereas the albumin-total protein-quotient in the liver remained unchangedly low. The relative proportion of albumin in the serum did not show a diminution in every phase. The simultaneous decrease of albumin and total protein are explained as an expression of an inhibition of the synthesis due to destruction of protein-synthesizing subcellular structures. The normalisation of the serum levels and of the highly normal albumin contents despite the developed cirrhosis become understandable by the loss of efficiency of the foreign substance thioacetamide in consequence of structural and biochemical adaptation. The thioacetamide cirrhosis of the rat in the investigated phase despite the microscopically provable so-called degenerative parenchymal damages is accompained by parameters of the increased protein metabolism. The relative serum albumin content apparantly in the first place undergoes the oncotic pressure regulation and is not suited as the measure of a hepatocellular lesion. From the diagnostic point of view the reduction of the albumin concentrations seems to be of importance in the developmental phase to cirrhosis.

Alanine Transaminase↗
PubMed1982

Estrogen dramatically decreases albumin mRNA levels and albumin synthesis in Xenopus laevis liver.

The levels of albumin mRNA in Xenopus laevis liver were measured at various times after injection of estradiol using two different methods involving hybridization of cloned albumin cDNA to total liver RNA. The absolute levels of albumin mRNA fell by more than 95% during the first 4 days following estrogen treatment, then slowly returned to normal levels over the following 12 days. Albumin synthesis paralleled the albumin mRNA levels during the first 8 days after injection; but, 16 and 32 days after injection, albumin synthesis again decreased while albumin mRNA remained at normal levels. The time courses of the effects of estrogen on albumin and vitellogenin mRNA levels were different. Whereas albumin mRNA levels were minimal 4 days after estradiol injection, vitellogenin mRNA levels were maximal 8 days after injection.

Albumins↗
PubMed1996

Structure and organization of albumin molecules forming the shell of air-filled microspheres: evidence for a monolayer of albumin molecules of multiple orientations stabilizing the enclosed air.

The structure and organization of albumin molecules in the shell of air-filled microspheres formed by sonication of a 5% albumin solution have been investigated. By limited proteolysis of intact microspheres, it has been shown that every albumin molecule in the shell may be cleaved without disintegration of the microsphere structure. The microsphere shell accordingly appears to be composed of a monolayer of albumin molecules. Most of the main cleavage sites identified after N-terminal sequencing of proteolytic fragments are localized in three distinct regions common to both native and microsphere albumin molecules: the extended region of the first domain, the extended region of the second domain and the first disulphide loop of the third domain. The similarity in the localization of cleavage sites in the native and microsphere albumin molecules suggests that the formation of microspheres implies only a limited degree of conformational change of the albumin molecules. The localization of the cleavage sites in the three-dimensional structure of albumin suggests that the shell may be constituted of albumin molecules in both a native-like heart-shaped form and a more flipped-out elongated form with different orientations.

Air↗
PubMed1983

Studies on kinetics of albumin in uraemic patients on chronic haemodialysis: evidence of interstitial albumin wash-down.

Albumin-kinetic studies were performed in nine uraemic patients without oedema on chronic haemodialysis and in seven normal controls in order to determine microvascular leakiness and thereby, during steady state, lymph drainage of albumin. Transvascular escape rate of albumin [TERalb i.e. the fraction of intravascular mass (IVMalb) passing into, or returning from, the extravascular space per unit time] and the distribution ratio (DRalb) between IVMalb and total albumin mass were determined from intravenously injected radioiodinated serum albumin. Before haemodialysis, TERalb was significantly elevated (mean 9 X 6% IVMalb h-1, range 5 X 9-14) as compared to the value 15 h after haemodialysis (mean 7 X 3, range 5 X 2-11, P less than 0 X 02) and to controls (mean 5 X 9, range 4 X 3-7 X 4, P less than 0 X 01). Average DRalb (mean 0 X 54, range 0 X 44-0 X 69) was clearly elevated in patients with respect to controls (mean 0 X 44, range 0 X 42-0 X 48, P less than 0 X 01), and the extravascular mass of albumin was significantly decreased (mean 27 X 9 mumol kg-1, range 14.1 - 41.2 v. mean 35.9, range 27.1 - 43.8, P less than 0.05). We interpret the results as to indicate increased transvascular filtration of albumin in microcirculatory beds with permeable capillaries (splanchnic organs), in between the haemodialysis treatment, and filtration of protein-poor fluid in areas with 'tight' capillaries (skeletal muscle, cutis) resulting in interstitial space protein depletion here. As the patients were considered to be in steady state during the measurements, the increased TERalb indicates increased lymph flux of albumin. The interstitial space protein 'wash-down' and increased lymph drainage probably serve as oedema prevention.

Adult↗
PubMed2005

Glomerular handling of native albumin in the presence of circulating modified albumins by the normal rat kidney.

Persistent hyperglycemia, as occurring in diabetes, induces changes in circulating as well as in structural proteins. These changes involve substitution of lysine residues by glucose adducts resulting in early Amadori products that evolve into toxic and active substances, the advanced glycation end adducts. In previous studies, we demonstrated that early glycated (Amadori) albumin infused into the circulation of normal animals induces transitory alterations of glomerular filtration. Attempting to elucidate the mechanisms underlying these changes, various molecular modifications were introduced in vitro to serum albumin. Glycation, acetylation, carboxymethylation, methylation, and succinylation, involving either a few or a significant number of amino acid residues, produced heavier and more anionic albumin molecules compared with the native one. Native and each of the modified albumin molecules were injected intravenously into normal rats, followed, 30 min later, by hapten-tagged native BSA. Changes in glomerular filtration were evaluated by morphometrical analysis of gold immunolabelings. Compared with native albumin, all the modified forms of albumin induced a deeper penetration of the tracer through the glomerular basement membrane revealing alterations in glomerular permselectivity. This was more evident for severely modified albumin molecules which displayed high labelings in the urinary space and endocytic compartments of proximal tubule epithelial cells. These results indicate that modifications of serum albumin, even minimal, as those occurring in early diabetes, could immediately affect the permselectivity properties of the glomerular wall leading, with time, to severe glomerulopathies.

Animals↗
PubMed1986

First morning urinary albumin concentration is a good predictor of 24-hour urinary albumin excretion in children with type 1 (insulin-dependent) diabetes.

Twenty-four hour urinary albumin excretion was measured in 97 children with Type 1 (insulin-dependent) diabetes and found to have a geometric mean of 6 mg/day (range 1-38 mg/d). The same geometric mean of 6 mg/day (range 1-45 mg/d) was found in 120 normal children. The relationship of 24-h urinary albumin excretion to the albumin concentration (mg/l) and to the ratio of albumin: creatinine (mg:mmol) on first morning urine samples in 64 patients was highly significant (r = 0.93 and r = 0.62 respectively, p less than 0.001). In 41 patients, the relationship between 24-h urinary albumin excretion and albumin concentration upon urine samples at various times was assessed. The correlation was highest on the first morning sample (r = 0.86); 09.00 h to 13.00 h, 0.51; 13.00 h to 18.00 h, 0.68; 18.00 h to 23.00 h, 0.32. High sensitivity and moderate specificity was obtained using a first morning albumin concentration of greater than 20 mg/l to detect increased albumin excretion. These results show that the measurement of albumin concentration on the first morning urine sample can be used for a screening test for microalbuminuria in children.

Adolescent↗
PubMedDate not supplied

Diagnosing ascites: value of ascitic fluid total protein, albumin, cholesterol, their ratios, serum-ascites albumin and cholesterol gradient.

Ascitic fluid total protein, albumin, cholesterol, their ascites/serum ratios, serum-ascites albumin and cholesterol gradients were measured for their ability to differentiate cirrhotic, malignant and tuberculous ascites in 76 patients. The mean +/- s.d. ascitic fluid total protein, albumin, cholesterol, their respective ascitic fluid/serum ratios in cirrhotic ascites were lower than malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was significant for ascitic fluid/serum total protein (P < 0.05) and ascitic fluid/serum albumin (P < 0.01) only. Mean serum-ascites albumin gradient in cirrhotics was higher than in the malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was significant (P < 0.01). Mean +/- s.d. serum-ascites cholesterol gradient in cirrhotics was higher than that in malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was also significant (P < 0.01). Both serum/ascitic fluid total protein less than 0.5 and ascitic fluid cholesterol less than 55 mg/dL had 94% diagnostic accuracy for differentiating cirrhotic from malignant and tuberculous differentiating cirrhotic from malignant and tuberculous ascites. Serum ascitic fluid albumin gradient greater than 1.1 g/dL, ascitic fluid/serum albumin less than 0.65 and ascitic fluid albumin less than 2 g/dL had diagnostic accuracy of 92, 92 and 91%, respectively. Ascitic fluid total protein had diagnostic accuracy of 88%. None of the tests was able to differentiate between malignant and tuberculous ascites. Measurement of ascitic fluid cholesterol concentration is a simple method of differentiating cirrhotic from non-cirrhotic ascites.

Albumins↗
PubMedDate not supplied

The affinity of human serum albumin for [3H]-digitoxin is dependent on albumin concentration.

Binding of [3H]-digitoxin to human serum albumin and human serum was investigated in order to characterize the relationship between binding and albumin concentration. Binding was determined by equilibrium dialysis at 37 degrees, 24 hr was required to reach equilibrium. Volume shift and protein dilution were avoided by adding dextran 70 to the buffer compartment. [3H]-Digitoxin binding both to purified albumin and to normal serum was markedly pH-dependent, the bound/unbound ratio being highly significantly (P < 0.001) inversely correlated to pH in the range 6-8.5. When albumin concentration was increased within the physiological range, the ratio bound/unbound [3H]-digitoxin increased much less than expected from predictions using the law of mass action. Binding saturation experiments revealed that the equilibrium dissociation constant for [3H]-digitoxin was increased at higher albumin concentrations without any decrease in the number of binding sites per albumin molecule. In conclusion, the results strongly indicate that binding estimates in therapeutic monitoring of digitoxin in patients with elevated or reduced albumin concentration should not be based on the law of mass action but on empiric relationships between albumin concentration and binding.

Adult↗
PubMed1999

Albumin-based drug carriers: comparison between serum albumins of different species on pharmacokinetics and tumor uptake of the conjugate.

Albumin-based drug carrier systems have been developed in the field of chemotherapy to improve the passive tumor targeting properties of anti-cancer drugs. Usually, serum albumins of different species are used as carrier proteins, mostly of bovine (BSA), human (HSA) or rat (RSA) origin. The resulting albumin conjugates are often tested for anticancer activity in heterologous tumor models. No data is available whether the choice of the albumin species might influence the pharmacokinetics or the tumor uptake rates of the conjugates in vivo. Residualizingly ([111In]DTPA) radiolabeled RSA, BSA or HSA were administered to Walker-256 carcinoma-bearing rats. No significant difference was found in the absolute or the weight-adjusted tumor uptake rates of the three albumin tracers. The tumors were the major catabolic sites accumulating 14-18% of the injected dose (ID). Low hepatic uptake rates were determined for all albumins (below 100% ID). Minor differences were found for hepatic uptake in favor of the autologous RSA (5.8% ID) versus HSA (6.9%) and BSA (8.0%). These differences might have occurred during the commercial preparation or the radiolabeling of the different batches. In addition, there are structural differences between the three albumins, which might have contributed, despite high sequence homologies above 70% for RSA, HSA and BSA. These minor differences in the distribution patterns of RSA, HSA or BSA might not decisively influence the results of drug targeting experiments in rats. For further studies with albumin conjugates, HSA was chosen as drug carrier in rodent animal models when considering later human use. In rats or nude mice multiple injections of various HSA-drug conjugates were well tolerated without signs of allergy or anaphylaxis.

Animals↗
PubMed1993

Albumin-binding proteins function in the receptor-mediated binding and transcytosis of albumin across cultured endothelial cells.

The functional significance of the endothelial albumin-binding proteins (ABP) was tested on cultured bovine aortic endothelial cells (BAEC) incubated with radiolabeled albumin ([125I]Alb) alone or carrying fatty acids (oleic acid (OA) or arachidonic acid (AA)) or triiodothyronine. The [125I]Alb binding was estimated on BAEC grown on 96-well plates, and the transport was evaluated on BAEC cultured in a dual chamber system. The probe interaction with the monolayer was monitored as a function of concentration and temperature in the presence or absence of either unlabeled Alb or an anti-albumin anti-idiotypic antibody (Ab2), which was previously demonstrated to specifically recognize the ABP of endothelial cell surface. Cultured BAEC bound specifically and with high affinity [125I]Alb. The binding of fluorescein isothiocyanate (FITC)-Alb to endothelial cells was inhibited by Ab2 in immunofluorescence studies. As compared to albumin, the binding of albumin carrying either OA or AA was higher and was diminished by Ab2. Transport of [125I]Alb across BAEC grown on gelatin-coated filters increased with time, and after 60 min, approximately 30% of [125I]Alb was transported from the upper to the lower compartment; unlabeled Alb or Ab2 reduced this process by approximately 75%. Colchicine decreased transcytosis of [125I]Alb by approximately 80%, whereas chloroquine by approximately 27%. Transendothelial transport of [125I]Alb carrying fatty acids was 40% and 20% higher for OA and AA, respectively, as compared to that of defatted albumin. The results suggest the coexistence of a receptor-mediated and a receptor-independent transcytosis of albumin across cultured endothelial cells; ABP of the endothelial cell surface appear to be involved in the specific binding and transport of albumin.

Animals↗
PubMed2005

Survey of albumin purification methods for the analysis of albumin-organic toxicant adducts by liquid chromatography-electrospray ionization-tandem mass spectrometry.

HSA has been shown to react with many organic toxicants to form adducts that are useful biomarkers for exposure. Albumin isolation is an important first step for the analysis of these protein-toxicant adducts. We tested several approaches to isolate albumin from serum treated with an electrophilic organic toxicant known to form adducts with albumin, i.e., sulfur mustard agent (HD) (2,2'-dichloroethyl sulfide), in order to evaluate these techniques as purification methods. To select the most efficient isolation strategy, methods were evaluated using gel electrophoresis, total protein quantitation, and peptide-adduct identification by MS. Results suggest that the albumin-rich fractions obtained can be used to identify exposure by quantitating the albumin adducts to electrophilic organic toxicants such as HD. The HiTrap Blue HP albumin isolation system appears to display the most promising results for purifying albumin to detect HD-adducts, exhibiting high purification efficiency, satisfactory albumin recovery, promising specificity, and a higher loading capacity for serum.

Chromatography, Liquid↗
PubMed1994

Uptake and metabolism of albumin by rodent incisor enamel in vivo and postmortem: implications for control of mineralization by albumin.

The distribution of albumin throughout enamel development in the rat mandibular incisor was investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) and Western blotting employing an anti-rat albumin antibody. Intact albumin was detectable at all stages of enamel development but was most evident during late secretion/transition. Its concentration was subsequently reduced during the maturation stage. Albumin degradation products appeared during the transition/early maturation stage indicating that albumin breakdown preceded its removal. As albumin inhibits apatite crystal growth, its degradation and removal may be a necessary prerequisite for normal enamel crystal growth, perhaps reflecting a general mechanism for removal of residual endogenous matrix or adventitious crystal growth inhibitors. Additional studies revealed that the maturation stage was particularly susceptible to albumin influx postmortem. Albumin could therefore form part of the natural crystal growth control process, which, if not removed, could hamper maturation and lead to white spot hypoplasias.

Albumins↗
PubMed1980

Immune recognition of serum albumin. 11. Mouse antibodies against bovine serum albumin recognize the same antigenic sites that are recognized by rabbit antibodies.

In recent studies, we have localized and confirmed by synthetic peptides five major antigenic sites in each of bovine and human serum albumins which are recognized by rabbit antibodies against the respective protein. In order to determine whether the antigenic sites of albumin are peculiar to the protein or are dependent on the species of the immunized host, we have studied here the specificity of the antibody response in outbred mice against bovine serum albumin. By immunoadsorbent titration studies, the synthetic antigenic sites, previously localized with rabbit antisera against bovine serum albumin, were shown to bind considerable amounts of specific mouse 125I-labelled antibodies against bovine serum albumin. The amounts of mouse anti-bovine serum albumin antibodies bound by the adsorbents of the synthetic sites were comparable to the amounts of rabbit anti-bovine serum albumin antibodies that could be bound. It was concluded that recognition of the antigenic sites of serum albumin is independent of the immunized species and is inherent in their structural and conformational uniqueness.

Animals↗