Distribution of radioactive silver in the subcellular fractions of various tissues of the rat and its binding to low molecular weight proteins

1983 ◽  
Vol 61 (11) ◽  
pp. 1391-1395 ◽  
Author(s):  
Yousef Matuk
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Filtration ◽  
Total Radioactivity ◽  
Subcellular Fractions ◽  
Low Molecular Weight ◽  
Electron Microscopic ◽  
Molecular Weight Peak

In view of the electron microscopic evidence that silver does not penetrate cellular barriers, the distribution of radioactive silver in rat blood and subcellular fractions of liver, kidneys, spleen, and forebrain was studied. It was found that 24 h after a single intraperitoneal injection high levels of radioactivity were reached which decreased at different rates in the various tissues studied. In plasma, liver, and kidneys there was an initial rapid loss of radioactivity which was followed by a slower rate of loss. In the blood, forebrain, and spleen the loss of radioactivity was linear and somewhat slower than in the other three tissues. The cytosols of the liver and kidneys contained 60% while those of the forebrain and spleen contained 30% of the total radioactivity found in the tissue homogenates. Gel filtration on Sephadex G-75 showed that all cytosols contained two peaks of radioactivity; a high molecular weight peak which eluted just after the void volume and a low molecular weight peak. The amount of radioactivity in both peaks was, however, much lower in the chromatographic peaks of the forebrain and spleen than that found in those of the liver and kidneys. Furthermore, the spleen had a comparatively very small low molecular weight radioactive peak. In vitro experiments with liver cytosol showed similar results to those found in vivo in that the high molecular weight radioactive peak could be removed by heat. It is concluded that silver does enter cells and that silver thionein exists in the cytosols of forebrain, spleen, kidney, and liver.

HEMODIALYSIS OF THE RAT

1966 ◽  
Vol 44 (5) ◽  
pp. 849-859 ◽  
Author(s):  
Sumner M. Robinson ◽  
David A. Hurwitz ◽  
Robert Louis-Ferdinand ◽  
William F. Blatt
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Low Molecular Weight

A technique is described for hemodialysis of either anesthetized or non-restrained rats. In the apparatus the dialysis plates of an autoanalyzer system are used with only minor modification. The efficiency of this method has been evaluated with regard to the clearance of saccharides, both in vitro and in vivo, as well as the extraction of nitrogenous low molecular weight moieties from circulating blood. Approximately 50% of the dialyzable material was obtained in a 1-hour dialysis. Further fractionation of the dialyzate was accomplished by gel filtration (Sephadex G-25).

In Vitro and in Vivo Antigen-Induced Release of High-Molecular Weight Neutrophil Chemotactic Activity from Human Nasal Tissue

1988 ◽  
Vol 2 (1) ◽  
pp. 7-11 ◽  
Author(s):  
T. Nagakura ◽  
T. Onda ◽  
Y. likura ◽  
T. Endo ◽  
H. Nagakura ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Nasal Polyps ◽  
Gel Filtration ◽  
Chemotactic Activity ◽  
Nasal Tissue ◽  
Nasal Secretions ◽  
Neutrophil Chemotactic Activity

High molecular weight neutrophil chemotactic activity has been identified in resected human nasal polyps, inferior turbinates, and nasal secretions following antigen challenge. The estimated molecular weight, by gel filtration chromatography, was approximately 600,000. However, a heterogeneity of molecular weight in some patients was recognized. Our results suggest a possible role for high molecular weight-neutrophil chemotactic activity in the pathogenesis of hypersensitivity in the human nasal cavity.

FRACTIONATION OF LIVER SOMATOMEDIN ACTIVITY BY ULTRAFILTRATION

1974 ◽  
Vol 62 (2) ◽  
pp. 355-361 ◽  
Author(s):  
JENNIFER M. DEHNEL ◽  
P. D. McCONAGHEY ◽  
M. J. O. FRANCIS
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Cartilage Growth ◽  
The Relationship ◽  
Somatomedin Inhibitors

SUMMARY Plasma somatomedin is the intermediary through which growth hormone (GH) exerts its effects on the growing skeleton. Somatomedin activity may be produced in vitro by perfusion of the liver and kidneys of rats with Waymouth's medium containing GH. The relationship between the activity of plasma somatomedin and somatomedin of hepatic and renal origin has yet to be clarified. Somatomedin from plasma can be separated into active fractions of both high and low molecular weight. Similarly, ultrafiltration of medium containing somatomedin of hepatic origin indicates the existence of two active fractions, one of high molecular weight (greater than 50000) and one of low molecular weight (less than 1000). The latter can be attributed to the release of amino acids, such as serine and glutamine, by the perfused tissue. The high molecular weight fraction is believed to represent GH-dependent somatomedin. Fractions that inhibit production of cartilage matrix are present in liver perfusates as well as in plasma. These results provide further evidence that the liver is a source of GH-dependent somatomedin in vivo. Furthermore, cartilage growth may be controlled not only by the GH-stimulated release of somatomedin by the liver, but also by its release of acid-labile somatomedin inhibitors.

scholarly journals Anticoagulant Activities of Lung and Mucosal Heparin

1977 ◽  
Author(s):  
T. W. Barrowcliffe ◽  
E. A. Johnson ◽  
C. A. Eggleton ◽  
D. P. Thomas
Keyword(s):  
Molecular Weight ◽  
Antithrombin Iii ◽  
Gel Filtration ◽  
High Ratio ◽  
Low Molecular Weight ◽  
Multiple Role ◽  
Heparin Activity ◽  
Molecular Weight Fractions

Interaction with antithrombin III is thought to be the main mechanism whereby heparin exerts an anticoagulant effect, but measurements of this specific heparin activity by an anti-Xa assay do not always agree with measurements made by ‘multiple role’ assays, such as APTT or pharmacopoeial assays. Two batches of lung heparin had APTT activities in vitro about 1.4 times those found by anti-Xa, whereas in several batches of porcine mucosal heparin this ratio was about 0.8. All assays by both methods were carried out against the 3rd International Standard for heparin. After gel filtration, lung heparin maintained a high ratio of APTT to anti-Xa activity in all except the low molecular weight fractions, where the two activities were both about 60 i. u./mg. In contrast, low molecular weight mucosal fractions had negligible APTT activity, but high (120 i. u./mg) activity by anti-Xa assay. A nominal 1000 units of lung heparin injected I. V. into volunteers gave peak anti-Xa levels of about 0.2 i. u./ml; a comparable injection of mucosal heparin gave peak levels of about 0.3 i. u./ml. The resulting ratio agreed with the anti-Xa activities of these two batches in vitro. However, in vivo, APTT levels with both heparins were less than half the anti-Xa levels, and 50 mins. after injection there was virtually no effect on the APTT, while heparin levels by anti-Xa remained about 0.1 i. u./ml. Although their APTT activities were comparable, lung heparin had much less anti-Xa potentiating effect than mucosal heparin, both in vitro and in vivo; this has important implications for the assay and clinical use of heparin.

scholarly journals The pupal cuticle of Drosophila: biphasic synthesis of pupal cuticle proteins in vivo and in vitro in response to 20-hydroxyecdysone.

1985 ◽  
Vol 101 (1) ◽  
pp. 189-200 ◽  
Author(s):  
J Doctor ◽  
D Fristrom ◽  
J W Fristrom
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ultrastructural Changes ◽  
Low Molecular Weight ◽  
Before And After ◽  
Cuticle Protein ◽  
Cuticle Proteins ◽  
Pupal Cuticle

We investigated the synthesis and localization of Drosophila pupal cuticle proteins by immunochemical techniques using both a complex antiserum and monoclonal antibodies. A set of low molecular weight (15,000-25,000) pupal cuticle proteins are synthesized by the imaginal disk epithelium before pupation. After pupation, synthesis of the low molecular weight proteins ceases and a set of unrelated high molecular weight proteins (40,000-82,000) are synthesized and incorporated into the pupal cuticle. Ultrastructural changes in the cuticle deposited before and after pupation correlate with the switch in cuticle protein synthesis. A similar biphasic accumulation of low and high molecular weight pupal cuticle proteins is also seen in imaginal discs cultured in vitro. The low molecular weight pupal cuticle proteins accumulate in response to a pulse of the insect steroid hormone 20-hydroxyecdysone and begin to appear 6 h after the withdrawal of the hormone from the culture medium. The high molecular weight pupal cuticle proteins accumulate later in culture; a second pulse of hormone appears to be necessary for the accumulation of two of these proteins.

On The Conversion Of High Molecular Weight Urokinase To The Low Molecular Weight Form

1981 ◽  
Author(s):  
Grant H Barlow ◽  
Charles W Francis ◽  
Victor J Marder
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Isotonic Saline ◽  
Low Molecular Weight ◽  
Plasmin Activity ◽  
Fibrin Plate ◽  
Gradient Gel Electrophoresis ◽  
Minute Duration

The conversion of high molecular weight urokinase (HMW) to low molecular weight urokinase (LWM) by plasmin in vitro has been studied. The two molecular weight forms of urokinase were separated by SDS polyacrylamide gradient gel electrophoresis and active enzyme extracted from gel segments into isotonic saline after slicing the gel at 5 mm intervals. Extracts from gel segments were analyzed by the fibrin plate method, and electrophoretic separation of the two forms were shown to be complete by comparison with the migration of purified standards and by the absence of lytic zones between the peaks of activity. HMW was incubated with plasminogen and fibrinogen for various time intervals from 2.5 to 10 minutes, enzymatic activity inhibited with aprotinin, and the samples subjected to electrophoresis. Conversion from HMW to LMW was apparent in as little as 2.5 minutes and continued for the 10 minute duration of the experiments. Similar experiments starting with LMW showed no change in molecular weight. Incubation of HMW without plasminogen resulted in no conversion to LMW implying that this reaction was not autocatalytic. The same conversion may occur in vivo during therapeutic administration of urokinase when a “lytic state” is produced and plasmin activity is present. Possible conversion of HMW to LMW in vivo will need to be considered in evaluating the relative therapeutic efficacy of different urokinase preparations and in interpreting the results of clinical trials.

Tumor Uptake of High and Low Molecular Weight Fractions from 67Ga-Citrate Labelled Blood Plasma

1984 ◽  
Vol 23 (02) ◽  
pp. 59-61 ◽  
Author(s):  
M. C. Crone ◽  
P. Thouvenot ◽  
F. Brunotte ◽  
C. Marchai ◽  
J. Robert ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Blood Plasma ◽  
High Molecular Weight ◽  
Gel Filtration ◽  
Weight Fraction ◽  
Blood Protein ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
67Ga Citrate

SummaryBlood plasma from tumor-bearing rats was incubated with 67Ga-citrate, and two fractions of high molecular weight (proteins) and low molecular weight were isolated by dialysis and by gel-filtration chromatography. Both fractions showed a different in vivo uptake by DS-sarcoma-bearing animals, the high molecular weight fraction being accumulated to a lesser extent. Compared to 67Ga-citrate the low molecular weight fraction showed a different uptake which for most tissues was significatively higher. This behavior suggests the presence of 67Ga in chemical forms other than citrate in the low molecular weight fraction. The lower uptake of the blood protein fraction is discussed.

Effects of Unfractionated and Low Molecular Weight Heparins on Platelet Thromboxane Biosynthesis “In Vivo”

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Primary Source ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
Heparin Administration ◽  
To Receive

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

1961 ◽  
Vol 06 (01) ◽  
pp. 015-024 ◽  
Author(s):  
Sven Erik Bergentz ◽  
Oddvar Eiken ◽  
Inga Marie Nilsson
Keyword(s):  
Molecular Weight ◽  
Body Weight ◽  
High Molecular Weight ◽  
Bleeding Time ◽  
Factor Vii ◽  
Low Molecular Weight ◽  
Factor V ◽  
Coagulation Mechanism ◽  
Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

1981 ◽  
Vol 46 (03) ◽  
pp. 612-616 ◽  
Author(s):  
U Schmitz-Huebner ◽  
L Balleisen ◽  
F Asbeck ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Day Treatment ◽  
Gel Filtration ◽  
Weight Fraction ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Platelet Factor ◽  
Heparin Fractions

SummaryHigh and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

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