scholarly journals Studies on the metabolism of rat liver copper-metallothionein

1985 ◽  
Vol 227 (3) ◽  
pp. 903-908 ◽  
Author(s):  
R K Mehra ◽  
I Bremner
Keyword(s):  
Rat Liver ◽  
Half Life ◽  
Pulse Labelling ◽  
Turnover Rates ◽  
Liver Cytosol ◽  
Total Liver ◽  
Liver Copper

The degradation of purified 35S-labelled rat liver isometallothioneins (MT) by lysosomal extracts was studied. Zn-MT-I was more readily hydrolysed than Zn-MT-II, but no significant degradation of the Cu-containing metallothioneins could be detected, even after 24 h incubation. The susceptibility of MT to degradation in vitro may be related to the strength of the metal-thiolate bonds. However, the turnover rates of cytosolic MT in vivo, as established by pulse-labelling techniques, are apparently subject to different controls. The half-lives of MT-I and -II in the liver cytosol of Cu2+-injected rats were only 15.4 +/- 1.5 and 18.2 +/- 1.1 h respectively. Approx. 25% of the total liver MT was present in particulate fractions (probably in lysosomes) of the liver and had a half-life of 25.1 +/- 4.1 h.

scholarly journals Heterogeneity and properties of hepatic dexamethasone-binding proteins

1979 ◽  
Vol 180 (1) ◽  
pp. 187-193 ◽  
Author(s):  
S L H Liu ◽  
T E Webb
Keyword(s):  
Rat Liver ◽  
Binding Proteins ◽  
Binding Protein ◽  
Novikoff Hepatoma ◽  
Liver Cytosol ◽  
Activated Complex ◽  
Simple Dissociation ◽  
Rat Liver Cytosol

Evidence from experiments in vivo and in vitro is presented for the presence of three species of dexamethasone-binding proteins in rat liver, which are identified by chromatography on Sepharose 6B or by isoelectric focusing. Although two of these species (DI and DII) possess properties characteristic of a true receptor, the third binding protein (i.e. DIII), which migrates most slowly on Sepharose 6B, but has stability properties similar to protein DII, exhibits a 3-fold lower affinity for dexamethasone and the activated complex neither binds to DNA-cellulose nor translocates to the nucleus. Only the predominant liver receptor (DI), which is eluted first from Sepharose 6B, is present in Novikoff-hepatoma cytosol, suggesting that the major and minor species are not interconverted through simple dissociation during their isolation. The binding activities of all three species in the liver cytosol increase approx. 2-fold in vivo after adrenalectomy and show a transient 2-fold fall in vivo after the administration of cortisol. These changes in vivo in protein DIII shows a marked lag compared with those in proteins DI and DII, which change in parallel. It is therefore proposed that rat liver cytosol contains two dexamethasone receptors and a dexamethasone-binding protein that may be derived from these receptors.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Half-Life of Platelet Factor 4 (PF-4) in Plasma and Platelets from Macaca Mulatta

1977 ◽  
Vol 37 (01) ◽  
pp. 073-080 ◽  
Author(s):  
Knut Gjesdal ◽  
Duncan S. Pepper
Keyword(s):  
Macaca Mulatta ◽  
Half Life ◽  
Human Platelet ◽  
Gel Filtration ◽  
Platelet Factor 4 ◽  
Active Protein ◽  
Platelet Factor ◽  
Membrane Bound

SummaryHuman platelet factor 4 (PF-4) showed a reaction of complete identity with PF-4 from Macaca mulatta when tested against rabbit anti-human-PF-4. Such immunoglobulin was used for quantitative precipitation of in vivo labelled PF-4 in monkey serum. The results suggest that the active protein had an intra-platelet half-life of about 21 hours. In vitro 125I-labelled human PF-4 was injected intravenously into two monkeys and isolated by immuno-precipita-tion from platelet-poor plasma and from platelets disrupted after gel-filtration. Plasma PF-4 was found to have a half-life of 7 to 11 hours. Some of the labelled PF-4 was associated with platelets and this fraction had a rapid initial disappearance rate and a subsequent half-life close to that of plasma PF-4. The results are compatible with the hypothesis that granular PF-4 belongs to a separate compartment, whereas membrane-bound PF-4 and plasma PF-4 may interchange.

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation
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