INTRACELLULAR DISTRIBUTION OF COPPER IN THE LIVER OF THE RAT

1967 ◽  
Vol 45 (12) ◽  
pp. 1841-1851 ◽  
Author(s):  
G. Gregoriadis ◽  
T. L. Sourkes
Keyword(s):  
Copper Content ◽  
Copper Deficiency ◽  
Physiological State ◽  
Intracellular Distribution ◽  
Subcellular Fractions ◽  
Absolute Amount ◽  
Newborn Rat ◽  
Adult Rat ◽  
Total Copper ◽  
Minor Losses

The absolute amount of copper in whole liver and its subcellular fractions decreases as the rat matures. The decrease in mitochondrial and nuclear fractions, which contain most of the copper in the liver of the newborn rat, is much greater than the decrease in the soluble and microsomal fractions. This results in a redistribution of the copper, in favor of the supernatant. In the adult rat, this fraction is about one-half the total copper content of the liver, with the content of nuclei, mitochondria, and microsomes following in that order. The intraperitoneal injection of copper sulfate or the feeding of a diet low in copper brings the copper content of the liver above and below normal levels, respectively, and affects the intracellular distribution as follows. In copper loading, mitochondria and nuclei hold most of the excess and the cytoplasm and microsomes accumulate much less. In copper deficiency, there is a greater loss of soluble and mitochondrial copper and there are minor losses in microsomes and nuclei. The copper concentration in subcellular fractions of the liver seems to be related to the total copper content of the organ rather than to the physiological state of the animal.

scholarly journals COX19 mediates the transduction of a mitochondrial redox signal from SCO1 that regulates ATP7A-mediated cellular copper efflux

2013 ◽  
Vol 24 (6) ◽  
pp. 683-691 ◽  
Author(s):  
Scot C. Leary ◽  
Paul A. Cobine ◽  
Tamiko Nishimura ◽  
Robert M. Verdijk ◽  
Ronald de Krijger ◽  
...  
Keyword(s):  
Copper Content ◽  
Copper Deficiency ◽  
Copper Ions ◽  
Dependent Manner ◽  
Copper Binding ◽  
Catalytic Core ◽  
Total Copper ◽  
Cellular Copper ◽  
Combined Deficiency ◽  
Copper Overload

SCO1 and SCO2 are metallochaperones whose principal function is to add two copper ions to the catalytic core of cytochrome c oxidase (COX). However, affected tissues of SCO1 and SCO2 patients exhibit a combined deficiency in COX activity and total copper content, suggesting additional roles for these proteins in the regulation of cellular copper homeostasis. Here we show that both the redox state of the copper-binding cysteines of SCO1 and the abundance of SCO2 correlate with cellular copper content and that these relationships are perturbed by mutations in SCO1 or SCO2, producing a state of apparent copper overload. The copper deficiency in SCO patient fibroblasts is rescued by knockdown of ATP7A, a trans-Golgi, copper-transporting ATPase that traffics to the plasma membrane during copper overload to promote efflux. To investigate how a signal from SCO1 could be relayed to ATP7A, we examined the abundance and subcellular distribution of several soluble COX assembly factors. We found that COX19 partitions between mitochondria and the cytosol in a copper-dependent manner and that its knockdown partially rescues the copper deficiency in patient cells. These results demonstrate that COX19 is necessary for the transduction of a SCO1-dependent mitochondrial redox signal that regulates ATP7A-mediated cellular copper efflux.

scholarly journals Ca2+-ATPase activity and Ca2+ uptake by sarcoplasmic reticulum in fish heart: effects of thermal acclimation.

1998 ◽  
Vol 201 (4) ◽  
pp. 525-532 ◽  
Author(s):  
E Aho ◽  
M Vornanen
Keyword(s):  
Atpase Activity ◽  
Uptake Rate ◽  
Teleost Fish ◽  
Crucian Carp ◽  
Thermal Acclimation ◽  
The Body ◽  
Newborn Rat ◽  
Fish Heart ◽  
Adult Rat ◽  
Uptake Velocity

This study was designed to compare the activities of sarcoplasmic (SR) Ca2+-ATPase and Ca2+ uptake in fish and mammalian hearts and to determine whether thermal acclimation has any effect on the function of the cardiac SR in fish. To this end, we measured thapsigargin-sensitive Ca2+-ATPase activity and thapsigargin-inhibitable Ca2+ uptake velocity in crude cardiac homogenates of newborn and adult rats and of two teleost fish (crucian carp and rainbow trout) acclimated to low (4 degrees C) and high (17 degrees C and 24 degrees C for trout and carp, respectively) ambient temperatures. The TG-sensitive Ca2+-ATPase activity was highest in adult rat, and the corresponding activities of cold-acclimated trout, warm-acclimated trout, warm-acclimated carp, cold-acclimated carp and newborn rat were 76, 58, 43, 28 and 23 %, respectively, of that of the adult rat at 25 degrees C. SR Ca2+ uptake velocity, measured using Fura-2 at room temperature (approximately 22 degrees C), was highest in cold-acclimated trout, and the values for adult rat, warm-acclimated trout, newborn rat, warm-acclimated carp and cold-acclimated carp were 93, 56, 24, 21 and 14 % of the uptake velocity of cold-acclimated trout, respectively. When corrected to the body temperature of the animal, the relative rates of SR Ca2+ uptake were 100, 26, 19, 18, 11 and 2 % for adult rat, newborn rat, cold-acclimated trout, warm-acclimated trout, warm-acclimated carp and cold-acclimated carp, respectively. These findings show that SR Ca2+ uptake is slower in fish than in mammalian hearts and that marked species-specific differences exist among teleost fish in this respect. Furthermore, acclimation to cold increases the Ca2+ uptake rate of trout cardiac SR (complete thermal compensation) but decreases the SR Ca2+ uptake rate of crucian carp heart. This difference in acclimation response probably reflects the different activity patterns of the two species in their natural habitat during the cold season.

scholarly journals Quantitative comparison of sarcomeric phosphoproteomes of neonatal and adult rat hearts

2008 ◽  
Vol 295 (2) ◽  
pp. H647-H656 ◽  
Author(s):  
Chao Yuan ◽  
Quanhu Sheng ◽  
Haixu Tang ◽  
Yixue Li ◽  
Rong Zeng ◽  
...  
Keyword(s):  
Protein Phosphorylation ◽  
Ion Trap ◽  
Physiological State ◽  
Phosphorylation Site ◽  
Mass Spectrometry Analysis ◽  
Specific Staining ◽  
Spectrometry Analysis ◽  
Sarcomeric Protein ◽  
Adult Rat ◽  
Rat Hearts

Neonatal hearts respond to stress and function in an environment quite different from adult hearts. There is evidence that these functional differences not only reflect modifications in the abundance and isoforms of sarcomeric proteins but also in the modulation of sarcomeric protein phosphorylation. Yet our understanding of changes in sarcomeric protein phosphorylation in development is incomplete. In the experiments reported here, we first quantified the intact sarcomeric protein phosphorylation status between neonatal and adult rat hearts by employing comparative two-dimensional (2-D) gel electrophoresis in conjunction with phosphoprotein-specific staining. Subsequently, we measured phosphorylation changes at the peptide level by employing high-resolution linear ion trap-Fourier transform (LTQ-FT) mass spectrometry analysis of titanium dioxide-enriched phosphopeptides differentially labeled with 16O/18O during in-gel digestion. We also employed Western blot analysis using phosphorylation site-specific antibodies to measure phosphorylation changes. Our data demonstrated the novel finding that phosphorylation levels of myosin-binding protein C (MyBP-C) at Ser295 and Ser315 as well as tropomyosin at Ser283 increased, whereas phosphorylation levels of MyBP-C at Ser320 and myosin light chain 2 at Ser15 decreased in neonatal hearts compared with the same sites in adult hearts. Although our data highlight the significant challenges in understanding relations between protein phosphorylation and cardiac function, they do support the hypothesis that developmental changes in the modulation of protein are functionally significant and correlate with the prevailing physiological state.

Nifedipine-activated Ca2+ permeability in newborn rat cortical collecting duct cells in primary culture

2001 ◽  
Vol 280 (5) ◽  
pp. C1193-C1203 ◽  
Author(s):  
Laura Valencia ◽  
Michel Bidet ◽  
Sonia Martial ◽  
Elsa Sanchez ◽  
Estela Melendez ◽  
...  
Keyword(s):  
Primary Culture ◽  
Transient Receptor Potential ◽  
Collecting Duct ◽  
Primary Cultures ◽  
Receptor Potential ◽  
Cortical Collecting Duct ◽  
Newborn Rat ◽  
Adult Rat ◽  
Intracellular Ca ◽  
Transient Receptor

To characterize Ca2+ transport in newborn rat cortical collecting duct (CCD) cells, we used nifedipine, which in adult rat distal tubules inhibits the intracellular Ca2+concentration ([Ca2+]i) increase in response to hormonal activation. We found that the dihydropyridine (DHP) nifedipine (20 μM) produced an increase in [Ca2+]i from 87.6 ± 3.3 nM to 389.9 ± 29.0 nM in 65% of the cells. Similar effects of other DHP (BAY K 8644, isradipine) were also observed. Conversely, DHPs did not induce any increase in [Ca2+]i in cells obtained from proximal convoluted tubule. In CCD cells, neither verapamil nor diltiazem induced any rise in [Ca2+]i. Experiments in the presence of EGTA showed that external Ca2+ was required for the nifedipine effect, while lanthanum (20 μM), gadolinium (100 μM), and diltiazem (20 μM) inhibited the effect. Experiments done in the presence of valinomycin resulted in the same nifedipine effect, showing that K+ channels were not involved in the nifedipine-induced [Ca2+]i rise. H2O2also triggered [Ca2+]i rise. However, nifedipine-induced [Ca2+]i increase was not affected by protamine. In conclusion, the present results indicate that 1) primary cultures of cells from terminal nephron of newborn rats are a useful tool for investigating Ca2+transport mechanisms during growth, and 2) newborn rat CCD cells in primary culture exhibit a new apical nifedipine-activated Ca2+ channel of capacitive type (either transient receptor potential or leak channel).

Intracellular distribution of tritiated bilirubin during hepatic uptake and excretion

1964 ◽  
Vol 207 (6) ◽  
pp. 1237-1241 ◽  
Author(s):  
William R. Brown ◽  
Gerold M. Grodsky ◽  
John V. Carbone
Keyword(s):  
Serum Bilirubin ◽  
Hepatic Uptake ◽  
Hepatic Cell ◽  
Intracellular Distribution ◽  
Constant Function ◽  
Subcellular Fractions ◽  
Acid Hydrolase ◽  
Bilirubin Concentration ◽  
Extrahepatic Tissues

Physiologic amounts of bilirubin-H3 were injected into normal rats and the distribution of isotope was determined in serum, subcellular fractions of the liver, and bile at intervals during the phases of uptake and excretion. Recovery in the three spaces after 2, 5, 15, and 30 min was 75–85%, indicating little bilirubin entered the extrahepatic tissues. At 5 min, 50% of the dose (excluding trapped serum bilirubin-H3) was in the liver, a bilirubin concentration greater than in serum; biliary excretion of bilirubin was less than 3%. By 30–60 min, most of the label was excreted in the bile as intact, diazotizable and crystallizable bilirubin. Bilirubin-H3 appeared principally in the hepatic cell sap at a rate and concentration too high for an albumin-linked transfer. No differences in the distribution of isotope in subcellular fractions were detectable during the phases of uptake or excretion or when the quantity injected was increased 20–40 times. Thus, intracellular distribution was primarily a constant function of intracellular bilirubin concentration. When compared to in vitro experiments, significant amounts of bilirubin accumulated within the microsomes and the acid hydrolase-rich fraction (lysosomes) but not in the mitochondrial or nuclear fractions.

Reacted copper(II) concentrations in earlywood and latewood of micronized copper-treated Canadian softwood species

Holzforschung ◽  
2015 ◽  
Vol 69 (4) ◽  
pp. 509-512 ◽  
Author(s):  
Wei Xue ◽  
Pierre Kennepohl ◽  
John N.R. Ruddick
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Fluorescence Spectroscopy ◽  
Copper Content ◽  
Red Pine ◽  
Western Hemlock ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Total Copper ◽  
Electron Paramagnetic ◽  
Softwood Species

Abstract Electron paramagnetic resonance was used in conjunction with X-ray fluorescence spectroscopy to quantify total copper and reacted copper retentions in MCQ and MCA treated Canadian red pine sapwood and western hemlock heartwood. Total copper retentions were distinctly different between earlywood and latewood of both softwood species examined. Earlywood of red pine sapwood had higher total copper content than the latewood, while western hemlock heartwood had higher total copper contents in latewood than earlywood. The reacted copper concentrations were similar in earlywood and latewood, reflecting a similar capacity of each to solubilize and complex the reacted copper.

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