scholarly journals The effect of adrenocorticotrophin on protein degradation in rat adrenal gland and liver

1974 ◽  
Vol 144 (2) ◽  
pp. 397-402 ◽  
Author(s):  
J A Canick ◽  
D B Villee
Keyword(s):  
Adrenal Gland ◽  
Protein Degradation ◽  
Rat Liver ◽  
Exponential Decay ◽  
Total Protein ◽  
Mitochondrial Protein ◽  
Pool Size ◽  
Subcellular Fractions ◽  
The Mean

The rate of adrenal protein degradation appears to be slower in rats to which ACTH (adrenocorticotrophin) has been chronically administered. As measured by the exponential decay of radioactively labelled adrenal protein in vivo, the mean half-lives of total protein and of mitochondrial, microsomal and 18000g-supernatant protein were significantly longer in ACTH-treated animals. Experiments in which either [3H]leucine or NaH14CO3 was used to label proteins showed that of the fractions studied, the effect on mitochondrial protein degradation was most pronounced. The half-lives of the same subcellular fractions in rat liver were not affected by ACTH. The possibility that the results might have been caused by changes in radioisotope reutilization and pool size is discussed.

scholarly journals The availability of inorganic sulphate in blood for sulphate conjugation of drugs in rat liver in vivo. (35S)Sulphate incorporation into harmol sulphate

1978 ◽  
Vol 172 (2) ◽  
pp. 247-251 ◽  
Author(s):  
G J Mulder ◽  
E Scholtens
Keyword(s):  
Plasma Concentration ◽  
Rat Liver ◽  
Biliary Excretion ◽  
Time Course ◽  
Specific Radioactivity ◽  
Pool Size ◽  
Inorganic Sulphate ◽  
Initial Decrease ◽  
Sulphate Conjugate

1. When Na235SO4 is injected intravenously in rats, it is immediately available for sulphate conjugation of the phenolic drug harmol (7-hydroxyl-1-methyl-9H-pyrido[3,4-b]indole) in the liver. This was established by following the time course of the biliary excretion of the sulphate conjugate of harmol, and the incorporation of [35S]sulphate into harmol sulphate. 2. During the 10min immediately after injection of Na235SO4 re-distribution of [35S]sulphate took place, which resulted in a rapid initial decrease in the plasma concentration of [35S]sulphate; a concomitant decrease in the amount of [35S]sulphate incorporated into harmol sulphate was observed, indicating that the co-substrate of sulphation, adenosine 3′-phosphate 5′-sulphatophosphate, equilibrates rapidly with [35S]sulphate in plasma. 3. The results suggest that the pool size of adenosine 3′-phosphate 5′-sulphatophosphate is very small; therefore the specific radioactivity of [35S]sulphate in plasma determines the specific radioactivity incorporated into sulphate esters at any time.

scholarly journals Ultrasonic Heating Detects Lipiodol Deposition within Liver Tumors after Transarterial Embolization: An In Vivo Approach

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 901
Author(s):  
Natsuhiko Saito ◽  
Toshihiro Tanaka ◽  
Kiyoyuki Minamiguchi ◽  
Ryosuke Taiji ◽  
Hideyuki Nishiofuku ◽  
...  
Keyword(s):  
Sound Velocity ◽  
Temperature Coefficient ◽  
Rat Liver ◽  
Liver Tumors ◽  
Transarterial Embolization ◽  
Rate Of Change ◽  
Accumulation Ratio ◽  
Ct Value ◽  
The Mean

Computed tomography (CT) is the standard method to evaluate Lipiodol deposition after transarterial embolization (TAE) for a long period. However, iodine but not Lipiodol can be observed on CT. A minimally invasive other method to detect Lipiodol has been needed to evaluate accurate evaluation after procedure. The purpose of this study was to evaluate the efficacy of using the rate of change in sound velocity caused by ultrasonic heating to reflect Lipiodol accumulation after TAE in a rat liver tumor model. We analyzed the association of this developed technique with CT images and histological findings. Eight rats bearing N1S1 cells were prepared. After confirmation of tumor development in a rat liver, Lipiodol was injected via the hepatic artery. Seven days after TAE, CT scan and sound velocity changes caused by ultrasonic heating were measured, and then the rats were sacrificed. An ultrasonic pulse-echo method was used to measure the sound velocity. The temperature coefficient of the sound velocity in each treated tumor was evaluated and compared with the mean CT value and the histological Lipiodol accumulation ratio. Pearson’s correlation coefficients were calculated to assess the correlation between the measured values. The correlation coefficient (r) of the mean CT value and histological Lipiodol accumulation ratio was 0.835 (p = 0.010), which was considered statistically significant. Also, those of the temperature coefficient of the sound velocity and the histological Lipiodol accumulation ratio were statistically significant (r = 0.804; p = 0.016). To our knowledge, this is the first study that reported the efficacy of ultrasonic heating to detect Lipiodol accumulation in rat liver tumors after TAE. Our results suggest that the rate of change in sound velocity caused by ultrasonic heating can be used to evaluate Lipiodol accumulation in liver tumors after TAE, and thus could represent an alternative to CT in this application. This new innovative technique is easy to treat and less invasive in terms of avoiding radiation compared with CT.

scholarly journals Stable enhancement of calcium retention in mitochondria isolated from rat liver after the administration of glucagon to the intact animal

1978 ◽  
Vol 176 (3) ◽  
pp. 705-714 ◽  
Author(s):  
Veronica Prpić ◽  
Terry L. Spencer ◽  
Fyfe L. Bygrave
Keyword(s):  
Rat Liver ◽  
Molecular Mechanisms ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Mitochondrial Protein ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Matrix Space ◽  
The Matrix

1. Mitochondria isolated from rat liver by centrifugation of the homogenate in buffered iso-osmotic sucrose at between 4000 and 8000g-min, 1h after the administration in vivo of 30μg of glucagon/100g body wt., retain Ca2+ for over 45min after its addition at 100nmol/mg of mitochondrial protein in the presence of 2mm-Pi. In similar experiments, but after the administration of saline (0.9% NaCl) in place of glucagon, Ca2+ is retained for 6–8min. The ability of glucagon to enhance Ca2+ retention is completely prevented by co-administration of 4.2mg of puromycin/100g body wt. 2. The resting rate of respiration after Ca2+ accumulation by mitochondria from glucagon-treated rats remains low by contrast with that from saline-treated rats. Respiration in the latter mitochondria increased markedly after the Ca2+ accumulation, reflecting the uncoupling action of the ion. 3. Concomitant with the enhanced retention of Ca2+ and low rates of resting respiration by mitochondria from glucagon-treated rats was an increased ability to retain endogenous adenine nucleotides. 4. An investigation of properties of mitochondria known to influence Ca2+ transport revealed a significantly higher concentration of adenine nucleotides but not of Pi in those from glucagon-treated rats. The membrane potential remained unchanged, but the transmembrane pH gradient increased by approx. 10mV, indicating increased alkalinity of the matrix space. 5. Depletion of endogenous adenine nucleotides by Pi treatment in mitochondria from both glucagon-treated and saline-treated rats led to a marked diminution in ability to retain Ca2+. The activity of the adenine nucleotide translocase was unaffected by glucagon treatment of rats in vivo. 6. Although the data are consistent with the argument that the Ca2+-translocation cycle in rat liver mitochondria is a target for glucagon action in vivo, they do not permit conclusions to be drawn about the molecular mechanisms involved in the glucagon-induced alteration to this cycle.

Stereoselective glutathione conjugation of the separate α-bromoisovalerylurea and α-bromoisovaleric acid enantiomers in the rat in vivo and in rat liver subcellular fractions

1988 ◽  
Vol 37 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Johan M. te Koppele ◽  
Sandra W. Esajas ◽  
Johannes Brussee ◽  
Arne van der Gen ◽  
Gerard J. Mulder
Keyword(s):  
Rat Liver ◽  
Subcellular Fractions ◽  
Glutathione Conjugation

Ouabain is secreted by the adrenal gland in awake dogs

1993 ◽  
Vol 264 (3) ◽  
pp. E413-E419 ◽  
Author(s):  
B. R. Boulanger ◽  
M. P. Lilly ◽  
J. M. Hamlyn ◽  
J. Laredo ◽  
D. Shurtleff ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Blood Volume ◽  
Random Order ◽  
Paired Samples ◽  
Arterial Blood ◽  
Blood Volume Expansion ◽  
The Mean ◽  
Arterial Plasma ◽  
Adrenal Secretion

Ouabain has been identified in the plasma and adrenal glands of several mammals, including humans. To investigate possible adrenal secretion of ouabain in vivo, at rest, and in response to acute blood volume changes, we prepared trained adult dogs (n = 10) with splenectomy and unilateral adrenal venous (AV) cannulation. Two days later, after an overnight fast, dogs had either 1) 20% hemorrhage (hem) or 2) 20% blood volume expansion (exp; 6% Dextran 70, 0.9% NaCl) in random order. In AV and arterial plasma (ART), ouabain was measured by a ouabain-specific immunoassay, and cortisol and aldosterone were measured by radioimmunoassay. ART and AV ouabain concentration did not change after hem or exp [P = not significant (NS)]. In 94 of 97 paired samples, the concentration of ouabain in AV was greater than that in ART (Wilcoxon, P < 0.001), and the mean ouabain concentration was greater in AV (756.4 +/- 85.7 pmol/l) than ART (235.4 +/- 18.5 pmol/l; P < 0.001). The mean AV-to-ART ouabain concentration ratio was 5.7 +/- 1.29. Adrenal secretion of ouabain was not influenced by hem or exp (analysis of variance, P = NS). Adrenal secretion of cortisol and aldosterone increased after hem (P < 0.05) and was unaltered by exp (P = NS). This study demonstrates that ouabain is secreted by the adrenal gland in the awake dog. However, adrenal ouabain secretion and arterial blood ouabain are not altered by acute hem or exp.

scholarly journals Role of membrane-bound and free polyribosomes in the synthesis of cytochrome c in rat liver

1974 ◽  
Vol 140 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Néstor F. González-Cadavid ◽  
Carmen Sáez De Córdova
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Rat Liver ◽  
Cell Structure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mitochondrial Protein ◽  
Sodium Dodecyl ◽  
Membrane Bound

The functional distinction of membrane-bound and free polyribosomes for the synthesis of exportable and non-exportable proteins respectively is not so strict as was initially thought, and it was therefore decided to investigate their relative contribution to the elaboration of an internal protein integrated into a cell structure. Cytochrome c was chosen as an example of a soluble mitochondrial protein, and the incorporation of [14C]leucine and δ-amino[14C]laevulinate into the molecule was studied by using different ribosomal preparations from regenerating rat liver. A new procedure was devised for the purification of cytochrome c, based on ion-exchange chromatography combined with sodium dodecyl sulphate–polyacrylamide-gel electrophoresis. In spite of cytochrome c being a non-exportable protein, the membrane-bound polyribosomes were at least as active as the free ribosomes in the synthesis in vitro of the apoprotein and the haem moiety. The detergent-treated ribosomes could also effect the synthesis of cytochrome c, although at a lower rate. Since in liver more than two-thirds of the ribosomes are bound to the endoplasmic-reticulum membranes, it is considered that in vivo they are responsible for the synthesis of most of the cytochrome c content of the cell. This suggests that in secretory tissues the endoplasmic reticulum plays a predominant role in mitochondrial biogenesis, although free ribosomes may participate in the partial turnover of some parts of the organelle. The hypothesis on the functional specialization of the different kinds of ribosomes was therefore modified to account for their parallel intervention in the synthesis of proteins associated with membranous structures.

scholarly journals Effect of hypophysectomy on the rates of protein synthesis and degradation in rat liver

1979 ◽  
Vol 178 (3) ◽  
pp. 725-731 ◽  
Author(s):  
R D Conde
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Rat Liver ◽  
Protein Metabolism ◽  
Plasma Proteins ◽  
Degradation Rates ◽  
Hypophysectomized Rats ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

The effect of hypophysectomy on the protein metabolism of the liver in vivo was studied. Fractional rates of protein synthesis and degradation were determined in the livers of normal and hypophysectomized rats. Synthesis was measured after the injection of massive amounts of radioactive leucine. Degradation was estimated either as the balance between synthesis and accumulation of stable liver proteins or from the disappearance of radioactivity from the proteins previously labelled by the injection of NaH14CO3. The results indicate that: (1) hypophysectomy diminishes the capacity of the liver to synthesize proteins in vivo, mainly of those that are exported as plasma proteins; (2) livers of both normal and hypophysectomized rats show identical protein-degradation rates, whereas plasma proteins are degraded slowly after hypophysectomy.

scholarly journals DIRECT COUNTING AND SIZING OF MITOCHONDRIA IN SOLUTION

1972 ◽  
Vol 54 (2) ◽  
pp. 325-345 ◽  
Author(s):  
Adrian R. L. Gear ◽  
Jana M. Bednarek
Keyword(s):  
Electron Microscopy ◽  
Rat Liver ◽  
Rat Kidney ◽  
Mitochondrial Protein ◽  
Kidney Cortex ◽  
Rat Liver Mitochondria ◽  
Particle Volume ◽  
Drug Induced ◽  
Rat Kidney Cortex ◽  
The Mean

Resistive particle counting has been developed for the accurate sizing and counting of mitochondria in solution. The normal detection limit with a 30 µ aperture is 0.48 µ diameter, or 0.056 µ3 particle volume The mean volume of rat liver mitochondria was 0.42 µ3 or 0.93 µ in diameter. The average value for numbers of particles per milligram of mitochondrial protein was 4.3 x 103, and per gram of rat liver was about 11 x 1010. These values compare satisfactorily with those derived by light microscopy and electron microscopy. The mean volume for mitochondria from rat heart was 0 60 µ3 and from rat kidney cortex, 0.23 µ3. These values agree within 15% of those determined by electron microscopy of whole tissue. Mitochondrial fragility and contaminating subcellular organelles were shown to have little influence on the experimentally determined size distributions The technique may be applied to rapid swelling studies, as well as to estimations of the number and size of mitochondria from animals under different conditions such as liver regeneration and hormonal, pathological, or drug-induced states Mitochondrial DNA, RNA, cytochrome c-oxidase, cytochrome (a ÷ a3), and iron were nearly constant per particle over large differences in particle size. Such data may be particularly valuable for biogenesis studies and support the hypothesis that the net amount per particle of certain mitochondrial constituents remains constant during mitochondrial growth and enlargement

scholarly journals Enzymic oxidation of unconjugated bilirubin by rat liver

1986 ◽  
Vol 236 (3) ◽  
pp. 625-633 ◽  
Author(s):  
R Cardenas-Vazquez ◽  
O Yokosuka ◽  
B H Billing
Keyword(s):  
Ionic Strength ◽  
Rat Liver ◽  
Mitochondrial Protein ◽  
Subcellular Fractionation ◽  
Sprague Dawley ◽  
Bilirubin Oxidase ◽  
Outer Membranes ◽  
The Media ◽  
The Mean

The presence of the enzyme bilirubin oxidase, which degrades bilirubin in vitro, was demonstrated in the liver. Subcellular-fractionation experiments indicate that bilirubin oxidase is located in both the inner and outer membranes of the mitochondria. The mean rate of the reaction is 1.57 +/- 0.38 (S.D.) nmol of bilirubin degraded/min per mg of mitochondrial protein (munits/mg of protein). With respect to the overall breakdown of bilirubin, the enzyme has a Km' of 136 microM-bilirubin and a Vmax.' of 9.13 munits/mg of protein. Its activity is influenced by the ionic strength of the media and is inhibited by KCN, thiol reagents, NADH and albumin. The enzyme is aerobic, and between 1 and 1.5 mol of O2 are consumed per mol of bilirubin degraded. The products of the reaction include propentdyopents. The hepatic bilirubin oxidase activity of the jaundiced Gunn-rat liver is not significantly different from that of the Sprague-Dawley rat, and it is not induced by beta-naphthoflavone.

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