The Solubilizing Effect of Lysolecithin on the Extractability of Various Tissues of Rainbow Trout (Salmo gairdneri)

1971 ◽  
Vol 28 (12) ◽  
pp. 1837-1840
Author(s):  
R. E. E. Jonas
Keyword(s):  
Protein Solubility ◽  
Liver Homogenate ◽  
Fish Tissue ◽  
Lower Surface ◽  
Liver Mitochondria ◽  
Supernatant Fraction ◽  
Salmo Gairdneri ◽  
Total N ◽  
Tissue Homogenates ◽  
Liver Homogenates

Liver homogenate treated with and without lysolecithin (LL) and centrifuged at 1600 g and the supernatant portion centrifuged again at 20,000 g showed disintegration of organelles with disruption of their membranes in the pellet fractions of that which was treated with LL, whereas the organelles of the others were normal. This was seen from the electron micrographs of the pellet fractions. The amino acid composition of the protein fraction of the white skeletal muscle soluble in 0.9% NaCl and of the larger fraction extractable in 0.9% NaCl with LL added were similar. The total nitrogen found in the supernatant fraction of brain, kidney, and liver homogenates reached approximately 44, 59, and 63% in 0.9% NaCl and ≈ 88, 95, and 89% in 0.9% NaCl containing 4 mg/ml LL; whereas the total N present in heart muscle and white muscle homogenates reached approximately 39 and 31% in 0.9% NaCl and ≈ 61 and 51% in 0.9% NaCl containing 4 mg/ml LL. LL destroyed the ability of liver tissue and liver mitochondria to oxidize 14C palmitate. It was concluded that the effect of LL in increasing the amount of protein extractable from fish tissue homogenates arises from its ability to lower surface tension and disrupt membranes and not by affecting protein solubility.

scholarly journals Ca(2+)N It Be Measured? Detection of Extramitochondrial Calcium Movement With High-Resolution FluoRespirometry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna Nászai ◽  
Emil Terhes ◽  
József Kaszaki ◽  
Mihály Boros ◽  
László Juhász
Keyword(s):  
High Resolution ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Fluorescence Signal ◽  
Tissue Homogenates ◽  
Liver Homogenates ◽  
Isolated Liver ◽  
Duodenal Biopsies

AbstractOur aim was to develop a method to detect extramitochondrial Ca2+ movement and O2 fluxes simultaneously. Using High-Resolution FluoRespirometry, we also tested whether mitochondrial permeability transition pore (mPTP) inhibition or anoxia affects the mitochondrial Ca2+ flux. Ca2+ movement evoked by CaCl2 or anoxia was assessed with CaGreen-5N dye using Blue-Fluorescence-Sensor in isolated liver mitochondria, liver homogenates and duodenal biopsies. Exogenous CaCl2 (50 µM) resulted in an abrupt elevation in CaGreen-5N fluorescence followed by a decrease (Ca2+ uptake) with simultaneous elevation in O2 consumption in liver preparations. This was followed by a rapid increase in the fluorescence signal, reaching a higher intensity (Ca2+ efflux) than that of the initial CaCl2-induced elevation. Chelation of Ca2+ with EGTA completely abolished the fluorescence of the indicator. After pre-incubation with cyclosporin A, a marked delay in Ca2+ movement was observed, not only in isolated liver mitochondria, but also in tissue homogenates. In all samples, the transition to anoxia resulted in immediate increase in the level of extramitochondrial Ca2+. The results demonstrate that the CaGreen-5N method is suitable to monitor simultaneous O2 and Ca2+ fluxes, and the opening of mPTP in various biological samples. In this system the duration of stimulated Ca2+ fluxes may provide a novel parameter to evaluate the efficacy of mPTP blocker compounds.

FRACTIONATION OF MOUSE LIVER MICROSOMAL ESTERASES

1965 ◽  
Vol 43 (1) ◽  
pp. 97-104 ◽  
Author(s):  
C. Carruthers ◽  
E. Heins ◽  
A. Baumler
Keyword(s):  
Esterase Activity ◽  
Mouse Liver ◽  
Liver Homogenate ◽  
Deae Cellulose ◽  
Supernatant Fraction ◽  
Nonionic Detergent ◽  
Liver Homogenates ◽  
Two Peaks ◽  
Total Esterase Activity ◽  
Glycyl Glycine

Mouse liver microsomal esterases were fractionated on DEAE-cellulose after the solution of these enzymes in a solution containing 0.1 M glycyl glycine buffer, pH 7.0, and 5 × 10−4 M Lubrol W, a nonionic detergent. Elution of the enzymes from the DEAE-cellulose was accomplished by using NaCl in the glycyl glycine – Lubrol W solution. Microsomes isolated from sucrose and glycerol homogenates have three esterase peaks in common and two peaks not in common. The glycerol supernatant fraction from whole liver homogenate, which contains about 50% of the total esterase activity, and the sucrose supernatant fraction, which contains about 6% of the total esterase activity, have four common esterase peaks, one of which is different from both the microsomes isolated from glycerol and sucrose liver homogenates. Incorporation of Lubrol W in the solution that was employed for the elution of the esterases from the DEAE-cellulose was necessary to prevent extensive loss or inactivation of these enzymes. The nature of the changes induced by glycerol on liver esterases is briefly discussed.

scholarly journals Detection of CMP-N-acetylneuraminic acid hydroxylase activity in fractionated mouse liver

1989 ◽  
Vol 263 (2) ◽  
pp. 355-363 ◽  
Author(s):  
L Shaw ◽  
R Schauer
Keyword(s):  
Submandibular Gland ◽  
Mouse Liver ◽  
High Speed ◽  
Metal Salts ◽  
Supernatant Fraction ◽  
Inhibitory Influence ◽  
Hydroxylase Activity ◽  
Acetylneuraminic Acid ◽  
Liver Homogenates ◽  
High Speed Supernatant

The finding that N-glycoloylneuraminic acid (Neu5Gc) in pig submandibular gland is synthesized by hydroxylation of the sugar nucleotide CMP-Neu5Ac [Shaw & Schauer (1988) Biol. Chem. Hoppe-Seyler 369, 477-486] prompted us to investigate further the biosynthesis of this sialic acid in mouse liver. Free [14C]Neu5Ac, CMP-[14C]Neu5Ac and [14C]Neu5Ac glycosidically bound by Gal alpha 2-3- and Gal alpha 2-6-GlcNAc beta 1-4 linkages to fetuin were employed as potential substrates in experiments with fractionated mouse liver homogenates. The only substrate to be hydroxylated was the CMP-Neu5Ac glycoside. The product of the reaction was identified by chemical and enzymic methods as CMP-Neu5Gc. All of the CMP-Neu5Ac hydroxylase activity was detected in the high-speed supernatant fraction. The hydroxylase required a reduced nicotinamide nucleotide [NAD(P)H] coenzyme and molecular oxygen for activity. Furthermore, the activity of this enzyme was enhanced by exogenously added Fe2+ or Fe3+ ions, all other metal salts tested having a negligible or inhibitory influence. This hydroxylase is therefore tentatively classified as a monooxygenase. The cofactor requirement and CMP-Neu5Ac substrate specificity are identical to those of the enzyme in high-speed supernatants of pig submandibular gland, suggesting that this is a common route of Neu5Gc biosynthesis. The relevance of these results to the regulation of Neu5Gc expression in sialoglycoconjugates is discussed.

scholarly journals EFFECT OF GAMMA IRRADIATION ON THE DESOXYRIBONUCLEASE II ACTIVITY OF ISOLATED MITOCHONDRIA

1957 ◽  
Vol 3 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Shigefumi Okada ◽  
Lee D. Peachey
Keyword(s):  
Structural Damage ◽  
Liver Homogenate ◽  
Liver Mitochondria ◽  
Structural Elements ◽  
Dnase Ii ◽  
Mitochondrial Structure ◽  
Co60 Source ◽  
Mitochondrial Suspension ◽  
High Doses ◽  
Isolated Liver

1. Exposure of isolated liver mitochondria to high doses of gamma rays from a Co60 source causes the level of DNase II activity to increase. Treatment of the mitochondria with sonic vibration causes a further elevation of the activity to a level which is independent of the prior radiation dose. 2. Such increased mitochondrial DNase II activity appears to be due to the "structural damage" of the subcellular particulates caused by the ionizing radiation. Other methods of disrupting the mitochondrial structure also cause increased DNase II activity. A causal relationship between the structural alteration and the increased enzymatic activity is postulated. 3. The DNase II activity appears to be closely associated with the structural elements of the mitochondria and remains associated with the fragments after irradiation. 4. Upon irradiation, the mitochondrial suspension releases ultraviolet-absorbing materials which are probably nucleotide in nature. 5. The possibility of localization of DNase activity in the lysosome fraction of de Duve (15) is discussed. It is felt that DNase II is at least in part a mitochondrial enzyme and that probably the conclusions drawn here would be applicable to any DNase II present in the lysosomes as well. 6. Irradiation of whole liver homogenate causes no increased DNase II activity. The experiments do not provide any information on the presence or action of protective substances in the homogenate.

scholarly journals Features of free oxidation in liver homogenates of rats in combined action of copper and subtoxic level of stearate potassium and sodium

2016 ◽  
Author(s):  
O. V. Lototska
Keyword(s):  
Free Radical ◽  
Liver Homogenate ◽  
Sodium Stearate ◽  
Free Radical Oxidation ◽  
The Body ◽  
Antioxidant Systems ◽  
Radical Oxidation ◽  
Combined Action ◽  
Liver Homogenates ◽  
Free Oxidation

Toxic effects of heavy metals on animals and humans is aggravating the presence of surfactants. The aim of our research was to identify the peculiarities of free radical oxidation and antioxidant protection in the use of drinking water with subtoxic doses of potassium and sodium stearates in combination with copper on the body of warmblooded animals, such as the liver of experimental rats. Analysis of indicators allows asserting that in experimental rats liver homogenate observed activation of free radical oxidation, the intensity of which depended on the concentration of stearates in water. More pronounced changes were in animals that consumed water with potassium stearate.The action of potassium stearate observed inhibition of antioxidant systems while under the influence of sodium stearate – its activation. Changes in performance were more pronounced in combination stearates with copper.

Biosynthesis of 1,2-3H and 4-14C steroid sulfates of high specific activity

1970 ◽  
Vol 48 (1) ◽  
pp. 148-150 ◽  
Author(s):  
J. Torday ◽  
G. Hall ◽  
M. Schweitzer ◽  
C. J. P. Giroud
Keyword(s):  
Rat Liver ◽  
Specific Activity ◽  
Liver Homogenate ◽  
High Specific Activity ◽  
Supernatant Fraction ◽  
Metabolic Studies

A supernatant fraction of rat liver homogenate enriched with ATP was used for the biosynthesis of the ester sulfates of several 3H and 14C steroids of the pregn-4-ene series. The method provides a simple means to prepare steroid sulfates of high specific activity for use in either metabolic studies or as reference compounds in the quantification of such conjugates by isotope assays.

METHYLATION OF THE 3-OH POSITION OF CATECHOL ACIDS BY RAT LIVER AND KIDNEY PREPARATIONS

1958 ◽  
Vol 36 (5) ◽  
pp. 491-497 ◽  
Author(s):  
J. Pellerin ◽  
A. D'Iorio
Keyword(s):  
Enzymatic Activity ◽  
Rat Liver ◽  
Paper Chromatography ◽  
Reduced Glutathione ◽  
Liver Homogenate ◽  
Supernatant Fraction ◽  
Hydroxybenzoic Acid ◽  
Dihydroxybenzoic Acid ◽  
Kidney Homogenate ◽  
Liver And Kidney

3,4-Dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxymandelic acid, and 3,4-dihydroxycinnamic acid were separately incubated with L-methionine-methyl-C14 in the presence of rat liver or kidney homogenate. In each case, the radioactive metabolite separated by paper chromatography was found to have migrating properties similar to those of the 3-methoxy-4-hydroxyphenolic acid. This reaction was enhanced by the addition of ATP, Mg++, and reduced glutathione. When 3-hydroxybenzoic acid was incubated in this medium no methylated derivative was obtained. Preliminary experiments indicated that the enzymatic activity was contained mostly in the supernatant fraction. It was also noted that liver homogenate was much more active than kidney homogenate in methylating catechol acids.

GLYCINE METHYLTRANSFERASE

1963 ◽  
Vol 41 (1) ◽  
pp. 201-210 ◽  
Author(s):  
J. Blumenstein ◽  
G. R. Williams
Keyword(s):  
Secondary Amine ◽  
Liver Homogenate ◽  
Supernatant Fraction ◽  
Biological Oxidation ◽  
Methyl Group

The supernatant fraction of liver homogenate brings about the methylation of glycine by S-adenosylmethionine. The secondary amine formed in the reaction appears to be sarcosine. This conclusion is based on (I) the stoichiometry of the reaction, and (II) radioautography of chromatograms of the incubation products. The enzyme, glycine N-methyltransferase, was purified 80-fold, and certain of its characteristics are reported. The possible role of the enzyme in the biological oxidation of the methyl group of methionine is discussed.

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