Isolation of Novel Lignans, Heteroclitins F and G, from the Stems of Kadsura heteroclita, and Anti-lipid Peroxidative Actions of Heteroclitins A-G and Related Compounds in the in Vitro Rat Liver Homogenate System.

1992 ◽  
Vol 40 (6) ◽  
pp. 1510-1516 ◽  
Author(s):  
Xiu-Wei YANG ◽  
Hirotsugu MIYASHIRO ◽  
Masao HATTORI ◽  
Tsuneo NAMBA ◽  
Yasuhiro TEZUKA ◽  
...  
Keyword(s):  
Rat Liver ◽  
Liver Homogenate ◽  
Kadsura Heteroclita ◽  
Related Compounds

scholarly journals Differences in size, structure and function of free and membrane-bound polyribosomes of rat liver. Evidence for a single class of membrane-bound polyribosomes

1977 ◽  
Vol 168 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J C Ramsey ◽  
W J Steele
Keyword(s):  
Protein Synthesis ◽  
Rat Liver ◽  
Size Structure ◽  
Large Fraction ◽  
Liver Homogenate ◽  
Structure And Function ◽  
Structural And Functional Properties ◽  
Membrane Bound ◽  
And Function

Free loosely bound and tightly bound polyribosomes were separated from rat liver homogenate by salt extraction followed by differential centrifugation, and several of their structural and functional properties were compared to resolve the existence of loosely bound polyribosomes and verify the specificity of the separation. The free and loosely bound polyribosomes have similar sedimentation profiles and polyribosome contents, their subunit proteins have similar electrophoretic patterns and their products of protein synthesis in vitro show a close correspondence in size and amounts synthesized. In contrast, the tightly bound polyribosomes have different properties from those of the free and loosely bound polyribosomes; their average size is significantly smaller; their polyribosome content is higher; their 60 S-subunit proteins lack two components and contain four or more components not found elsewhere; their products of protein synthesis in vitro differ in size and amounts synthesized. These observations show that rat liver membranes entrap a large fraction of the free polyribosomes at low salt concentrations and that these polyribosomes are similar to those of the free-polyribosome fraction and are different from those of the tightly bound polyribosome fraction in size, structure and function.

A STUDY ON THE "IN VITRO" SYNTHESIS OF CITRULLINE: PART II. EFFECT OF GLUTAMIC ACID AND DERIVATIVES IN THE PRESENCE OF FUMARIC ACID

1964 ◽  
Vol 42 (9) ◽  
pp. 1325-1330 ◽  
Author(s):  
René Charbonneau ◽  
Louis Berlinguet
Keyword(s):  
Glutamic Acid ◽  
Rat Liver ◽  
Fumaric Acid ◽  
Liver Homogenate ◽  
Particulate Fraction ◽  
In Vitro Synthesis ◽  
System L ◽  
Acyl Derivatives

The role of N-carbamyl, N-acetyl, and L-glutamic acids with and without fumaric acid on the "in vitro" synthesis of citrulline was studied by using a particulate fraction obtained from a rat liver homogenate and a partially purified citrulline-synthesizing enzyme system. In the presence of a particulate fraction of rat liver homogenate, N-carbamyl and N-acetyl-L-glutamic acids are unable to replace L-glutamic acid, which is essential for citrulline biosynthesis. However, in the presence of fumaric acid, they both give a better synthesis of citrulline than L-glutamic acid alone. It is postulated that the acyl derivatives serve only in the transport of "activated CO2" whereas fumaric acid enters the citric acid to furnish the essential ATP molecules. Glutamic acid would be able to perform both functions. However, in the presence of a system containing partially purified citrulline-synthesizing enzymes, L-glutamic acid is unable to replace N-carbamyl and N-acetyl-L-glutamic acids with or without fumaric acid. In such a system, L-glutamic acid cannot serve in the transport of "activated CO2". It is postulated that L-glutamic acid must be acetylated prior to its utilization in this respect.With the particulate fraction of rat liver homogenate, N-allyl aspartic acid inhibits totally the synthesis of citrulline both in the presence and absence of fumaric acid with or without glutamic or N-acetyl glutamic acids. It probably interferes with the transport of "activated CO2".

scholarly journals Aqueous Extracts of Teucrium polium Possess Remarkable Antioxidant Activity In Vitro

2006 ◽  
Vol 3 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Predrag Ljubuncic ◽  
Suha Dakwar ◽  
Irina Portnaya ◽  
Uri Cogan ◽  
Hassan Azaizeh ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Rat Liver ◽  
Antioxidant Properties ◽  
Liver Homogenate ◽  
Plasma Oxidation ◽  
Teucrium Polium ◽  
Liver Homogenates ◽  
Β Carotene

Teucrium poliumL. (Lamiaceae) (RDC 1117) is a medicinal plant whose species have been used for over 2000 years in traditional medicine due to its diuretic, diaphoretic, tonic, antipyretic, antispasmodic and cholagogic properties. The therapeutic benefit of medicinal plants is often attributed to their antioxidant properties. We previously reported that an aqueous extract of the leaves and stems of this plant could inhibit iron-induced lipid peroxidation in rat liver homogenate at concentrations that were not toxic to cultured hepatic cells. Others have reported that organic extracts of the aerial components of this plant could inhibit oxidative processes. Against this background, we felt further investigation on the antioxidant action of the extract ofT. poliumprepared according to traditional Arab medicine was warranted. Accordingly, we assessed (i) its ability to inhibit (a) oxidation of β-carotene, (b) 2,2′-azobis(2-amidinopropan) dihydrochloride (AAPH)-induced plasma oxidation and (c) iron-induced lipid peroxidation in rat liver homogenates; (ii) to scavenge the superoxide ($${\hbox{ O }}_{2}^{\bullet -}$$) radical and the hydroxyl radical (OH•); (iii) its effects on the enzyme xanthine oxidase activity; (iv) its capacity to bind iron; and (v) its effect on cell glutathione (GSH) homeostasis in cultured Hep G2 cells. We found that the extract (i) inhibited (a) oxidation of β-carotene, (b) AAPH-induced plasma oxidation (c) Fe2+-induced lipid peroxidation in rat liver homogenates (IC50 = 7 ± 2 μg ml−1); (ii) scavenged $${\hbox{ O }}_{2}^{\bullet -}$$(IC50 = 12 ± 3 μg ml−1) and OH• (IC50 = 66 ± 20 μg ml−1); (iii) binds iron (IC50 = 79 ± 17 μg ml−1); and (iv) tended to increase intracellular GSH levels resulting in a decrease in the GSSG/GSH ratio. These results demonstrate that the extract prepared from theT. poliumpossesses antioxidant activityin vitro. Further investigations are needed to verify whether this antioxidant effect occursin vivo.

Diminished hepatic triiodothyronine production in Gunn rats

1986 ◽  
Vol 113 (2) ◽  
pp. 281-288 ◽  
Author(s):  
J. R. Saltzman ◽  
D. W. Clark ◽  
R. D. Utiger
Keyword(s):  
Thyroid Hormone ◽  
Rat Liver ◽  
Liver Homogenate ◽  
Unconjugated Bilirubin ◽  
Thyroid Hormone Metabolism ◽  
Gunn Rats ◽  
Deiodinase Activity ◽  
Sediment Fraction ◽  
Liver Homogenates

Abstract. The liver is a major site of conversion of thyroxine (T4) to the more active thyroid hormone 3,5,3'-triiodothyronine (T3). Hepatic T4 to T3 conversion is altered by a variety of pathological processes and pharmacological agents. We studied T4 to T3 conversion in glucuronyl transferase deficient homozygous Gunn rats because they have a hepatic enzyme abnormality which leads to hyperbilirubinaemia, and also because they have been reported to have alterations in thyroid hormone metabolism. An in vitro incubation system employing the 10 000 × g supernatant of liver homogenate was used, and T3 production was measured by radioimmunoassay. Experiments were done using substrate concentrations ranging from 0.56 to 20 μm, tissue protein in concentrations ranging from 0.625 to 20 mg and incubation times of 15 to 60 min. T3 production by liver homogenates from homozygous Gunn rats in these studies ranged from 29 to 70% of that produced by liver homogenates from phenotypically normal heterozygous Gunn rats. The deficit in hepatic T3 production by homozygous rats could not be overcome by increasing cofactor concentrations. After ultracentrifugation at 100 000 μ g, T4-5'-deiodinase activity was found primarily in the 100 000 × g sediment fraction. Homogygous rat liver 100 000 × g sediment T3 production was 55% of that of the heterozygous rat liver 100 000 × g sediment. Liver cytosol from both homozygous and heterozygous rats inhibited microsomal T4-5'-deiodinase activity similarly. Addition of unconjugated bilirubin to liver homogenates resulted in reduction of T3 production in livers from both homozygous and heterozygous rats. Thus the diminished capacity for hepatic conversion of T4 to T3 in homozygous Gunn rats may be due to inhibition of T4-5'-deiodinase activity by high endogenous levels of unconjugated bilirubin.

IN VITRO METABOLISM OF 17α-METHYL-1 9-NORTESTOSTERONE BY FEMALE RAT LIVER HOMOGENATE

1964 ◽  
Vol 46 (1) ◽  
pp. 40-46 ◽  
Author(s):  
Hiroji Okada ◽  
Kichisaburo Matsuyoshi ◽  
Gen-ichi Tokuda
Keyword(s):  
Rat Liver ◽  
Liver Homogenate ◽  
In Vitro Metabolism ◽  
Female Rat

ABSTRACT Incubation of 17α-methyl-19-nortestosterone-3H with female rat liver homogenate resulted in the formation of 17α-methyl-19-norandrostan-17β-ol-3-one-3H and 17α-methyl-19-norandrostane-3α,17β-diol-3H.

Some factors modifying the metabolism of AH 8165 by rat liver homogenate in vitro

1973 ◽  
Vol 25 (8) ◽  
pp. 657-658 ◽  
Author(s):  
B. Srinivasan ◽  
C. Wahdi ◽  
B. Pleuvry
Keyword(s):  
Rat Liver ◽  
Liver Homogenate

In vitro covalent binding of the pyrethroids cismethrin, cypermethrin and deltamethrin to rat liver homogenate and microsomes

1989 ◽  
Vol 63 (3) ◽  
pp. 214-220 ◽  
Author(s):  
R. Catinot ◽  
H. Hoellinger ◽  
M. Sonnier ◽  
Do-Cao-Thang ◽  
J. Pichon ◽  
...  
Keyword(s):  
Rat Liver ◽  
Covalent Binding ◽  
Liver Homogenate

scholarly journals THE EFFECT OF PODOPHYLLOTOXIN ON TISSUE METABOLISM AND ENZYME SYSTEMS

1949 ◽  
Vol 90 (6) ◽  
pp. 525-541 ◽  
Author(s):  
Zelma Baker Miller ◽  
Clarke Davison ◽  
Paul K. Smith
Keyword(s):  
Lymph Nodes ◽  
Rat Brain ◽  
Rat Liver ◽  
Chicken Embryo ◽  
Rat Kidney ◽  
Liver Homogenate ◽  
Rabbit Kidney ◽  
Toxic Dose ◽  
Kidney Homogenate

Podophyllotoxin, 10–3M, inhibits the respiration in vitro of rat lymph nodes, thymus, kidney, tumor, spleen, liver, brain, testis, and chicken embryo. Lymph node and spleen respiration are most sensitive, and the degree of inhibition increases with time. The injection of podophyllotoxin into tumor-bearing mice (20 mg. per kg.) causes a dramatic reduction in the respiration of tumor slices. Within 6 hours, the respiration approaches zero. Inhibition is evident 2 hours after injection of the drug. Spleen respiration is reduced 50 per cent within 6 hours. Kidney and liver respirations remain within normal limits. Marked reductions in the respiration of spleen, lymph nodes, and thymus glands of normal rats are produced by the injection of 15 mg. per kg. Thymus gland is the most sensitive of these three tissues, and its respiration is reduced 66 per cent 24 hours after injection of the drug. The injection of 0.8 microgram podophyllotoxin into the yolk sac of chicken eggs bearing 5 day embryos has no effect on the respiration of the embryo within 8 hours, although this is a sufficiently toxic dose to kill 80 per cent of the embryos (within 24 hours). Kidney respiration in the presence of acetate, glucose, alanine, and glutamate is inhibited to approximately the same degree as in the absence of added substrate. Succinate and pyruvate oxidation by rat kidney slices appear to be less sensitive. Oxidation of acetate and butyrate by rabbit kidney homogenate is more sensitive to podophyllotoxin than oxidation by rabbit kidney homogenate without added substrate. Glucose oxidation by this preparation is not inhibited by 10–3M podophyllotoxin. The anaerobic glycolysis of chicken embryo, rat brain, and rat testis is stimulated by 10–5 and 10–6M podophyllotoxin, and is inhibited by 10–3M. The following enzymes are not inhibited by 10–3M podophyllotoxin: succinoxidase from pigeon breast muscle, choline, xanthine and tyrosine oxidase from rat liver homogenate, and leucine oxidase from Proteus vulgaris; alkaline and acid phosphatase from dog serum; adenosine triphosphatase from rat liver; choline esterase from rat brain homogenate; ribonucleodepolymerase from spleen mince and thymonucleodepolymerase from dog serum. High concentrations of podophyllotoxin do not influence the viscosity and degree of polymerization of thymonucleic acid.

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