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At least 19 recordsLinked to original sources
PubMed1977

[Liver extract effect on liver microsomal system and on an experimental model of intoxication].

A lyophilized liver extract (FLR) lengthens hexobarbital action in control rats ; it decreases slightly the induction of hepatic microsomal enzymes and normalizes diphenylhydantoin protection against electroshock seizure in phenobarbital-treated animals ; in the event of a CC14 intoxication, this extract reestablishes values close to normal for mebubarbital metabolism in mice and for BSP clearance in rats. FLR could act in regularizing drug metabolism.

Animals↗
PubMed1977

In vitro inhibition of tritiated thymidine uptake in Morris hepatoma cells by normal rat liver extract: a possible liver chalone.

A phosphate-buffered saline extract of normal rat liver tissue almost completely inhibited DNA synthesis in Buffalo rat Morris hepatoma 7777 cells in vitro. This effect was tissue-specific because it did not occur with extracts of kidney, spleen, heart, lung, muscle, and hepatoma. The liver extracts did not inhibit in vitro human prostate carcinoma or phytohemagglutinin-stimulated human and rat peripheral blood lymphocyte cultures. The addition of 10% fetal calf serum in the incubation medium had no effect on this inhibition. We determined that doses of liver extract that inhibit thymidine incorporation were not toxic inasmuch as treated cells remained viable, as indicated by trypan blue exclusion. The liver extract may thus contain a cell-specific mitotic inhibitor, a chalone for hepatoma cells.

Animals↗
PubMed1990

[A comparative study of the action of liver extracts from C57Bl and CBA mice on hepatocyte adhesion].

The adhesiometric methods were used for the investigation of influence of the preparations extracted from liver of CBA mice, predisposed to spontaneous blastomogenesis, and stable C57BL mice on cell adhesion. The extraction was carried out at 4 degrees C or 20 degrees C under condition of Ca2(+)-deficiency, so four preparations were investigated. The differences in adhesive activity between these liver preparations of two mouse lines were determined. The influence of the liver extracts (20 degrees C) from C57BL and CBA mice on cell adhesion was different. These preparations from C57BL mice contained the cell surface and membrane connected adhesion factors. The liver extracts (4 degrees C) from C57BL mice contained the cell surface adhesion factors influenced adhesive properties of hepatocytes under condition of cell surface preservation, and acted only on hepatocytes of C57BL mice. Our results concluded that, first, there were different adhesion factors extracted at 4 degrees C and 20 degrees C in liver preparations from C57BL mice; second, there was the strong change in cell surface of CBA mouse hepatocytes.

Animals↗
PubMed1977

Effect of mercurascan and tetracycline on ischaemia-altered immunogenicity of liver extract alloantigens in mice.

The action of Mercurascan and Tetracycline on ischaemic liver in mice was investigated. The effect was reflected in different immunogenicity (in allotrasplantation reaction) of liver extracts 1 mg. membrane fraction) derived from treated and normal organs in the donor--recipient strain combination B10--B10.LP. In the recipients treated with a single administration of extract from ischaemic liver the survival time of skin grafts was shortened as compared to the untreated control group and the control group given normal liver extract. Immunogenicity of the liver extracts from Mercurascan- or Tetracycline-treated mice was diminished.

Animals↗
PubMed1975

[Inhibition of the incorporation of tritiated thymidine in fetal rat liver in cell culture by a fractioned liver extract].

A dialyzed rat liver extract has been chromatographed on "Sephadex G 25" and then on "Sephadex G 50". Thus we found a fraction which inhibits the incorporation of tritiated thymidine and stimulates the incorporation of labelled orotic acid into foetal rat liver cells in culture, but has no effect on DNA synthesis in cell lines derived from lymphocytes and fibroblasts.

Animals↗
PubMed1975

Double-blind study of a total liver extract in patients with hepatic dysfunction.

Forty hospitalized male patients with hepatic functional deficit were treated i.m. for 3 weeks with a total liver extract or placebo. The study was a double-blind. Statistical analysis (Student's t test, analysis of variance. Mann-Whitney test and Fisher's probability test) showed that liver extract therapy was more effective than placebo in improving liver function as indicated by changes in clinical features(digestive disorders, constipation, hepatomegaly) and colloidal and other laboratory tests, e.g. plasma cholesterol, prothrombin time, red cell count and hemoglobin concentration. An overall clinical assessment showed that 60% of patients treated with the liver extract were improved. In addition, no local or general side effects were observed. Present results are in favour of an hepatoprotective activity of a total liver extract.

Adult↗
PubMed1976

The intestinal phase of gastric secretion. Response to liver extract infusion into the proximal jejunum of healthy human subjects.

A Levine tube was placed under radiological control in the stomach, and a thin polyethylene tube in the proximal jejunum of 6 healthy volunteers. The stomach and proximal part of jejunum were perfused for 2 hours with 1% acetylcholine, 20% meat extract (Bovril), and 15% liver extract (LE) alone and in combination with simultaneous infusion of different doses of exogenous pentagastrin intravenously. A significant increase in serum gastrin concentration was found with antral perfusion of LE only, whereas perfusion of the proximal jejunum did not change the basal level of the serum gastrin concentration. No change from control values was observed in gastric acid, and pepsin output on perfusing proximal jejunum with LE alone, or in combination with pentagastrin. Reflux to the stomach varied between 0-1.4%, as determined by addition of radioactive B12 to the perfusates. The experiments showed that gastrin was released from the antrum of the stomach by perfusion with 15 per cent LE, but not from the jejunum under the present experimental conditions. In the present experiments Bovril and acetylcholine perfusions did not cause significant responses from the antrum or from the proximal jejunum.

Acetylcholine↗
PubMed1976

Inhibition of protein and nucleic acid synthesis of animal cells in vitro mediated by high molecular weight inhibitors in human liver extract.

1. The addition of human liver extract to HeLa cells induces a reversible inhibition of the incorporation of [3H] thymidine into the DNA, [3H] uridine into the RNA, and 14C-labelled amino acids into the protein of HeLa cells. The inhibitory effects appear after treatment for 1 h and reach a maximum after 4-8 h. These effects do not depend on a defective precursor penetration, isotopic dilution or degradation of labelled precursor (thymidine-degrading enzymes were inactivated by the addition of unlabelled thymine), reduced activity of thymidine and uridine kinase, medium impairment, or an impairment of the cell-membrane function. 2. The nucleic acid synthesis-inhibiting activity of the extract seems to be dependent on cellular protein synthesis but independent of RNA synthesis which indicates that the inhibitors act in an indirect way. Furthermore, the inhibitors seem to lack the tissue-specific character of chalones. 3. The extract contains separate inhibitors of DNA, RNA and protein synthesis. These inhibitors were found to have different physical-chemical characteristics and to be macromolecules with a protein or conjugated protein character (mol. wt. approx. 90 000). 4. The possibility that the activity of the high molecular weight inhibitors resides in low molecular weight factors (bound to protein carriers) was tested: No true low molecular weight inhibitors could be liberated by extraction with trichloroacetic acid/organic solvents or by dialysis/enzymatic treatments. Nucleosides such as thymidine, uridine, and cytidine, however, were liberated and could be shown to interfere with the uptake of [3H] thymidine/[3H] uridine.

Cell Line↗
PubMed1991

1H NMR analyses of methyl group-containing metabolites in rat liver extracts--effects of starvation, anoxia, acute glycerol and carbon tetrachloride treatment and chronic ethanol administration on hepatic metabolism.

400 MHz 1H NMR spectroscopy was used to analyze methyl group-containing metabolites in perchloric acid extracts of livers of rats treated with carbon tetrachloride or fed with ethanol-containing liquid diets, and sacrificed with carbon dioxide anoxic euthanasia or pentobarbital euthanasia (with or without 12-18 hour fasting). In all cases, coenzyme A was detected using 1H NMR spectroscopy, but at higher levels for chronic ethanol-treated rats. Propionate was also detected in livers 6 hours after treatment with carbon tetrachloride. The assignments of the 1H NMR resonances in a spectrum of biological origin to these two metabolites have not been previously reported. Another unusual metabolite, 1,2-propanediol, was also observed in dramatically elevated levels in starved rats. The methyl groups for coenzyme A, propionate, and 1,2-propanediol have 1H NMR chemical shifts at 0.73 and 0.87 ppm, 1.18 ppm, and 1.14 ppm (from tetramethylsilane) respectively. In addition to the above mentioned resonances, glutamine, glutamate, proline, acetate, leucine, alanine, lactate, ethanol, beta-hydroxybutyrate, and valine were also observed in the 0.5-2.3 ppm methyl region of the 1H NMR spectra. Biochemical changes were also observed in these latter metabolites. beta-Hydroxybutyrate was increased by chronic ethanol administration; this increase was exacerbated by starvation. Alanine was decreased by chronic ethanol administration. Acetate was increased by chronic ethanol administration except when glycerol was added to the liver or when the rat was starved. We also observed an unassigned triplet at 0.81 ppm, and its appearance seems to be correlated with that of 1,2-propanediol.

Amino Acids↗
PubMed1976

Vinyl chloride dependent mutagensis: effects of liver extracts and free radicals.

The mutagenic effects of vinyl chloride (VC) on Salmonella typhimurium strain TA1530 are enhanced by mouse or rat liver extracts. The extracts prepared from mice pretreated either with vinyl chloride or the microsomal enzyme inducer, Aroclor 1254, did not produce any greater stimulation of VC-dependent mutagenesis than extracts from untreated animals. These same extracts, however, differed markedly in their capacity to stimulate the mutagenicity of dimethylnitrosamine (DMN), a compound which is converted to a mutagen by an NADPH dependent microsomal mixed function oxidase. The order of activity of the extracts with DMN was Aroclor pretreated is greater than untreated is greater than VC pretreated. Furthermore, the stimulatory effect of the liver extracts on VC mediated mutagenesis did not require NADPH and was still evident in liver extracts in which the microsomal mixed function oxidase system had been heat inactivated. The mutagenic activity of VC also was found to be stimulated by riboflavin in the presence of light suggesting that free radicals may be involved in VC dependent mutagenesis.

Aroclors↗
PubMed1976

The exchange of erythrocyte membrane phospholipids with rat liver extracts in vitro.

Intact rat or human erythrocytes and their isolated (ghost) membranes were incubated with the high speed supernatant fraction of homogenates derived from 32P-labeled rat livers. Phospholipid molecules were transferred between the red cell membranes and the liver extracts, as reflected by the convergence of their specific radioactivities with time. Whereas ghosts usually approached isotopic equilibrium with the liver supernatant fraction during a few hours of incubation at 37 degrees C, the exchange of phospholipids by intact cells was no more than one-half, even after 18 hr. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and sphingomyelin were all exchanged in both intact cells and ghosts, albeit to different extents. (A control experiment, incubating 32P-labeled rat erythrocytes or ghosts with unlabeled rat liver extracts, also demonstrated the exchange of all four major phospholipids.) These data may signify that the phospholipids on the cytoplasmic side of the membrane of intact erythrocytes do not exchange with the phospholipids in exogenous liver extracts. If so, all four major phospholipid classes would appear to be present to some extent at both membrane surfaces. The first inference is in agreement with several other studies on this membrane, while the second inference is not.

Animals↗
PubMed1991

Action of plasma and liver extract from adult mice on the mitotic activity of young mouse liver.

Inbred C3HS male mice, standardized for periodicity analysis were used. A hundred and seventy 25 +/- 2 days old mice were injected at 16:00 hs with saline, plasma or liver extract from 27 mice 90 days old. Controls were made at 08/16, 12/20, 16/24, 08/40, 12/44, 16/48, 08/64, 12/68 and 16/72 (time of day/time post-injection). The mitotic activity of the hepatocytes and litoral cells were determined. The injection of small doses of extract and plasma inhibits the mitotic activity of hepatocytes during the first and second following days. A compensatory wave appears in the third day. The extract inhibits the mitotic activity of litoral cells in the first day of control only, whereas the plasma inhibits this variable in the second and third day.

Animals↗
PubMed1976

Naturally occurring immunosuppressive agents. II. The ability of cell-free liver extracts to modify the rejection of allogeneic skin grafts in the rabbit.

It has been demonstrated that cell-free extracts of pig, rabbit and human liver, but not of other parenchymal organs, contain a factor or factors capable of suppressing the proliferative responses of allogeneic and xenogeneic lymphoid cells stimulated with PHA, PWM, Con-A and allogeneic lymphocytes. Intravenous injection of the liver extract is capable of modifying significantly the skin allograft rejection reaction in normal adult outbred rabbits. Work is now in progress to isolate this factor and to determine its composition.

Animals↗
PubMed1978

[Cytological and cytochemical effects of a liver extract from an adult rat on chick embryo hepatocytes and fibroblasts cultivated in vitro].

The effects of an extract from adult liver on chick embryo hepatocytes and fibroblasts cultivated in vitro are studied with cytological and quantitative cytochemical methods. This substance inhibits the multiplication of hepatocytes adn prevents these cells from entering into the S phase of the cycle. No effect is observed on the chick embryo fibroblasts. Not any morphological alterations are observed in the two cell types.

Animals↗
PubMed1978

Hepatic activity in the generation of somatomedins: effects of administration of a liver extract.

The problem of the generation of growth factors (somatomedins) (SM) is at present a matter of investigation. The liver has been proposed as the primary site of production of SM. In order to verify this hypothesis, SM activity has been assayed in patients with impairment of liver function. The subjects have been divided into three groups according to the severity of the hepatic damage, assessed with conventional diagnostic tests. In every group, somatomedin A (ASM) has been assayed by means of a biological procedure, in basal conditions and after treatment with a liver extract. The results show that the ASM activity is reduced in proportion to the degree of hepatic damage. The administration of liver extract restores the production of the ASM in the first two groups of patients, i.e. in those with mild and moderate hepatic involvement.

Humans↗