scholarly journals Acinar zonation of cytosolic but not organelle-bound activities of phosphoenolpyruvate carboxykinase and aspartate aminotransferase in guinea-pig liver

1990 ◽  
Vol 271 (2) ◽  
pp. 387-391 ◽  
Author(s):  
L Agius ◽  
D Tosh
Keyword(s):  
Enzyme Activity ◽  
Guinea Pig ◽  
Aspartate Aminotransferase ◽  
Human Liver ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Cell Populations ◽  
Similar Distribution ◽  
Subcellular Compartment ◽  
Whole Cells ◽  
Intracellular Compartmentation

In human liver, unlike in rat liver, there is no apparent acinar heterogeneity of total cellular activity of phosphoenolpyruvate carboxykinase [Wimmer, Luttringer & Columbi (1990) Histochemistry 93, 409-415]. Since the intracellular compartmentation of phosphoenolpyruvate carbonxykinase differs in rat and human liver, we examined the acinar heterogeneity of cytosolic and organelle-bound activities of this enzyme in the guinea pig, which shows a more similar intracellular compartmentation of enzyme activity to human liver than does the rat. Cytosolic phosphoenolpyruvate carboxykinase activity was higher in periportal than in perivenous hepatocytes, whereas the organelle-bound activity was similar in the two cell populations. Aspartate aminotransferase and alanine aminotransferase activities showed a similar distribution to phosphoenolpyruvate carboxykinase, with a higher cytosolic activity in periportal than in perivenous hepatocytes but a similar organelle-bound activity in the two cell populations. Data on the acinar zonation of enzymes determined in whole cells or tissue should be interpreted cautiously if the enzyme activity is present in more than one subcellular compartment.

scholarly journals The effects of starvation and experimental diabetes on phosphoenol-pyruvate carboxykinase in the guinea pig

1977 ◽  
Vol 164 (2) ◽  
pp. 357-361 ◽  
Author(s):  
K R F Elliott ◽  
C I Pogson
Keyword(s):  
Enzyme Activity ◽  
Guinea Pig ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Blood Glucose Concentration ◽  
Mitochondrial Fraction ◽  
Kidney Cortex ◽  
Total Enzyme Activity ◽  
The Mean ◽  
Mean Blood Glucose ◽  
Total Enzyme

1. Approx. 85% of liver phosphoenolpyruvate carboxykinase is associated with the mitochondrial fraction in the fed guinea pig. Enzyme activity is unchanged in diabetes, but doubles during starvation. In contrast with earlier reports, both cytoplasmic and mitochondrial activities were found to be increased. 2. In kidney cortex, total enzyme activity is increased in both starved and diabetic animals. These changes are associated with increases in the cytoplasmic activity alone. 3. In diabetic animals the mean blood-glucose concentration was 23.1 mM. Other blood metabolites were lower than those in the rat, and the animals did not show significant ketosis. 4. Changes in the rates of gluconeogenesis from lactate and propionate paralleled those in phosphoenolpyruvate carboxykinase activity.

scholarly journals The distribution of enzyme and isoenzyme activities between parenchymal and haematopoietic cells in the liver of the foetal guinea pig

1979 ◽  
Vol 178 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Anne Faulkner ◽  
Colin T. Jones
Keyword(s):  
Enzyme Activity ◽  
Guinea Pig ◽  
Pyruvate Kinase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Liver Volume ◽  
Phosphoglycerate Mutase ◽  
Total Enzyme Activity ◽  
Haematopoietic Cells ◽  
Haematopoietic Cell ◽  
Pyruvate Kinase Isoenzymes

The hepatocyte and haematopoietic cell contents of the liver of the foetal guinea pig were measured over the latter half of gestation. Hepatocytes represented about 30% of liver volume at mid-gestation and this increased to 70–80% by term; cell volume remained fairly constant until 5–7 days before term, then more than doubled. Haematopoietic cells represented about 5% of liver volume at mid-gestation and this progressively fell to <1% by term. At 75% of gestation hepatocytes and haematopoietic cells were prepared from perfused foetal livers by collagenase digestion. Enzyme activity of the hepatocyte was, without exception, similar to that of the whole liver. In general, enzyme activity in the haematopoietic cells was similar to that in erythrocytes, with relatively low values for aldolase, glycerol 3-phosphate dehydrogenase, phosphoglycerate mutase, enolase, lactate dehydrogenase, phosphoenolpyruvate carboxykinase, fructose 1,6-bisphosphatase, isocitrate dehydrogenase, ‘malic’ enzyme, glutamate dehydrogenase and aspartate aminotransferase. The haematopoietic cell contribution to total enzyme activity in the foetal liver was usually much less than 10% and could thus not account for the major changes in hepatic enzyme activity over the latter half of gestation. Hepatocytes contained hexokinase isoenzymes I and III, aldolase isoenzymes A and B and pyruvate kinase isoenzymes 1, 2 and 4. The haematopoietic cells contained hexokinase isoenzyme I and two additional bands of activity with slightly greater mobility, aldolase isoenzyme A and pyruvate kinase isoenzymes 2 and 4.

scholarly journals Lipogenesis in rat and guinea-pig isolated epididymal fat-cells

1974 ◽  
Vol 140 (2) ◽  
pp. 211-224 ◽  
Author(s):  
E. David Saggerson
Keyword(s):  
Fatty Acids ◽  
Guinea Pig ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Aspartate Aminotransferase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Fat Cells ◽  
Hexose Monophosphate ◽  
Hexose Monophosphate Pathway ◽  
Rat Fat Cells

Fat-cells were prepared from rat and guinea-pig epididymal adipose tissue and compared on the basis of the intracellular distributions and activities of enzymes and with respect to their utilization of various U-14C-labelled substrates for lipogenesis. 1. Compared with the rat, guinea-pig extramitochondrial enzyme activities differed in that aconitate hydratase, alanine aminotransferase, ATP–citrate lyase, lactate dehydrogenase, NAD–malate dehydrogenase, NADP–malate dehydrogenase and phosphoenolpyruvate carboxykinase activities were appreciably lower, whereas aspartate aminotransferase, glucose 6-phosphate dehydrogenase, NADP–isocitrate dehydrogenase and 6-phosphogluconate dehydrogenase activities were appreciably higher. Mitochondrial activities of citrate synthase, NADP–isocitrate dehydrogenase and pyruvate carboxylase were appreciably lower, whereas mitochondrial activities of aspartate aminotransferase, glutamate dehydrogenase, NAD–malate dehydrogenase and phosphoenolpyruvate carboxykinase were higher in the guinea pig compared with the rat. 2. In general guinea-pig fat-cells incorporated acetate and lactate into fatty acids more readily than rat fat-cells, whereas rat fat-cells incorporated glucose and pyruvate more readily than guinea-pig fat-cells. 3. Acetate stimulated the incorporation of glucose into fatty acids in rat fat-cells, but had no appreciable effect upon this process in guinea-pig fat-cells. Acetate greatly decreased the incorporation of lactate into fatty acids in cells from both species. 4. Lactate/pyruvate ratios produced by incubation of guinea-pig cells with glucose+insulin were very low compared with those found with rat cells under the same conditions. 5. With glucose (+insulin) or with glucose+acetate (+insulin) as substrates guinea-pig cells produced enough NADPH by the hexose monophosphate pathway to satisfy the NADPH requirements of lipogenesis. In rat fat-cells under the same conditions, hexose monophosphate-pathway NADPH provision was not sufficient to meet the requirements of lipogenesis. 6. These results are discussed, particularly in relationship to the disposition of cytosolic reducing equivalents in the cells.

scholarly journals Single Cell, Single Nucleus and Spatial RNA Sequencing of the Human Liver Identifies Hepatic Stellate Cell and Cholangiocyte Heterogeneity

2021 ◽  
Author(s):  
Tallulah S Andrews ◽  
Jawairia Atif ◽  
Jeff C Liu ◽  
Catia T Perciani ◽  
Xue-Zhong Ma ◽  
...  
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
Human Liver ◽  
Stellate Cell ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Cell Populations ◽  
Healthy Human ◽  
Single Nucleus

The critical functions of the human liver are coordinated through the interactions of hepatic parenchymal and non-parenchymal cells. Recent advances in single cell transcriptional approaches have enabled an examination of the human liver with unprecedented resolution. However, dissociation related cell perturbation can limit the ability to fully capture the human liver's parenchymal cell fraction, which limits the ability to comprehensively profile this organ. Here, we report the transcriptional landscape of 73,295 cells from the human liver using matched single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq). The addition of snRNA-seq enabled the characterization of interzonal hepatocytes at single-cell resolution, revealed the presence of rare subtypes of hepatic stellate cells previously only seen in disease, and detection of cholangiocyte progenitors that had only been observed during in vitro differentiation experiments. However, T and B lymphocytes and NK cells were only distinguishable using scRNA-seq, highlighting the importance of applying both technologies to obtain a complete map of tissue-resident cell-types. We validated the distinct spatial distribution of the hepatocyte, cholangiocyte and stellate cell populations by an independent spatial transcriptomics dataset and immunohistochemistry. Our study provides a systematic comparison of the transcriptomes captured by scRNA-seq and snRNA-seq and delivers a high-resolution map of the parenchymal cell populations in the healthy human liver.

scholarly journals Analysis of enzyme activity and the level of malondialdehyde in the saliva of children with gingivitis

2009 ◽  
Vol 66 (11) ◽  
pp. 892-896
Author(s):  
Olivera Trickovic-Janjic ◽  
Tatjana Cvetkovic ◽  
Mirjana Apostolovic ◽  
Draginja Kojovic ◽  
Ljiljana Kostadinovic ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Aspartate Aminotransferase ◽  
Alanine Aminotransferase ◽  
Study Groups ◽  
Functional Condition ◽  
Gamma Glutamyl Transferase ◽  
Gamma Glutamyl ◽  
Severe Inflammation ◽  
Glutamyl Transferase

Introduction/Aim. By analyzing activity of some of the enzymes normally present in the saliva and the level of malondialdehyde in gingivitis, it is possible to estimate the functional condition of parodontium, and the examined parameters can be considered as biochemical markers of its functional condition. The aim of this paper was to examine activity of alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase and the level of malondialdehyde in the saliva of children affected with gingivitis, as well as the values of the mentioned parameters in relation to the level of the inflammation of gingiva. Methods. The research included 120 children at the age of 12.2 with permanent dentition. L?e and Silness gingival index was used to estimate the condition of gingiva, based on which the children were classified into four groups: the children with healthy gingiva (the control groups), the children with mild, moderate and severe inflammation of gingiva (the study group). Enzymes of the saliva were determined by the use of original tests and measured by the autoanalyser (Bio Systems A25, Spain). A modified method with tiobarbituric acid was used to determine malondialdehyde in nonstimulated mixed saliva. Results. The results of the examined enzyme activity and the level of malondialdehyde in the saliva of the study groups showed statistically considerably higher values for the level of malondialdehyde (p < 0.001), for the activity of aspartate aminotransferase and gamma glutamyl transferase (p < 0.01), as well as for alanine aminotransferase (p < 0.05) in comparison with the control group, whereas the activity of lactate dehydrogenase did not show a statistically significant increase. In relation to the level of the inflammation of gingiva, the results of the examination of the enzyme activity in the study groups showed statistically significantly higher values in the group with severe inflammation in comparison with those with mild, as well as the moderate inflammatory, except for the gamma glutamyl transferase, and in the group with moderate inflammation compared to that with the mild one, except for alanine aminotransferase. The results of the examination of the level of malondialdehyde in the saliva of the study groups did not show a statistically significantly increase in relation to the level of the inflammation of gingiva. Conclusion. There is a higher level of alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase and lactate dehydrogenase enzyme activity together with the higher level of malondialdehyde in the saliva of children with gingivitis in comparison with the activity of the same enzymes and the level of malondialdehyde in the saliva of children without gingivitis. The activity of the examined enzymes in the saliva of children with gingivitis increases in relation to the intensity of the pathological process, whereas the level of malondialdehyde shows no significant difference in relation to the level of the inflammation of gingiva.

The effects of ethanol (0.75 g/kg body weight) on the activities of selected enzymes in sera of healthy young adults: 1. Intermediate-term effects.

1977 ◽  
Vol 23 (5) ◽  
pp. 830-834 ◽  
Author(s):  
D E Freer ◽  
B E Statland
Keyword(s):  
Young Adults ◽  
Body Weight ◽  
Enzyme Activity ◽  
Aspartate Aminotransferase ◽  
Alanine Aminotransferase ◽  
Ethanol Ingestion ◽  
Similar Time ◽  
Gamma Glutamyltransferase ◽  
Time Courses ◽  
Apparently Healthy

Abstract We report the intermediate-term effects of three consecutive evenings of moderate ethanol ingestion (0.75 g/kg body weight each evening) on activity values for alkaline phosphatase, gamma-glutamyltransferase, creatine kinase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in sera of nine apparently healthy young adults. We define "intermediate-term" effects as those occurring between 10 h and 100 h after completion of the ethanol consumption schedule. The most pronounced changes in enzyme activity for the group of volunteers were: gamma-glutamyltransferase, +25% at 60 h after ethanol ingestion; alanine aminotransferase, +12% at 60 h after ethanol; and aspartate aminotransferase,--12% at 60 h after ethanol. All three enzymes exhibited similar time courses, i.e., mean peak activity changes were observed at 60 h, and all three mean enzyme activity values returned to near baseline by 100 h. The possible explanations for the observed changes and the clinical significance are discussed.

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