scholarly journals Increased liver l-serine–pyruvate aminotransferase activity under gluconeogenic conditions (Short Communication)

1973 ◽  
Vol 134 (1) ◽  
pp. 349-351 ◽  
Author(s):  
Edward V. Rowsell ◽  
Ali H. Al-Tai ◽  
John A. Carnie ◽  
Kathleen V. Rowsell
Keyword(s):  
Rat Liver ◽  
Short Communication ◽  
Neonatal Period ◽  
Normal Adult ◽  
Aminotransferase Activity ◽  
Serine Dehydratase ◽  
Glucagon Injection ◽  
Alloxan Injection

Rat liver l-serine–pyruvate aminotransferase activity exceeds markedly the normal adult value (a) in the neonatal period, (b) after glucagon injection and (c) after alloxan injection, observations that reinforce the suggestion from comparative findings that the aminotransferase has a role in gluconeogenesis. Some findings, however, argue in favour of l-serine dehydratase as the enzyme of gluconeogenesis from l-serine.

scholarly journals Carbohydrate formation from various precursors in neonatal rat liver

1968 ◽  
Vol 110 (4) ◽  
pp. 725-731 ◽  
Author(s):  
R. G. Vernon ◽  
Susan W. Eaton ◽  
D G Walker
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Neonatal Period ◽  
Casein Hydrolysate ◽  
Amino Acid Mixture ◽  
Neonatal Rat ◽  
Acid Mixture ◽  
Hepatic Gluconeogenesis ◽  
Threonine Dehydratase ◽  
Serine Dehydratase

1. Measurements of the net synthesis of glucose plus glycogen from various precursors in slices of glycogen-depleted livers from rats at various stages of development indicated an increase in the gluconeogenic capacity after birth with l-lactate, oxaloacetate, a casein hydrolysate, l-serine, l-threonine, l-alanine and glycerol as substrates. 2. The highest rates of incorporation of 14C-labelled precursors into glucose plus glycogen in slices of normal livers of rats of various ages were observed in such tissue preparations from neonatal animals for an amino acid mixture, l-alanine, l-serine and l-threonine. 3. The activities of rat hepatic l-serine dehydratase and l-threonine dehydratase increase rapidly after birth and show maxima about 20 days later. 4. The results provide further evidence of the increased capacity for hepatic gluconeogenesis in the neonatal period and suggest various sites of regulation of the process.

scholarly journals Subcellular distribution of pyruvate (glyoxylate) aminotransferases in rat liver

1978 ◽  
Vol 170 (1) ◽  
pp. 173-175 ◽  
Author(s):  
T Noguchi ◽  
Y Minatogawa ◽  
Y Takada ◽  
E Okuno ◽  
R Kido
Keyword(s):  
Rat Liver ◽  
Subcellular Distribution ◽  
Enzyme Activities ◽  
Particulate Fraction ◽  
Aminotransferase Activity ◽  
Liver Homogenates ◽  
Glucagon Injection ◽  
Glyoxylate Aminotransferase

The distribution of pyruvate (glyoxylate) aminotransferases in the particulate fraction of rat liver homogenates was examined by centrifugation in a sucrose density graident. Aminotransferase activities towards serine, phenylalanine and histidine with pyruvate and those towards phenylalanine and histidine with glyoxylate were nearly identically distributed. Some 50-55% of the particulate activity was localized in the peroxisomes and the remainder in the mitochondria. Most of alanine-glyoxylate aminotransferase activity was localized in the mitochondria, with some activity in the peroxisomes. Glucagon injection resulted in increases of these enzyme activities in the mitochondria, but not in the peroxisomes.

scholarly journals Aldehyde dehydrogenase in 2-acetaminofluorene-induced rat hepatomas. Ontogeny and evidence that the new isoenzymes are not due to normal gene de-repression

1977 ◽  
Vol 164 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Ronald Lindahl
Keyword(s):  
Rat Liver ◽  
Aldehyde Dehydrogenase ◽  
Double Diffusion ◽  
Normal Liver ◽  
Normal Adult ◽  
Sprague Dawley ◽  
Adult Liver ◽  
Aldehyde Dehydrogenases ◽  
Adult Rat ◽  
Liver Aldehyde Dehydrogenase

The pre- and post-natal ontogeny of Sprague–Dawley rat liver aldehyde dehydrogenase [aldehyde–NAD(P)+ oxidoreductase, EC 1.2.1.5] is described. At no time in its ontogenetic development does normal liver aldehyde dehydrogenase exhibit any of the characteristics of a series of unique aldehyde dehydrogenases that can be isolated from 2-acetamidofluorene-induced rat hepatomas. Enzyme activity is first detectable in 15-day foetal liver and gradually increases throughout pre- and post-natal development until adult activities are attained by day 49 after birth. Electrophoretically, normal aldehyde dehydrogenase, throughout its ontogeny, exists as the same single isoenzyme found in normal adult liver. Isoelectric points for two normal liver isoenzymes demonstrable by isoelectric focusing are pH5.9 and 6.0. The immunochemical properties of aldehyde dehydrogenase during its ontogeny are identical with those of normal adult liver aldehyde dehydrogenase when tested against anti-(hepatoma aldehyde dehydrogenase) serum in Ouchterlony double-diffusion tests. The results indicate that the hepatoma-specific aldehyde dehydrogenases are not the result of the de-repression of genes normally repressed in adult rat liver or in some other adult tissue.

scholarly journals Biphasic effect of acute ethanol administration on rat liver tyrosine-2-oxoglutarate aminotransferase activity

1980 ◽  
Vol 186 (3) ◽  
pp. 755-761 ◽  
Author(s):  
A A B Badawy ◽  
B M Snape ◽  
M Evans
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Actinomycin D ◽  
Tyrosine Aminotransferase ◽  
Ethanol Metabolism ◽  
Ethanol Administration ◽  
Aminotransferase Activity ◽  
Biphasic Effect ◽  
Initial Decrease ◽  
Acute Ethanol

1. Acute ethanol administration causes a biphasic change in rat liver tyrosine aminotransferase activity. 2. The initial decrease is significant with a 200 mg/kg dose of ethanol, is prevented by adrenoceptor-blocking agnets and by reserpine, but not by inhibitors of ethanol metabolism, and exhibits many of the characteristics of the inhibition caused by noradrenaline. 3. The subsequent enhancement of the enzyme activity by ethanol is not associated with stabilization of the enzyme, but is sensitive to actinomycin D and cycloheximide. 4. It is suggested that the initial decrease in aminotransferase activity is caused by the release of catecholamines, whereas the subsequent enhancement may be related to the release of glucocorticoids.

scholarly journals Contamination of free-ribosome fractions by detached previously membrane-bound ribosomes (Short Communication)

1974 ◽  
Vol 138 (2) ◽  
pp. 305-307 ◽  
Author(s):  
K. O'Toole
Keyword(s):  
Rat Liver ◽  
Membrane Fraction ◽  
Short Communication ◽  
Free Ribosome ◽  
Membrane Bound ◽  
Free Polyribosome

A rough-membrane fraction isolated from rat liver by a procedure designed to prevent membrane denaturation was subjected to the gradient treatment normally used to isolate free ribosomes. Under these conditions, at most 20% of the ribosomes were detached from membrane with less than 5% sedimenting into the free-polyribosome pellet.

The deamination of 5′-deoxycytidylic acid in normal adult rat liver and in DUNNING hepatoma

1961 ◽  
Vol 51 (1) ◽  
pp. 173-175 ◽  
Author(s):  
Eduardo Scarano ◽  
Massimo Talarico ◽  
Silvio Fiala
Keyword(s):  
Rat Liver ◽  
Normal Adult ◽  
Adult Rat

SHORT COMMUNICATION: Increasing the interval between initiation and the onset of exposure to orotic acid decreases its promoting effect on rat liver carcinogenesis

1993 ◽  
Vol 14 (8) ◽  
pp. 1701-1704 ◽  
Author(s):  
E. Laconi ◽  
S. Vasudevan ◽  
P.M. Rao ◽  
S. Rajalakshnii ◽  
P. Pani ◽  
...  
Keyword(s):  
Rat Liver ◽  
Orotic Acid ◽  
Short Communication ◽  
Liver Carcinogenesis ◽  
Promoting Effect
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