scholarly journals The effects of acute ethanol feeding and of chronic benfluorex administration on the activities of some enzymes of glycerolipid synthesis in rat liver and adipose tissue

1977 ◽  
Vol 166 (3) ◽  
pp. 639-642 ◽  
Author(s):  
P H Pritchard ◽  
M Bowley ◽  
S L Burditt ◽  
J Cooling ◽  
H P Glenny ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Rat Liver ◽  
Energy Content ◽  
Phosphatidate Phosphohydrolase ◽  
Acute Ethanol ◽  
Ethanol Feeding ◽  
Glycerolipid Synthesis

Rats were treated for 5 days with benfluorex [1-(3-trifluoromethylphenyl)-2-[N-(2-benzoyloxyethyl)amino]propane] or with suspending medium (controls). They were then intubated with an acute intoxicating dose of ethanol or with glucose of equivalent energy content. Treatment of the control rats with ethanol specifically increases the hepatic activity of the soluble phosphatidate phosphohydrolase by about 5-fold in 6 h. The equivalent increase for the benfluorex-treated rats were about 2-fold. The results are discussed in relation to the effects of ethanol and benfluorex on glycerolipid synthesis.

scholarly journals The effect of chronic diabetes, induced by streptozotocin, on the activities of some enzymes of glycerolipid synthesis in rat liver

1977 ◽  
Vol 168 (2) ◽  
pp. 147-153 ◽  
Author(s):  
P H Whiting ◽  
M Bowley ◽  
R G Sturton ◽  
P H Pritchard ◽  
D N Brindley ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Single Dose ◽  
Rat Liver ◽  
Diacylglycerol Acyltransferase ◽  
Diabetic Rats ◽  
Glycerol Phosphate ◽  
Choline Phosphotransferase ◽  
Phosphatidate Phosphohydrolase ◽  
Glycerolipid Synthesis ◽  
Increased Activity

1. Rats were injected with a single dose of 35mg of streptozotocin/kg body wt. They exhibited a diabetes that was characterized by glycosuria, polyuria, polydipsia, hyperphagia, hyperglycaemia, increased concentrations of unesterified fatty acids, glycerol and triacylglycerols in the serum and an increased activity of glucose 6-phosphatase in the liver. 2. After 10 weeks the hepatic activities of the microsomal glycerol phosphate acyltransferase, phosphatidate phosphohydrolase, phosphatidate cytidylyltransferase, diacylglycerol acyltransferase, choline phosphotransferase, CDP-diacylglycerolx—inositol phosphatidyltransferase and the soluble phosphatidate phosphohydrolase were measured. 3. The only significant changes were an increase in the activity of the soluble phosphatidate phosphohydrolase and a decrease in that of the CDP-diacylglycerol—inositol phosphatidyltransferase in the diabetic rats. 4. These results are discussed in relation to the control of glycerolipid synthesis.

scholarly journals Drugs affecting the synthesis of glycerides and phospholipids in rat liver. The effects of clofibrate, halofenate, fenfluramine, amphetamine, cinchocaine, chlorpromazine, demethylimipramine, mepyramine and some of their derivatives

1975 ◽  
Vol 148 (3) ◽  
pp. 461-469 ◽  
Author(s):  
D N Brindley ◽  
M Bowley
Keyword(s):  
Rat Liver ◽  
Inhibitory Effect ◽  
Diacylglycerol Acyltransferase ◽  
Major Effect ◽  
Glycerol Phosphate ◽  
Liver Slices ◽  
Phosphatidate Phosphohydrolase ◽  
Marked Accumulation ◽  
Glycerolipid Synthesis ◽  
Phosphatidylcholine Synthesis

The effects on glycerolipid synthesis of a series of compounds including many drugs were investigated in cell-free preparations and slices of rat liver. p-Chlorobenzoate, p-chlorophenoxyisobutyrate, halofenate, D-amphetamine, adrenaline, procaine and N-[2-(4-chloro-3-sulphamoylbenzoyloxy)ethyl]norfenfluramine had little inhibitory effect on any of the systems investigated. Two amphiphilic anions, clofenapate and 2-(p-chlorophenyl)-2-(m-trifluoromethylphenoxy)acetate, both inhibited glycerol phosphate acyltransferase and diacylglycerol acyltransferase at approx. 1.6 and 0.7 mm respectively. Clofenapate (1 mm) also inhibited the incorporation of glycerol into lipids by rat liver slices without altering the relative proportions of the different lipids synthesized. The amphilic amines, mepyramine, fenfluramine, norfenfluramine, hydroxyethylnorfenfluramine, N-(2-benzoyloxyethyl)norfenfluramine, cinchocaine, chlorpromazine and demethylimipramine inhibited phosphatidate phosphohydrolase by 50% at concentrations between 0.2 and 0.9 mm. The last four compounds inhibited glycerol phosphate acyltransferase by 50% at concentrations between 1 and 2.6 mm. None of the amines examined appeared to be an effective inhibitor of diacylglycerol acyltransferase. Norfenfluramine, hydroxyethylnorfenfluramine and N-(2-benzoyloxyethyl)norfenfluramine produced less inhibition of glycerol incorporation into total lipids than was observed with equimolar clofenapate. The major effect of these amines in liver slices was to inhibit triacylglycerol and phosphatidylcholine synthesis and to produce a marked accumulation of phosphatidate. The results are discussed in terms of the control of glycerolipid synthesis. They partly explain the observed effects of the various drugs on lipid metabolism. The possible use of these compounds as biochemical tools with which to investigate the reactions of glycerolipid synthesis is considered.

scholarly journals Glutathione recycling is attenuated by acute ethanol feeding in rat liver

1997 ◽  
Vol 12 (4) ◽  
pp. 316 ◽  
Author(s):  
S I Oh ◽  
C I Kim ◽  
H J Chun ◽  
M S Lee ◽  
S C Park
Keyword(s):  
Rat Liver ◽  
Acute Ethanol ◽  
Ethanol Feeding

scholarly journals The effects of amphiphilic cationic drugs and inorganic cations on the activity of phosphatidate phosphohydrolase

1977 ◽  
Vol 165 (3) ◽  
pp. 447-454 ◽  
Author(s):  
M Bowley ◽  
J Cooling ◽  
S L Burditt ◽  
D N Brindley
Keyword(s):  
Physical Properties ◽  
Rat Liver ◽  
Partition Coefficients ◽  
Inorganic Cations ◽  
Cationic Drugs ◽  
Phosphatidate Phosphohydrolase ◽  
Glycerolipid Synthesis

1. Phosphatidate phosphohydrolase from the particle-free supernatant of rat liver was assayed by using emulsions of phosphatidate as substrate. 2. The inhibition of the phosphohydrolase by chlorpromazine was of a competitive type with respect to phosphatidate. The potency of various amphiphilic cationic drugs as inhibitors of this reaction was related to their partition coefficients into a phosphatidate emulsion. 3. The effect of chlorpromazine on the phosphohydrolase activity was complementary rather than antagonistic towards Mg2+. Chlorpromazine stimulated the phosphohydrolase activity in the absence of added Mg2+ and was able to replace the requirement for Mg2+. However, at optimum concentrations of Mg2+, chlorpromazine inhibited the reaction, as did Ca2+. The phosphohydrolase activity was also stimulated by Co2+ and to a lesser extent by Mn2+, Fe2+, Fe3+, Ca2+, spermine and spermidine when Mg2+ was not added to the assays. 4. It is concluded that the inhibition of phosphatidate phosphohydrolase by amphiphilic cations can largely be explained by the interaction of these compounds with phosphatidate, which changes the physical properties of the lipid, making it less available for conversion into diacylglycerol. 5. The implications of these results to the effects of amphiphilic cations in redirecting glycerolipid synthesis at the level of phosphatidate are discussed.

Effects of starvation, corticotropin injection and ethanol feeding on the activity and amount of phosphatidate phosphohydrolase in rat liver

FEBS Letters ◽  
1981 ◽  
Vol 126 (2) ◽  
pp. 297-300 ◽  
Author(s):  
R.Graham Sturton ◽  
Simon C. Butterwith ◽  
Susan L. Burditt ◽  
David N. Brindley
Keyword(s):  
Rat Liver ◽  
Phosphatidate Phosphohydrolase ◽  
Ethanol Feeding

scholarly journals Oxidative phosphorylation. The specific binding of trimethyltin and triethyltin to rat liver mitochondria

1970 ◽  
Vol 118 (1) ◽  
pp. 171-179 ◽  
Author(s):  
W. N. Aldridge ◽  
B. W. Street
Keyword(s):  
Adipose Tissue ◽  
Oxidative Phosphorylation ◽  
Brown Adipose Tissue ◽  
Binding Site ◽  
Rat Liver ◽  
Specific Binding ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Affinity Constants ◽  
Brown Adipose

1. The binding of trimethyltin and triethyltin to rat liver mitochondria was determined and the results were analysed by the method of Scatchard (1949). 2. One binding site (site 1) has the correct characteristics for the site to which trimethyltin and triethyltin are attached when they inhibit oxidative phosphorylation. For each compound the concentration of site 1 is 0.8nmol/mg of protein and the ratios of their affinity constants are the same as the ratio of the concentrations inhibiting oxidative phosphorylation. 3. Binding site 1 is present in a fraction derived from mitochondria containing only 15% of the original protein. In this preparation ultrasonication rapidly destroyed site 1. 4. Dimethyltin and diethyltin do not prevent binding of triethyltin to rat liver mitochondria, whereas triethyl-lead does. 5. Trimethyltin and triethyltin bind to mitochondria from brown adipose tissue and the results indicate a binding site 1 similar to that in rat liver mitochondria. 6. The advantages and limitations of this approach to the study of inhibitors are discussed.

Effect of Chronic Ethanol Feeding on Oxysterols in Rat Liver

2002 ◽  
Vol 36 (6) ◽  
pp. 661-666 ◽  
Author(s):  
Koichi Ariyoshi ◽  
Junko Adachi ◽  
Migiwa Asano ◽  
Yasuhiro Ueno ◽  
Rajkumar Rajendram ◽  
...  
Keyword(s):  
Rat Liver ◽  
Chronic Ethanol ◽  
Ethanol Feeding

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.

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