scholarly journals Lipid metabolism by rat lung in vitro. Effect of starvation and re-feeding on utilization of [U-14C]glucose by lung slices

1971 ◽  
Vol 124 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Richard W. Scholz ◽  
Rodney A. Rhoades
Keyword(s):  
Fatty Acid ◽  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Total Phospholipid ◽  
Fatty Acid Fraction ◽  
Acid Fraction ◽  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Vitro Effect

1. The incorporation of [U-14C]glucose into several lipid components of lung and liver slices, and the activities of glucose 6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 1.1.1.44), ‘malic’ enzyme (EC 1.1.1.40) and NADP–isocitrate dehydrogenase (EC 1.1.1.42) of the cell cytosol were examined in normal, starved and re-fed rats. 2. Lipogenesis and the activities of these enzymes in liver were decreased markedly in rats starved for 72h. Re-feeding starved rats on a fat-free diet for 72h resulted in the well documented hyperlipogenic response in liver, particularly in its ability to convert glucose into neutral lipid, and increased activities of glucose 6-phosphate dehydrogenase, ‘malic’ enzyme and 6-phosphogluconate dehydrogenase to values approx. 700, 470 and 250% of controls respectively. 3. Approx. 70% of the total label in lung lipids was present in the phospholipid fraction. Hydrolysis of lung phospholipids revealed that lipogenesis from glucose was considerable, with approx. 40% of the total phospholipid radioactivity present in the fatty acid fraction. 4. Incorporation of glucose into total lung lipids was decreased by approx. 40% in lung slices of starved rats and was returned to control values on re-feeding. Although phospholipid synthesis from glucose was decreased in lung slices of starved rats, the decrease proportionally was greater for the fatty acid fraction (approx. 50%) as compared with the glycerol fraction (approx. 25%). 5. The activities of lung glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and NADP–isocitrate dehydrogenase were not affected by the dietary alterations. ‘Malic’ enzyme activity was not detected in lung cytosol preparations. 6. The results are discussed in relation to the surface-active lining layer (surfactant) of the lung.

NADP-linked dehydrogenases in secreted milk

1985 ◽  
Vol 52 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Murray R. Grigor ◽  
Peter E. Hartmann
Keyword(s):  
Mammary Gland ◽  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Prolonged Storage ◽  
Phosphogluconate Dehydrogenase ◽  
The Absolute ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Accurate Reflection

SUMMARYThe activities of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase, malic enzyme, lactate dehydrogenase and malate dehydrogenase have been determined in secreted milk from sows, rats and rabbits. Within each species, although there was considerable variation in the absolute activities of these enzymes, the relative activities were similar to those observed for, or previously published for mammary homogenates. The only exception was milk glucose 6-phosphate dehydrogenase which tended to lose activity upon prolonged storage in the mammary gland. These results suggest that the pattern of milk enzymes can be an accurate reflection of that occurring in the mammary gland.

scholarly journals Enzymes of glucose metabolism in normal mouse pancreatic islets

1970 ◽  
Vol 119 (1) ◽  
pp. 5-15 ◽  
Author(s):  
S. J. H. Ashcroft ◽  
P. J. Randle
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Pyruvate Carboxylase ◽  
Normal Mouse ◽  
Mean Value ◽  
Intact Mouse ◽  
Major Activity ◽  
Phosphogluconate Dehydrogenase ◽  
Total Glucose ◽  
Glucose 6 Phosphate Dehydrogenase

1. Glucose-phosphorylating and glucose 6-phosphatase activities, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, NADP+-linked isocitrate dehydrogenase, `malic' enzyme and pyruvate carboxylase were assayed in homogenates of normal mouse islets. 2. Two glucose-phosphorylating activities were detected; the major activity had Km 0.075mm for glucose and was inhibited by glucose 6-phosphate (non-competitive with glucose) and mannoheptulose (competitive with glucose). The other (minor) activity had a high Km for glucose (mean value 16mm) and was apparently not inhibited by glucose 6-phosphate. 3. Glucose 6-phosphatase activity was present in amounts comparable with the total glucose-phosphorylating activity, with Km 1mm for glucose 6-phosphate. Glucose was an inhibitor and the inhibition showed mixed kinetics. No inhibition of glucose 6-phosphate hydrolysis was observed with mannose, citrate or tolbutamide. The inhibition by glucose was not reversed by mannoheptulose. 4. 6-Phosphogluconate dehydrogenase had Km values of 2.5 and 21μm for NADP+ and 6-phosphogluconate respectively. 5. Glucose 6-phosphate dehydrogenase had Km values of 4 and 22μm for NADP+ and glucose 6-phosphate. The Km for glucose 6-phosphate was considerably below the intra-islet concentration of glucose 6-phosphate at physiological extracellular glucose concentrations. The enzyme had no apparent requirement for cations. Of a number of possible modifiers of glucose 6-phosphate dehydrogenase, only NADPH was inhibitory. The inhibition by NADPH was competitive with NADP+ and apparently mixed with respect to glucose 6-phosphate. 6. NADP+–isocitrate dehydrogenase was present but the islet homogenate contained little, if any, `malic' enzyme. The presence of pyruvate carboxylase was also demonstrated. 7. The results obtained are discussed with reference to glucose phosphorylation and glucose 6-phosphate oxidation in the intact mouse islet, and the possible nature of the β-cell glucoreceptor mechanism.

Estimations of Rates of Synthesis and Degradation of Several Rat Mammary Gland Enzymes from Changes in Enzyme Activities

1972 ◽  
Vol 50 (4) ◽  
pp. 386-391 ◽  
Author(s):  
G. O. Korsrud ◽  
R. L. Baldwin
Keyword(s):  
Fatty Acid ◽  
Malic Enzyme ◽  
Fatty Acid Synthetase ◽  
Mammary Glands ◽  
Phosphogluconate Dehydrogenase ◽  
Udpglucose Pyrophosphorylase ◽  
Cleavage Enzyme ◽  
Rat Mammary Gland ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Synthesis And Degradation

Based upon rates of decrease in the activities of citrate cleavage enzyme (EC 4.1.3.7), malic enzyme (EC 1.1.1.40), fatty acid synthetase, UDPglucose pyrophosphorylase (EC 2.7.7.9), UDPglucose 4-epimerase (EC 5.1.3.3), and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) in rat mammary glands after adrenalectomy–ovariectomy on the 11th day of lactation, the half-lives of the enzymes were estimated to be 28, 31, 28, 50, 20, and 24 h, respectively. The half-life estimates for UDPglucose pyrophosphorylase and glucose-6-phosphate dehydrogenase compared favorably with previous estimates of 35 and 20 h, respectively, obtained in rats 5 days postpartum utilizing specific immunological techniques. In a second experiment, increases in the activities of enzymes in adrenalectomized, lactating rats after initiation of cortisol therapy were investigated. Rats were adrenalectomized on the 5th day of lactation and cortisol therapy was started 5 days later. The estimated half-lives for citrate cleavage enzyme, malic enzyme, fatty acid synthetase, UDPglucose pyrophosphorylase, UDPglucose 4-epimerase, the A protein of the lactose synthetase complex, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase (EC 1.1.1.44), and hexokinase (EC 2.7.1.1) were, respectively, 84, 60, 92, 76, 170, 102, 79, 88, and 81 h.

scholarly journals GC-MS analysis and in vitro bioactivity of fixed oil and fatty acid fraction obtained from seeds of Simira gardneriana, a Rubiaceae from Brazilian Caatinga Biome

2016 ◽  
Vol 10 (23) ◽  
pp. 493-500
Author(s):  
Adrielly Alves Ferraz Christiane ◽  
Gon ccedil alves de Oliveira Raimundo ◽  
Martins de Lavor Eacute rica ◽  
Gama e Silva Mariana ◽  
Paula de Oliveira Ana ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Fraction ◽  
Acid Fraction ◽  
In Vitro Bioactivity ◽  
Ms Analysis ◽  
Caatinga Biome

scholarly journals NADP-Dependent Isocitrate Dehydrogenase fromArabidopsisRoots Contributes in the Mechanism of Defence against the Nitro-Oxidative Stress Induced by Salinity

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Marina Leterrier ◽  
Juan B. Barroso ◽  
Raquel Valderrama ◽  
José M. Palma ◽  
Francisco J. Corpas
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Superoxide Radical ◽  
Plant Defence ◽  
Maximum Activity ◽  
Nadph Regeneration ◽  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase

NADPH regeneration appears to be essential in the mechanism of plant defence against oxidative stress. Plants contain several NADPH-generating dehydrogenases including isocitrate dehydrogenase (NADP-ICDH), glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), and malic enzyme (ME). InArabidopsisseedlings grown under salinity conditions (100 mM NaCl) the analysis of physiological parameters, antioxidant enzymes (catalase and superoxide dismutase) and content of superoxide radical (O2  ∙−), nitric oxide (NO), and peroxynitrite (ONOO-) indicates a process of nitro-oxidative stress induced by NaCl. Among the analysed NADPH-generating dehydrogenases under salinity conditions, the NADP-ICDH showed the maximum activity mainly attributable to the root NADP-ICDH. Thus, these data provide new insights on the relevance of the NADP-ICDH which could be considered as a second barrier in the mechanism of response against the nitro-oxidative stress generated by salinity.

scholarly journals Development of NADPH-producing pathways in rat heart

1980 ◽  
Vol 186 (3) ◽  
pp. 799-803 ◽  
Author(s):  
A Andrés ◽  
J Satrústegui ◽  
A Machado
Keyword(s):  
Pentose Phosphate Pathway ◽  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Rat Heart ◽  
Pentose Phosphate ◽  
Mitochondrial Enzyme ◽  
Physiological Functions ◽  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Mitochondrial Malic Enzyme

The behaviours of the principal NADPH-producing enzymes (glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, cytoplasmic and mitochondrial ‘malic’ enzyme and NAPD+-dependent isocitrate dehydrogenase) were studied during the development of rat heart and compared with those in brain and liver. 1. The enzymes belonging to the pentose phosphate pathway exhibit lower activities in heart than in other tissues throughout development. 2. The pattern of induction of heart cytoplasmic and mitochondrial ‘malic’ enzymes does not parallel that found in liver. Heart mitochondrial enzyme is slowly induced from birth onwards. 3. NADP+-dependent isocitrate dehydrogenase has similar activities in all tissues in 18-day foetuses. 4. Heart mitochondrial NADP+-dependent isocitrate dehydrogenase is greatly induced in the adult, where it attains a 10-fold higher activity than in liver. 5. The physiological functions of mitochondrial ‘malic’ enzyme and NADP+-dependent isocitrate dehydrogenase are discussed.

scholarly journals AN UNSATURATED FATTY ACID FRACTION OF PIG PANCREAS WHICH INHIBITS THE GROWTH OF CHICKEN SARCOMA

1936 ◽  
Vol 64 (3) ◽  
pp. 333-338 ◽  
Author(s):  
O. M. Helmer
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Iodine Number ◽  
Aqueous Extract ◽  
Unsaturated Fatty Acid ◽  
Fatty Acid Fraction ◽  
Pancreatic Tissue ◽  
Acid Number ◽  
Acid Fraction ◽  
Commercial Oleic Acid

The inhibiting action of pancreatic tissue was found to be associated with the unsaturated fatty acid fraction. As small an amount of fatty acid as 0.1 mg. inhibited the chicken sarcoma agent contained in 0.2 cc. of a 1:60 aqueous extract of Chicken Tumor I. The unsaturated fatty acid had an acid number and an iodine number similar to those for oleic acid. Commercial oleic acid also was found to inhibit the growth of the chicken sarcoma in comparable quantities.

Effects of addition of clay minerals on the fatty acid fraction of a podzol soil

1995 ◽  
Vol 46 (2) ◽  
pp. 187-192 ◽  
Author(s):  
P. JAMBU ◽  
A. AMBLES ◽  
P. MAGNOUX ◽  
E. PARLANTI
Keyword(s):  
Fatty Acid ◽  
Clay Minerals ◽  
Fatty Acid Fraction ◽  
Acid Fraction
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