scholarly journals Malonate and Carrot Root Respiration

1952 ◽  
Vol 5 (1) ◽  
pp. 64 ◽  
Author(s):  
Vera F Hanly ◽  
KS Rowan ◽  
JS Turner
Keyword(s):  
Organic Acid ◽  
Root Respiration ◽  
Direct Evidence ◽  
Succinic Dehydrogenase ◽  
Low Ph ◽  
Ionic Exchange ◽  
Carrot Root ◽  
Fermentation Products ◽  
Acid Cycle ◽  
Enzyme Systems

Following a review of earlier work with malonate as an enzyme and respiration inhibitor, direct evidence is provided of the existence in carrot root tissue of cytochrome oxidase and succinic dehydrogenase (S.D.). Malonate is clearly effective as an inhibitor of carrot root respiration only at low pH. Its effects at higher pH are, however, fully described and discussed. It is postulated that in this tissue a significant part of the respiration is mediated by enzyme systems not inhibited by malonate, KCN, or CO; that the remainder, whose activity is varied by wounding and aging, and by ionic exchange and uptake, involves an organic acid cycle of the Krebs type. The effects at low pH and low concentration of malonate (O.005-0.02M) may be explained as due to inhibition of succinic dehydrogenase only; under these conditions self reversal of inhibition, and reversal by addition of succinate, are both possible. At higher concentrations ( O.04-0.05M ) and low pH, malonate is assumed to inhibit not only S.D. but other enzymes concerned in pyruvate oxidation; this explains the lack of self reversal, lack of reversal by added succinate, and the failure to demonstrate accumulation of succinate in poisoned tissue; under these conditions, when inhibition is to the basal level, the RQ. is high, presumably because pyruvate is diverted to form fermentation products.

Effect of mercuric chloride on some kidney enzymes in chow-fed and sucrose-fed rats

1960 ◽  
Vol 198 (1) ◽  
pp. 187-190 ◽  
Author(s):  
V. Shore ◽  
B. Shore
Keyword(s):  
Alkaline Phosphatase ◽  
Cytochrome Oxidase ◽  
Mercuric Chloride ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Enzyme Systems ◽  
Rat Kidneys ◽  
Ketoglutarate Dehydrogenase

Rats given a diet of sucrose and vitamins for 3 weeks or more develop a tolerance to mercuric chloride greater than that of chow-fed rats. Comparison of several enzyme systems (tricarboxylic acid cycle, succinic dehydrogenase, cytochrome oxidase, α-ketoglutarate dehydrogenase, alkaline phosphatase, cathepsins and ß-glucuronidase) in chow-fed and sucrose-fed rats indicated no significant differences in activities. After 3 mg HgCl2/kg i.v., notable differences in the extent of inhibition of tricarboxylic acid enzyme systems were observed. Twenty-four hours after such an injection, kidneys of chow-fed rats were seriously hampered in their ability to perform biological energy transformations. Oxidation and phosphorylation by sucrose-fed rat kidneys were considerably less inhibited.

EFFECT OF SERUM GONADOTROPHIN ON DEHYDROGENASES OF THE CITRIC ACID CYCLE IN THE OVARY OF THE RAT

1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Age Groups ◽  
Succinic Dehydrogenase ◽  
Immature Rat ◽  
Acid Cycle ◽  
Immature Rats ◽  
Rat Ovary

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.

scholarly journals Sol-Gel Processes in Micro-Environments of Black Shale: Learning from the Industrial Production of Nanometer-Sized TiO2 Polymorphs

2019 ◽  
Vol 3 (1) ◽  
pp. 28
Author(s):  
Hans-Martin Schulz
Keyword(s):  
Black Shale ◽  
Industrial Production ◽  
Sol Gel ◽  
Low Ph ◽  
Ionic Exchange ◽  
Geochemical Processes ◽  
Pore Waters ◽  
Surrounding Matrix ◽  
Geochemical Reactions ◽  
Bulk Scale

Micro-environments in black shale are reactors for geochemical reactions that differ from the bulk scale. They occur in small isolated pores of several 10 s to 100 s of nanometers without or with limited ionic exchange by diffusion to the surrounding matrix. The example of the formation of titania polymorphs brookite (and anatase) in black shale demonstrates that pH < 4 of the pore waters or lower must prevail to enable dissolution of Ti-bearing precursors followed by the precipitation of these metastable solids. Comparably low pH is applied during the industrial production of nanometer-sized brookite or anatase by sol-gel methods. The process parameters during industrial production such as low pH, negative Eh, or low ionic strength (to promote agglomeration) allow a comparison with parameters during geochemical processes leading to titania formation in black shale. Sol-gel processes are suggested herein as key geochemical processes in micro-environments of black shale in order to understand the formation of single brookite crystals or agglomerates on a nanometer scale.

STEROID METABOLISM OF A SERTOLI CELL TUMOUR OF THE TESTIS OF A DOG WITH FEMINIZATION AND ALOPECIA AND OF THE NORMAL CANINE TESTIS

1967 ◽  
Vol 38 (1) ◽  
pp. 61-NP ◽  
Author(s):  
C. G. PIERREPOINT ◽  
JEAN McI. GALLEY ◽  
K. GRIFFITHS ◽  
J. K. GRANT
Keyword(s):  
Sertoli Cell ◽  
Direct Evidence ◽  
Hydroxysteroid Dehydrogenase ◽  
Testicular Tissue ◽  
Cell Tumour ◽  
Tumour Tissue ◽  
Steroid Metabolism ◽  
Enzyme Systems ◽  
Sertoli Cell Tumour

SUMMARY The metabolism of [7α-3H]pregnenolone and [4-14C]dehydroepiandrosterone (DHA) by a Sertoli cell tumour of the testis from a dog with signs of feminization has been studied in vitro and compared with the metabolism of the normal canine testis. The tumour formed oestrone and oestradiol-17β from DHA thus providing direct evidence for the synthesis of oestrogen by this type of neoplasm. Relative or complete inactivity of several enzyme systems involved in the synthesis of testosterone was found in the tumour tissue, and the conversion of either precursor to testosterone was considerably less than in the normal testis. Suggestive evidence is presented for the occurrence of steroid-specific 17α-hydroxylase and 3β-hydroxysteroid dehydrogenase-isomerase systems in canine testicular tissue. The formation of sulphates of pregnenolone and DHA was shown both in normal and in neoplastic tissues and, in addition, the tumour either formed the sulphate of 17α-hydroxypregnenolone or caused the 17α-hydroxylation of pregnenolone sulphate.

scholarly journals IN VITRO EFFECTS OF FLUORIDE ON TRICARBOXYLIC ACID CYCLE DEHYDROGENASES AND OXIDATIVE PHOSPHORYLATION: PART I

1967 ◽  
Vol 15 (4) ◽  
pp. 195-201 ◽  
Author(s):  
C. JAMES LOVELACE ◽  
GENE W. MILLER
Keyword(s):  
Oxidative Phosphorylation ◽  
Competitive Inhibition ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Initial Increase ◽  
Acid Cycle ◽  
Oxidase System ◽  
Vitro Effect

Studies were conducted on the in vitro effect of fluoride on the succinic oxidase system utilizing mitochondria obtained from cauliflower. Preincubation of mitochondria with fluoride did not increase inhibition of succinic oxidase. Various other tricarboxylic acid cycle substrates were used to determine their sensitivity to fluoride; only succinate oxidation was affected. A series of succinate concentrations in the presence and in the absence of fluoride showed increased activity of succinic dehydrogenase, which indicated competitive inhibition. Various concentrations of phosphate in the absence of fluoride showed that phosphate had only slight effects on the succinic 2,6-dichlorophenolindophenol reductase component of the succinic oxidase system. In the absence of phosphate, various concentrations of fluoride showed an initial increase in activity followed by a decrease in activity of succinic 2,6-dichlorophenolindophenol reductase. In the presence of phosphate, fluoride caused marked inhibition of succinic 2,6-dichlorophenolindophenol reductase. It is believed that this inhibition results from an enzyme-fluorophosphate complex which has a lower dissociation constant than that of the enzyme-substrate complex. An oxidative phosphorylation study indicated that both respiration and phosphorylation were inhibited.

scholarly journals HISTOCHEMICAL STUDIES OF MITOCHONDRIAL VARIATION DURING AEROBIC GROWTH OF RESPIRATION-NORMAL BAKER'S YEAST

1965 ◽  
Vol 13 (5) ◽  
pp. 344-349 ◽  
Author(s):  
C. J. AVERS ◽  
F. H. LIN ◽  
C. R. PFEFFER
Keyword(s):  
Cytochrome Oxidase ◽  
Succinic Dehydrogenase ◽  
Growth Cycle ◽  
Autonomous Control ◽  
Mitochondrial Enzyme ◽  
Aerobic Growth ◽  
Acceleration Phase ◽  
Enzyme Systems ◽  
Zero Values ◽  
The Common

Histochemical localizations of cytochrome oxidase, succinic dehydrogenase, DPNH-tetrazolium reductase, and TPNH-tetrazolium reductase activities revealed at least two kinds of mitochondria in the intracellular population. The total chondriome in stationary phase cells contains about 45 mitochondria, all with cytochrome oxidase activity. But, only about 30 mitochondria per cell were active for dehydrogenase or reductases. The differences in mitochondrial enzyme activities persisted throughout the growth cycle, showing different numbers of active mitochondria and different rates of their increase and decrease for all four enzyme systems. Manometric data verified the differences between cytochrome oxidase and succinic dehydrogenase for the earlier phases of the growth cycle. In histochemical counts, zero values for all four enzymes occurred in late acceleration phase, but persisted into log phase only for the tetrazolium reductases. Both cytochrome oxidase- and succinic dehydrogenase-active mitochondria began to increase in numbers at the inception of log phase, but at very different rates. The demonstration of more than one kind of mitochondrion in the common nucleocytoplasmic system of a single cell was considered to be evidence of some measure of autonomous control of the mitochondrial phenotype.

scholarly journals Acellular probiotics and asparagic acid in the prevention of postpartum endometritis in cows

2020 ◽  
pp. 14-20
Author(s):  
P. Krasochko ◽  
T. Snitko
Keyword(s):  
Lactic Acid ◽  
Aspartic Acid ◽  
Uterine Cavity ◽  
Animal Husbandry ◽  
Low Ph ◽  
Stress Factors ◽  
Acid Complex ◽  
Local Immunity ◽  
Fermentation Products ◽  
Ph Level

Postpartum endometritis is one of the most widespread pathologies in animal husbandry. They often occur on the background of exposure on animals stress factors, microclimate disorders, complete feeding, which is accompanied by decrease of the resistance, leads to increasing morbidity, etc. The aim of the research is to develop a method of prevention of postpartum endometritis in cows using cell-free probiotics "Bacinil" and "Lactimet" with 4 % suspension of aspartic acid. Complex use of integrated cell-free probiotics "Bacinyl" and "Lactimet" with 4% suspension of asparagic acid for the prevention of postpartum endometritis in doses of 7.5 and 10 ml each at 3-fold use once a day for 3 days in a row allowed to obtain 100% preventive efficacy. The mechanism of action of probiotic "Bacinil" is based on the high activity of components of its composition - immunostimulants (lipopolysaccharides), bacteriocins and enzymes, probiotic "Lactimet" due to biosynthetic lactic acid and a complex of fermentation products. Complex application of probiotics and aspartic acid increases their bacteriostatic activity, which allows more actively suppress the proliferation of pathogenic and opportunistic microflora, complicating the flowing of postpartum endometritis; promotes liquefaction of exudate accumulated in the uterine cavity due to enzymes included in probiotic "Bacinil"; leads to activation of local immunity of endometrial tissues due to immunostimulating activity of components of "Bacinil" and "Lactimet" probiotics; creation of low pH level in the uterine cavity due to aspartic acid and biosynthetic lactic acid. Key words: cows, postpartum endometritis, prophylaxis, acellular probiotics, aspartic acid.

scholarly journals Carbon Dioxide Effects on Metabolism of Two Apple Fruit Cultivars

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 828A-828
Author(s):  
Chris B. Watkins ◽  
Juan-Pablo Fernández-Trujillo ◽  
Jacqueline F. Nock
Keyword(s):  
Carbon Dioxide ◽  
Organic Acid ◽  
Apple Fruit ◽  
Product Analysis ◽  
Fermentation Products ◽  
Fermentation Product ◽  
Postharvest Treatment

Susceptibility of apple fruit to CO2 can be affected by cultivar and postharvest treatment with diphenylamine (DPA). To study possible metabolic reasons for CO2 injury development, `Cortland' and `Law Rome' apple fruit were either untreated or treated with DPA at harvest, and then exposed to air or 45 kPa CO2 for up to 12 days. Fruit were sampled at 3-day intervals during treatment, and peel and flesh samples were taken for organic acid and fermentation product analysis. Additional fruit were removed to air and stored for 25 weeks for evaluation of injury. `Cortland' apple fruit had more external CO2 injury, but less internal CO2 injury than `Law Rome'. DPA treatment markedly reduced incidence of both external and internal injury. Fermentation products increased in peel and flesh of both cultivars with increasing exposure to CO2. However, acetaldehyde concentrations were ≈10 times higher in peel and flesh of `Law Rome' than `Cortland' apples. Ethanol concentrations in the flesh were similar in both cultivars, but were about twice as high in `Cortland' than `Law Rome' peel. Neither acetaldehyde nor ethanol concentrations were affected consistently by DPA treatment. Cultivar or DPA treatment did not affect accumulation of succinate, often regarded as the compound responsible for CO2 injury. These results do not indicate that acetaldehyde, ethanol, or succinate accumulation is responsible for CO2 injury in apple fruit.

scholarly journals Studies on the Metabolism of Locust Fat Body

1959 ◽  
Vol 36 (4) ◽  
pp. 665-675
Author(s):  
A. N. CLEMENTS
Keyword(s):  
Amino Acids ◽  
Sodium Acetate ◽  
Flight Muscle ◽  
Fat Body ◽  
Enzyme System ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Acid Cycle

1. The incorporation of glycine-14C (G), leucine-14C (G), sodium acetate-2-14C and glucose-14C (G) into Schistocerca fat body was studied under in vitro conditions, and the distribution of radioactivity in the various fat body fractions and the labelling of compounds within the fractions is described. 2. The overall picture was of high incorporation into fat and protein and of very low incorporation into glycogen. 3. Incubation with glycine-14C led to radioactivity appearing in the glycine and serine of the protein and of the amino acid pool. Incubation with sodium acetate-2-14C led to radioactivity appearing in glutamate, proline, aspartate and alanine, showing that the intermediates of the tricarboxylic acid cycle provide the carbon skeletons of certain amino acids. Glucose-14C was largely converted to trehalose. 4. Succinic dehydrogenase and the condensing enzyme system were shown to be present in fat body, contrary to previous reports. The succinic oxidase system was highly labile on homogenizing the tissue. 5. Fat body, unlike flight muscle, used glycine-14C and leucine-14C as respiratory substrates, and it is suggested that fat body acts like the vertebrate liver by transdeaminating amino acids and making them available for further metabolism by other tissues.

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