scholarly journals The distribution of six enzymes of oxidative metabolism along the rat nephron.

1984 ◽  
Vol 32 (7) ◽  
pp. 731-736 ◽  
Author(s):  
H B Burch ◽  
T E Bross ◽  
C A Brooks ◽  
B R Cole ◽  
O H Lowry
Keyword(s):  
Malic Enzyme ◽  
Quantitative Methods ◽  
Citrate Synthase ◽  
Rat Kidney ◽  
Acid Oxidation ◽  
Keto Acid ◽  
Coa Transferase ◽  
Freeze Dried ◽  
Wide Range ◽  
Thin Limb

Using quantitative methods, citrate synthase (CS), fumarase, beta-hydroxyacyl-coenzyme A (CoA) dehydrogenase (beta OAC), 3-keto-acid CoA transferase (KCT), malic dehydrogenase (MDH), and malic enzyme were measured in seven defined parts of the nephron and in thin limb and papilla areas dissected from freeze-dried microtome sections of rat kidney. The results not only show a wide range of activity along the nephron for each of the enzymes, but that the proportions between the enzymes vary markedly among the different parts of the nephron. This suggests the existence of major regional differences in the capacity to oxidize specific metabolites. The ratio between two citrate cycle enzymes, fumarase and CS, was 4- or 5-fold higher in proximal segments than in the glomerulus or thin limb areas. The ratio between beta OAC (an enzyme of fatty acid oxidation) and CS was 3- to 5-fold higher in the middle proximal segments than in glomeruli or thin limb and papilla areas. The key enzyme for ketone body metabolism, KCT, was essentially confined to the thick tubule segments. Malic enzyme, in contrast to the other five enzymes, was highest in the proximal straight segments. New methods, sufficiently sensitive for this histochemical study, are described for malic enzyme and 3-keto-acid CoA transferase.

scholarly journals Comparative studies on 3-oxo acid coenzyme A transferase from various rat tissues

1974 ◽  
Vol 142 (3) ◽  
pp. 619-627 ◽  
Author(s):  
Allan Fenselau ◽  
Kathleen Wallis
Keyword(s):  
Citrate Synthase ◽  
Ketone Bodies ◽  
Rat Kidney ◽  
Gel Filtration ◽  
Close Correlation ◽  
Rat Tissues ◽  
Transferase Activity ◽  
Marker Enzyme ◽  
Coa Transferase ◽  
Mitochondrial Fractions

1. Tissue activities, intracellular distribution as well as selected kinetic and molecular properties of succinyl-CoA–3-oxo acid CoA transferase (EC 2.8.3.5), which is an initiator of ketone body usage, were examined in rat kidney, heart, brain, skeletal muscle and liver. 2. The activities of the transferase in these tissues are similar to reported values and are somewhat affected by the homogenization medium. Higher recoveries of activity are obtained when a phosphate buffer is used during the homogenization; Tris solutions containing sucrose and mannitol lead to only slightly lower recoveries, but can be used in studies to determine the subcellular localization of the transferase activity. 3. A close correlation was observed between the relative activities of citrate synthase (a mitochondrial marker enzyme) and CoA transferase in the cytoplasmic, particulate and mitochondrial fractions from the five tissues. 4. The Km values for acetoacetate (measured in two different ways), the ratio of Vmax. values for the two enzyme-catalysed half-reactions, and succinate product inhibition are quite similar for the enzyme from each tissue. 5. The enzymes are also similar in molecular weight (with an approx. mol.wt. of 100000 as determined by gel filtration). All show an active band in isoelectric-focusing studies with pI 7.6, except for the enzyme from heart (pI 6.8). 6. The results demonstrate a mitochondrial origin for CoA transferase in these rat tissues and support the proposition that CoA transferase is a ketolytic enzyme, i.e. an enzyme uniquely involved in the complete oxidation of ketone bodies. The structural and functional similarities of these transferases suggest that factors other than differences in Km values account for differences in the utilization of ketone bodies by various tissues.

Computers in Geology - 25 Years of Progress

1994 ◽  
Keyword(s):  
Computer Modeling ◽  
Quantitative Methods ◽  
State Of The Art ◽  
International Association ◽  
Mathematical Geology ◽  
25Th Anniversary ◽  
The Earth ◽  
Wide Range ◽  
History Of ◽  
Mapping Techniques

This volume vividly demonstrates the importance and increasing breadth of quantitative methods in the earth sciences. With contributions from an international cast of leading practitioners, chapters cover a wide range of state-of-the-art methods and applications, including computer modeling and mapping techniques. Many chapters also contain reviews and extensive bibliographies which serve to make this an invaluable introduction to the entire field. In addition to its detailed presentations, the book includes chapters on the history of geomathematics and on R.G.V. Eigen, the "father" of mathematical geology. Written to commemorate the 25th anniversary of the International Association for Mathematical Geology, the book will be sought after by both practitioners and researchers in all branches of geology.

scholarly journals The CoGenT3 Study: Cognition and Gender Trends in Three American Generations

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 817-817
Author(s):  
Shana Stites
Keyword(s):  
Cognitive Impairment ◽  
Quantitative Methods ◽  
Cognitive Testing ◽  
Library Science ◽  
Sexual And Gender Minorities ◽  
Functional Impairments ◽  
Gender Minorities ◽  
Wide Range ◽  
And Gender ◽  
New Research

Abstract Many studies find gender differences in how older adults’ report on their memory, perform on cognitive testing, and manage functional impairments that can accompany cognitive impairment. Thus, understanding gender’s effects in aging and Alzheimer’s research is key for advancing methods to prevent, slow, manage, and diagnosis cognitive impairment. Our study, CoGenT3 – The study of Cognition and Gender in Three Generations – seeks to disambiguate the effects of gender on cognition in order to inform a conceptual model, guide innovations in measurement, and support future study. To accomplish this ambitious goal, we have gathered an interdisciplinary team with expertise in psychology, cognition, sexual and gender minorities, library science, measurement, quantitative methods, qualitative methods, and gender and women’s studies. The team benefits from the intersections of expertise in being able to build new research ideas, gain novel insights, and evaluate a wide-range of actions and re-actions but this novelty can also raise challenges.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

scholarly journals Postharvest Drying Techniques Regulate Secondary Metabolites and Anti-Neuroinflammatory Activities of Ganoderma lucidum

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4484
Author(s):  
Nooruddin-bin Sadiq ◽  
Da-Hye Ryu ◽  
Jwa-Yeong Cho ◽  
A-Hyeon Lee ◽  
Dae-Geun Song ◽  
...  
Keyword(s):  
Map Kinase ◽  
Ganoderma Lucidum ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Fructose Bisphosphate ◽  
Primary Metabolite ◽  
Ganoderic Acids ◽  
Bv2 Cells ◽  
Freeze Dried ◽  
Bv2 Microglia

Ganoderma lucidum extract is a potent traditional remedy for curing various ailments. Drying is the most important postharvest step during the processing of Ganoderma lucidum. The drying process mainly involves heat (36 h at 60 °C) and freeze-drying (36 h at −80 °C). We investigated the effects of different postharvest drying protocols on the metabolites profiling of Ganoderma lucidum using GC-MS, followed by an investigation of the anti-neuroinflammatory potential in LPS-treated BV2 microglial cells. A total of 109 primary metabolites were detected from heat and freeze-dried samples. Primary metabolite profiling showed higher levels of amino acids (17.4%) and monosaccharides (8.8%) in the heat-dried extracts, whereas high levels of organic acids (64.1%) were present in the freeze-dried samples. The enzymatic activity, such as ATP-citrate synthase, pyruvate kinase, glyceraldehyde-3-phosphatase dehydrogenase, glutamine synthase, fructose-bisphosphate aldolase, and D-3-phosphoglycerate dehydrogenase, related to the reverse tricarboxylic acid cycle were significantly high in the heat-dried samples. We also observed a decreased phosphorylation level of the MAP kinase (Erk1/2, p38, and JNK) and NF-κB subunit p65 in the heat-dried samples of the BV2 microglia cells. The current study suggests that heat drying improves the production of ganoderic acids by the upregulation of TCA-related pathways, which, in turn, gives a significant reduction in the inflammatory response of LPS-induced BV2 cells. This may be attributed to the inhibition of NF-κB and MAP kinase signaling pathways in cells treated with heat-dried extracts.

scholarly journals A high-throughput and sensitive methodology for the quantification of urinary 8-hydroxy-2′-deoxyguanosine: measurement with gas chromatography-mass spectrometry after single solid-phase extraction

2004 ◽  
Vol 380 (2) ◽  
pp. 541-548 ◽  
Author(s):  
Hai-Shu LIN ◽  
Andrew M. JENNER ◽  
Choon Nam ONG ◽  
Shan Hong HUANG ◽  
Matthew WHITEMAN ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Healthy Subjects ◽  
Solid Phase ◽  
Large Population ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Extraction ◽  
Freeze Dried ◽  
Wide Range

8-Hydroxy-2´-deoxyguanosine (8OHdG) is a widely used biomarker for the measurement of endogenous oxidative DNA damage. A sensitive method for the quantification of 8OHdG in urine by single solid-phase extraction and GC-MS (gas chromatography with MS detection) using selective ion monitoring is described in the present study. After solid-phase extraction, samples are freeze-dried, derivatized by trimethylsilylation and analysed by GC-MS. The urinary 8OHdG was quantified using heavy isotope dilution with [18O]8OHdG. The recovery of 8OHdG after the solid-phase extraction ranged from 70 to 80% for a wide range of urinary 8OHdG levels. Using 1 ml of urine, the limit of quantification was >2.5 nM (2.5 pmol/ml) and the calibration curve was linear in the range 2.5–200 nM. This method was applied to measure 8OHdG in urine samples from 12 healthy subjects. The intra- and inter-day variations were <9%. Urinary 8OHdG levels in spot urine samples from four healthy subjects were also measured for 1 week and, again, the variation was small. The presence of H2O2 in urine did not cause artifactual formation of 8OHdG. Since this assay is simple, rapid, sensitive and reproducible, it seems suitable to be used as a routine methodology for the measurement of urinary excretion of 8OHdG in large population studies.

Fatty acid oxidation and triacylglycerol hydrolysis are enhanced after chronic leptin treatment in rats

2002 ◽  
Vol 282 (3) ◽  
pp. E593-E600 ◽  
Author(s):  
Gregory R. Steinberg ◽  
Arend Bonen ◽  
David J. Dyck
Keyword(s):  
Fatty Acid ◽  
Citrate Synthase ◽  
Uncoupling Protein ◽  
Oxidative Capacity ◽  
Hormone Sensitive Lipase ◽  
Acid Oxidation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Triacylglycerol Hydrolysis ◽  
Hormone Sensitive

Leptin acutely increases fatty acid (FA) oxidation and triacylglycerol (TG) hydrolysis and decreases TG esterification in oxidative rodent muscle. However, the effects of chronic leptin administration on FA metabolism in skeletal muscle have not been examined. We hypothesized that chronic leptin treatment would enhance TG hydrolysis as well as the capacity to oxidize FA in soleus (SOL) muscle. Female Sprague-Dawley rats were infused for 2 wk with leptin (LEPT; 0.5 mg · kg−1 · day−1) by use of subcutaneously implanted miniosmotic pumps. Control (AD-S) and pair-fed (PF-S) animals received saline-filled implants. Subsequently, FA metabolism was monitored for 45 min in isolated, resting, and contracting (20 tetani/min) SOL muscles by means of pulse-chase procedures. Food intake (−33 ± 2%, P < 0.01) and body mass (−12.5 ± 4%, P = 0.01) were reduced in both LEPT and PF-S animals. Leptin levels were elevated (+418 ± 7%, P < 0.001) in treated animals but reduced in PF-S animals (−73 ± 8%, P< 0.05) relative to controls. At rest, TG hydrolysis was increased in leptin-treated rats (1.8 ± 2.2, AD-S vs. 23.5 ± 8.1 nmol/g wet wt, LEPT; P < 0.001). In contracting SOL muscles, TG hydrolysis (1.5 ± 0.6, AD-S vs. 3.6 ± 1.0 μmol/g wet wt, LEPT; P = 0.02) and palmitate oxidation (18.3 ± 6.7, AD-S vs. 45.7 ± 9.9 nmol/g wet wt, LEPT; P < 0.05) were both significantly increased by leptin treatment. Chronic leptin treatment had no effect on TG esterification either at rest or during contraction. Markers of overall (citrate synthase) and FA (hydroxyacyl-CoA dehydrogenase) oxidative capacity were unchanged with leptin treatment. Protein expression of hormone-sensitive lipase (HSL) was also unaltered following leptin treatment. Thus leptin-induced increases in lipolysis are likely due to HSL activation (i.e., phosphorylation). Increased FA oxidation secondary to chronic leptin treatment is not due to an enhanced oxidative capacity and may be a result of enhanced flux into the mitochondrion (i.e., carnitine palmitoyltransferase I regulation) or electron transport uncoupling (i.e., uncoupling protein-3 expression).

Induction of a fast-oxidative phenotype by chronic muscle stimulation: histochemical and metabolic studies

1996 ◽  
Vol 270 (1) ◽  
pp. C313-C320 ◽  
Author(s):  
C. N. Mayne ◽  
H. Sutherland ◽  
J. C. Jarvis ◽  
S. J. Gilroy ◽  
A. J. Craven ◽  
...  
Keyword(s):  
Time Course ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Adult Rabbit ◽  
Myosin Isoforms ◽  
Two Phase ◽  
Coa Transferase ◽  
Oxidative Phenotype ◽  
Aggregate Amount

Chronic electrical stimulation of skeletal muscle at 10 Hz induces fast-to-slow fiber type transformation. Does a lower aggregate amount of activity lead to a less complete transformation, or does it produce the same transformation over a longer time course? We examined this question by subjecting adult rabbit tibialis anterior and extensor digitorum longus muscles to continuous stimulation at 2.5 Hz for 2-12 wk. Most of the fibers acquired the histochemical and immunocytochemical characteristics of type 2A, not type 1, fibers. There was a corresponding rise in oxidative activity, but this was accompanied by a marked decline in anaerobic glycolysis. The activities of hexokinase and 3-oxoacid CoA-transferase stopped increasing after 2 wk, glutamate oxaloacetate transaminase after 4 wk, and beta-hydroxyacyl-CoA dehydrogenase after 6 wk of stimulation. Succinate dehydrogenase, citrate synthase, lactate dehydrogenase, and creatine phosphokinase continued to change up to 12 wk of stimulation. Changes in enzyme activity were not as rapid or as marked as those observed for stimulation at 10 Hz, and none showed the typical two-phase response of oxidative enzyme activities to stimulation at 10 Hz. The latter may therefore be dependent on induction of type 1 myosin isoforms.

Differences in quantitative methods for measuring subjective cognitive decline – results from a prospective memory clinic study

2016 ◽  
Vol 28 (9) ◽  
pp. 1513-1520 ◽  
Author(s):  
Asmus Vogel ◽  
Lise Cronberg Salem ◽  
Birgitte Bo Andersen ◽  
Gunhild Waldemar
Keyword(s):  
Depressive Symptoms ◽  
Cognitive Decline ◽  
Quantitative Methods ◽  
Cognitive Status ◽  
Cognitive Test ◽  
Subjective Cognitive Decline ◽  
Linear Regression Models ◽  
Memory Clinic ◽  
Subjective Memory ◽  
Wide Range

ABSTRACTBackground:Cognitive complaints occur frequently in elderly people and may be a risk factor for dementia and cognitive decline. Results from studies on subjective cognitive decline are difficult to compare due to variability in assessment methods, and little is known about how different methods influence reports of cognitive decline.Methods:The Subjective Memory Complaints Scale (SMC) and The Memory Complaint Questionnaire (MAC-Q) were applied in 121 mixed memory clinic patients with mild cognitive symptoms (mean MMSE = 26.8, SD 2.7). The scales were applied independently and raters were blinded to results from the other scale. Scales were not used for diagnostic classification. Cognitive performances and depressive symptoms were also rated. We studied the association between the two measures and investigated the scales’ relation to depressive symptoms, age, and cognitive status.Results:SMC and MAC-Q were significantly associated (r = 0.44, N = 121, p = 0.015) and both scales had a wide range of scores. In this mixed cohort of patients, younger age was associated with higher SMC scores. There were no significant correlations between cognitive test performances and scales measuring subjective decline. Depression scores were significantly correlated to both scales measuring subjective decline. Linear regression models showed that age did not have a significant contribution to the variance in subjective memory beyond that of depressive symptoms.Conclusions:Measures for subjective cognitive decline are not interchangeable when used in memory clinics and the application of different scales in previous studies is an important factor as to why studies show variability in the association between subjective cognitive decline and background data and/or clinical results. Careful consideration should be taken as to which questions are relevant and have validity when operationalizing subjective cognitive decline.

scholarly journals Oxidative properties of carp red and white muscle

1989 ◽  
Vol 143 (1) ◽  
pp. 321-331 ◽  
Author(s):  
C. D. Moyes ◽  
L. T. Buck ◽  
P. W. Hochachka ◽  
R. K. Suarez
Keyword(s):  
Amino Acids ◽  
White Muscle ◽  
Citrate Synthase ◽  
Ketone Bodies ◽  
Redox Balance ◽  
Fatty Acyl ◽  
Oxidation Rates ◽  
Substrate Preferences ◽  
Glycerophosphate Dehydrogenase ◽  
Wide Range

Substrate preferences of isolated mitochondria and maximal enzyme activities were used to assess the oxidative capacities of red muscle (RM) and white muscle (WM) of carp (Cyprinus carpio). A 14-fold higher activity of citrate synthase (CS) in RM reflects the higher mitochondrial density in this tissue. RM mitochondria oxidize pyruvate and fatty acyl carnitines (8:O, 12:O, 16:O) at similarly high rates. WM mitochondria oxidize these fatty acyl carnitines at 35–70% the rate of pyruvate, depending on chain length. WM has only half the carnitine palmitoyl transferase/CS ratio of RM, but similar ratios of beta-hydroxyacyl CoA dehydrogenase/CS. Ketone bodies are poor substrates for mitochondria from both tissues. In both tissues mitochondrial alpha-glycerophosphate oxidation was minimal, and alpha-glycerophosphate dehydrogenase was present at low activities, suggesting the alpha-glycerophosphate shuttle is of minor significance in maintaining cytosolic redox balance in either tissue. The mitochondrial oxidation rates of other substrates relative to pyruvate are as follows: alpha-ketoglutarate 90% (RM and WM); glutamate 45% (WM) and 70% (RM); proline 20% (WM) and 45% (RM). Oxidation of neutral amino acids (serine, glycine, alanine, beta-alanine) was not consistently detectable. These data suggest that RM and WM differ in mitochondrial properties as well as mitochondrial abundance. Whereas RM mitochondria appear to be able to utilize a wide range of metabolic fuels (fatty acids, pyruvate, amino acids but not ketone bodies), WM mitochondria appear to be specialized to use pyruvate.

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