Glycolytic enzyme activity in hypotonically treated boar spermatozoa

1999 ◽  
Vol 11 (8) ◽  
pp. 409 ◽  
Author(s):  
A. R. Jones ◽  
F. Piccolo
Keyword(s):  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Phosphate Buffer ◽  
Cytoplasmic Membrane ◽  
Glycolytic Enzyme ◽  
The Other ◽  
Simple Preparation ◽  
Chemical Inhibitors ◽  
Boar Spermatozoa ◽  
Phosphate Buffered Saline

Treatment of washed boar sperm with hypotonic phosphate buffer disrupted the cytoplasmic membrane and released the soluble contents and phosphofructokinase, but the other glycolytic enzymes and lactate dehydrogenase were retained. Addition of the appropriate substrates and co-factor(s) to preparations of treated cells in phosphate-buffered saline showed that enzyme activity could be re-instated. This simple preparation should be of assistance in the investigation of specific sections of the glycolytic pathway without the use of chemical inhibitors.

scholarly journals Regional enzyme development in rat brain. Enzymes associated with glucose utilization

1984 ◽  
Vol 218 (1) ◽  
pp. 131-138 ◽  
Author(s):  
S F Leong ◽  
J B Clark
Keyword(s):  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Rat Brain ◽  
Brain Regions ◽  
Glycolytic Enzyme ◽  
Glycolytic Potential ◽  
Key Enzyme ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Potential Enzyme Activity ◽  
The Brain

The development of key enzyme activities concerned with glucose metabolism was studied in six regions of the rat brain in animals from just before birth (-2 days) through the neonatal and suckling period until adulthood (60 days old). The brain regions studied were the cerebellum, medulla oblongata and pons, hypothalamus, striatum, mid-brain and cortex. The enzymes whose developmental patterns were investigated were hexokinase (EC 2.7.1.1), aldolase (EC 4.1.2.13), lactate dehydrogenase (EC 1.1.1.27) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49). Hexokinase, aldolase and lactate dehydrogenase activities develop as a single cluster in all the regions studied, although the timing of this development varies from region to region. Glucose-6-phosphate dehydrogenase activity, however, declines relative to glycolytic enzyme activity as the brain matures. When the different brain regions are compared, it is clear that the medulla develops its glycolytic potential, as indicated by its potential enzyme activity, considerably earlier than the other regions (hypothalamus, striatum and mid-brain), with the cortex and cerebellar activities developing even later. This enzyme developmental sequence correlates well with the neurophylogenetic development of the brain and adds support to the hypothesis that the development of the potential for glycolysis in the brain is a necessary prerequisite for the development of neurological competence.

Metabolic activity of hypotonically treated mature boar spermatozoa

1997 ◽  
Vol 9 (6) ◽  
pp. 583 ◽  
Author(s):  
A. R. Jones
Keyword(s):  
Oxygen Uptake ◽  
Metabolic Activity ◽  
Phosphate Buffer ◽  
Cytoplasmic Membrane ◽  
Mitochondrial Activity ◽  
Glycolytic Activity ◽  
Boar Sperm ◽  
Uptake Studies ◽  
Boar Spermatozoa

Treatment of washed boar sperm with hypotonic phosphate buffer removed the acrosome, disrupted the cytoplasmic membrane and almost completely separated the heads from the mid piece-tail segment. As assessed by oxygen uptake studies and their ability to oxidize14C-labelled substrates to 14CO2, hypotonically-treated cells exhibit low glycolytic activity yet mitochondrial activity remains high. Both lactate and glycerol 3-phosphate underwent oxidation and these substrates continued to be metabolized by this preparation which had been stored for up to 10 days at 4°C. Such preparations may be of assistance in the investigation of the biochemistry of boar sperm mitochondria.

scholarly journals Comparison of glycolytic enzyme and isoenzyme activity in breast cancers and dysplasia

2012 ◽  
Vol 65 (5-6) ◽  
pp. 200-205 ◽  
Author(s):  
Katica Bajin-Katic
Keyword(s):  
Breast Cancer ◽  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Enzyme Concentration ◽  
Glycolytic Enzyme ◽  
Disc Electrophoresis ◽  
Breast Cancers ◽  
Lactate Dehydrogenase Activity ◽  
Total Enzyme Activity

The study was aimed at assessing the total enzyme activity and the profile of breast cancer and dysplasia on the human material. In addition, the validity of data was evaluated from the aspect of improving diagnostics. Lactate dehydrogenase activity, as well as the profile of its isoenzymes, pyruvate kinase and hexokinase, were measured. The study included 60 samples of breast cancer, out of which 20 were benign breast tumours and 40 were 1st and 2nd degree dysplasia of the breast. The samples were collected from the patients operated at the Institute for Oncology of Faculty of Medicine in Sremska Kamenica. Lactate dehydrogenase isoenzymes were separated by the vertical polyacrylamide gel disc electrophoresis according to the slightly modified Brewer and Ashworth?s method. The activity of all the tested enzymes was measured under the conditions of linear kinetics in the function of time and enzyme concentration. Lactate dehydrogenase-5 was found in 88% of the analyzed breast cancer samples, whereas it was not detected in breast dysplasia. Pyruvate kinase (4.-isoenzyme) was about 50 times higher and the activity of hexokinase was 3 times higher in breast cancer than in breast dysplasia. Lactate dehydrogenase-5 and pyruvate kinase (4.-isoenzyme) are particularly important and reliable markers of malignity. The results obtained for quantitative and qualitative changes in the enzyme activity can be used to improve diagnostics and early diagnostics of malignant breast neoplasm.

Metabolism of lactate by mature boar spermatozoa

1997 ◽  
Vol 9 (2) ◽  
pp. 227 ◽  
Author(s):  
A. R. Jones
Keyword(s):  
Lactate Dehydrogenase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Energy Charge ◽  
High Energy ◽  
The Other ◽  
Glycolytic Metabolism ◽  
Lactate Transport ◽  
Lactate Dehydrogenase Isozymes ◽  
Charge Potential ◽  
Boar Spermatozoa

Boar sperm oxidatively metabolized fructose, glucose, glycerol, glycerol 3-phosphate and lactate to CO2 but pyruvate produced only small amounts of CO2 and this was almost completely prevented when endogenous glycolytic metabolism was inhibited. Lactate was the preferred substrate over fructose, glycerol and glycerol 3-phosphate and when lactate was offered in the presence of pyruvate, lactate was preferentially oxidized to CO2. The rate of oxidation of fructose, glycerol and glycerol 3-phosphate was approximately halved in the presence of equi-molar concentrations of lactate and the metabolism of lactate was progressively decreased in the presence of increasing concentrations of mersalyl, an inhibitor of lactate transport. Sperm maintained a high energy charge potential when incubated with lactate as substrate in the presence or absence of bromopyruvate, an inhibitor of endogenous glycolytic metabolism. This evidence confirms that it is lactate, rather than pyruvate, that enters the mitochondria thereby constituting a lactate–pyruvate transport system in these cells for regenerating cytoplasmic nicotinamide adenine dinucleotide (NAD +). Electrophoretic examination of the lactate dehydrogenase isozymes from sperm and several other tissues of the boar showed that sperm contained almost entirely an isozyme which was not present in the other tissues.

New developments in analysis of isoenzymes separated by "high-performance" liquid chromatography.

1979 ◽  
Vol 25 (9) ◽  
pp. 1600-1607 ◽  
Author(s):  
T D Schlabach ◽  
J A Fulton ◽  
P B Mockridge ◽  
E C Toren
Keyword(s):  
High Performance Liquid Chromatography ◽  
Enzyme Activity ◽  
Liquid Chromatography ◽  
Lactate Dehydrogenase ◽  
High Performance ◽  
Dynamic Range ◽  
The Other ◽  
Linear Dynamic Range ◽  
Fluorescence Detector ◽  
Linear Dynamic

Abstract We have developed two enzyme analyzers for use in "high-performance" liquid chromatography. In both systems two detectors are used, placed after the column effluent has been combined with assay reagent. In one system, an absorbance detector is placed before and after a post-column reaction coil. Peaks observed at one detector are subtracted from those at the other, to produce a two-point measurement of enzyme activity. The linear dynamic range was 17--1700 U/L for lactate dehydrogenase (EC 1.1.1.27). In the other system, two reaction coils were used and a single fluorescence detector was placed at the end of each coil. These coils were kept at different temperatures, and an automated switching valve diverted equal amounts of column effluent and reagent into both coils. The fluorescence readings were then subtracted to produce a differential measurement of enzyme activity. The linear dynamic range was 20--1000 U/L. We used both systems to chromatographically analyze lactate dehydrogenase isoenzymes, and could separately determine both the distribution and activity of sample isoenzymes.

Ultrastructure of developing visual cortical synapses in the cat superior colliculus

1991 ◽  
Vol 49 ◽  
pp. 156-157
Author(s):  
Caroline A. Miller ◽  
Laura L. Bruce
Keyword(s):  
Superior Colliculus ◽  
Phosphate Buffer ◽  
Receptive Fields ◽  
Visual Cortical Area ◽  
Cortical Synapses ◽  
Visual Cortical ◽  
And Function ◽  
Phosphate Buffered Saline ◽  
The Brain ◽  
Cat Superior Colliculus

The first visual cortical axons arrive in the cat superior colliculus by the time of birth. Adultlike receptive fields develop slowly over several weeks following birth. The developing cortical axons go through a sequence of changes before acquiring their adultlike morphology and function. To determine how these axons interact with neurons in the colliculus, cortico-collicular axons were labeled with biocytin (an anterograde neuronal tracer) and studied with electron microscopy.Deeply anesthetized animals received 200-500 nl injections of biocytin (Sigma; 5% in phosphate buffer) in the lateral suprasylvian visual cortical area. After a 24 hr survival time, the animals were deeply anesthetized and perfused with 0.9% phosphate buffered saline followed by fixation with a solution of 1.25% glutaraldehyde and 1.0% paraformaldehyde in 0.1M phosphate buffer. The brain was sectioned transversely on a vibratome at 50 μm. The tissue was processed immediately to visualize the biocytin.

Total lactate dehydrogenase and its isoenzymes in serum in the presence of penicillamine and other sulfhydryl compounds.

1977 ◽  
Vol 23 (2) ◽  
pp. 229-233 ◽  
Author(s):  
L L Gershbein ◽  
K G Raikoff
Keyword(s):  
Lactate Dehydrogenase ◽  
Disc Electrophoresis ◽  
The Other ◽  
Rat Serum ◽  
Initial Concentration ◽  
Ldh Isoenzymes ◽  
Allosteric Effectors ◽  
Sulfhydryl Compounds

Abstract Toward delineation of changes in total lactate dehydrogenase (LDH) and in the distribution of LDH isoenzymes as assessed by polyacrylamide disc electrophoresis, we inbucated human and rat sera with various agents, notably sulfhydryl compounds. Although artefacts were apparent when these agents were used without preliminary adjustment of pH, we saw little alteration in total unitage when one or two volumes of serum was mixed with one volume of any of several thiols, especially penicillamine, at an initial concentration of 0.4 mol/liter and pH 7.0-7.5. Under these conditions, penicillamine caused a loss in LDH-5 after incubation for 1 h at 25 degrees C together with small decreases in mobility of the other four isoenzymes toward the anode. A zymosan region appeared below the albumin and tracking dye area. With longer periods of incubation of rat serum with penicillamine or alpha-mercaptosuccinate, a novel band in the zymogram was noted just above the LDH-4 peak. The observations are discussed in terms of allosteric effectors.

scholarly journals Charged Residues Flanking the Transmembrane Domain of Two Related Toxin–Antitoxin System Toxins Affect Host Response

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 329
Author(s):  
Andrew Holmes ◽  
Jessie Sadlon ◽  
Keith Weaver
Keyword(s):  
Amino Acid ◽  
Enterococcus Faecalis ◽  
Host Response ◽  
Cytoplasmic Membrane ◽  
Transmembrane Domain ◽  
The Other ◽  
Type I ◽  
Transcriptomic Response ◽  
Specific Amino Acid ◽  
Transporter Protein

A majority of toxins produced by type I toxin–antitoxin (TA-1) systems are small membrane-localized proteins that were initially proposed to kill cells by forming non-specific pores in the cytoplasmic membrane. The examination of the effects of numerous TA-1 systems indicates that this is not the mechanism of action of many of these proteins. Enterococcus faecalis produces two toxins of the Fst/Ldr family, one encoded on pheromone-responsive conjugative plasmids (FstpAD1) and the other on the chromosome, FstEF0409. Previous results demonstrated that overexpression of the toxins produced a differential transcriptomic response in E. faecalis cells. In this report, we identify the specific amino acid differences between the two toxins responsible for the differential response of a gene highly induced by FstpAD1 but not FstEF0409. In addition, we demonstrate that a transporter protein that is genetically linked to the chromosomal version of the TA-1 system functions to limit the toxicity of the protein.

A Rapid Electrophoretic Method for the Determination of the Isoenzymes of Serum Lactate Dehydrogenase

1966 ◽  
Vol 12 (5) ◽  
pp. 308-313 ◽  
Author(s):  
Albert W Opher ◽  
Charles S Collier ◽  
Joseph M Miller
Keyword(s):  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Quantitative Determination ◽  
Serum Lactate ◽  
Serum Lactate Dehydrogenase ◽  
Electrophoretic Method ◽  
The Individual ◽  
Electrophoretic Procedure ◽  
Purple Formazan

Abstract A convenient electrophoretic procedure for the separation and quantitation of lactate dehydrogenase (LDH) isoenzymes is described. The system uses polyacetate Sepraphore III strips.* The areas of activity are shown by incubation with an LDH substrate combined with tetra-nitro-blue-tetrazolium. The reduction of the latter to the purple formazan is quantitatively related to the enzyme activity. Quantitative determination of the individual colored areas is performed by densitometry.

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