scholarly journals Effects of inositol starvation on the levels of inositol phosphates and inositol lipids in Neurospora crassa

1993 ◽  
Vol 292 (3) ◽  
pp. 805-811 ◽  
Author(s):  
P L Lakin-Thomas
Keyword(s):  
Neurospora Crassa ◽  
Phytic Acid ◽  
Inositol Phosphates ◽  
Acid Synthesis ◽  
Extracellular Medium ◽  
Absolute Requirement ◽  
Solid Agar ◽  
Inositol Lipids ◽  
Agar Media ◽  
High Concentrations

An inositol-requiring strain of Neurospora crassa was labelled during growth in liquid medium with [3H]inositol, and the levels of inositol phosphates and phosphoinositides were determined under inositol-sufficient and inositol-starved conditions. Because the mutant has an absolute requirement for inositol, the total mass of inositol-containing compounds could be determined. Inositol-containing lipids were identified by deacylation and co-migration with standards on h.p.l.c.; PtdIns3P, PtdIns4P, and PtdIns(4,5)P2 were found in approximately equal amounts, in addition to large amounts of PtdIns. Inositol starvation decreased the level of PtdIns to 10% of the sufficient level, and decreased the levels of the other phosphoinositides to about 25%. A number of inositol phosphates were found, including several InsP3s, InsP4s and InsP5s and phytic acid. Ins(1,4,5)P3 was identified by co-migration with standards on h.p.l.c. and by digestion with inositol phosphomonoesterase. High concentrations of all inositol phosphates were found in the extracellular medium in inositol-starved cultures. Inositol starvation on both liquid and solid agar media decreased the intracellular levels of some inositol phosphates, but increased the levels of phytic acid and several other inositol phosphates which may be its precursors and/or breakdown products. These results may indicate that inositol starvation induces phytic acid synthesis as a protection against the free-radical production and lipid peroxidation characteristic of inositol-less death.

TEM processing procedure for a bacillus organism grown on solid media

1990 ◽  
Vol 48 (3) ◽  
pp. 624-625
Author(s):  
Jane Payne ◽  
Philip Coudron
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Fume Hood ◽  
Vacuum Aspiration ◽  
Solid Media ◽  
Transmission Electron ◽  
Solid Agar ◽  
Processing Procedure ◽  
Agar Media ◽  
Rat Bone

This transmission electron microscopy (TEM) procedure was designed to examine a gram positive spore-forming bacillus in colony on various solid agar media with minimal artifact. Cellular morphology and organization of colonies embedded in Poly/Bed 812 resin (P/B) were studied. It is a modification of procedures used for undecalcified rat bone and Stomatococcus mucilaginosus.Cultures were fixed and processed at room temperature (RT) under a fume hood. Solutions were added with a Pasteur pipet and removed by gentle vacuum aspiration. Other equipment used is shown in Figure 3. Cultures were fixed for 17-18 h in 10-20 ml of RT 2% phosphate buffered glutaraldehyde (422 mosm/KgH2O) within 5 m after removal from the incubator. After 3 (30 m) changes in 0.15 M phosphate buffer (PB = 209-213 mosm/KgH2O, pH 7.39-7.41), colony cut-outs (CCO) were made with a scalpel.

Natural Products and Extracts as Xantine Oxidase Inhibitors – A Hope for Gout Disease?

2020 ◽  
Vol 26 ◽  
Author(s):  
Ilkay Erdogan Orhan ◽  
Fatma Sezer Senol Deniz
Keyword(s):  
Natural Products ◽  
Uric Acid ◽  
Waste Product ◽  
Acid Synthesis ◽  
Intermediate Compound ◽  
Living System ◽  
Ginsenoside Rd ◽  
Drug Classes ◽  
Urate Crystal ◽  
High Concentrations

: Xanthine oxidase (EC 1.17.3.2) (XO) is one of the main enzymatic sources that create reactive oxygen species (ROS) in the living system. It is a dehydrogenase enzyme that performs electron transfer to nicotinamide adenine dinucleotide (NAD+ ), while oxidizing hypoxanthin, which is an intermediate compound in purine catabolism, first to xanthine and then to uric acid. XO turns into an oxidant enzyme that oxidizes thiol groups under certain stress conditions in the tissue. The last metabolic step, in which hypoxanthin turns into uric acid, is catalyzed by XO. Uric acid, considered a waste product, can cause kidney stones and gouty-type arthritis as it is crystallized, when present in high concentrations. Thus, XO inhibitors are one of the drug classes used against gout, a purine metabolism disease that causes urate crystal storage in the joint and its surroundings caused by hyperuricemia. Urate-lowering therapy include XO inhibitors that reduce uric acid production as well as uricosuric drugs that increase urea excretion. Current drugs that obstruct uric acid synthesis through XO inhibition are allopurinol, febuxostat, and uricase. However, since the side effects, safety and tolerability problems of some current gout medications still exist; intensive research is ongoing to look for new, effective, and safer XO inhibitors of natural or synthetic origins for the treatment of the disease. In the present review, we aimed to assess in detail XO inhibitory capacities of pure natural compounds along with the extracts from plants and other natural sources via screening Pubmed, Web of Science (WoS), Scopus, and Google Academic. The data pointed out to the fact that natural products, particularly phenolics such as flavonoids (quercetin, apigenin, and scutellarein), tannins (agrimoniin and ellagitannin), chalcones (melanoxethin), triterpenes (ginsenoside Rd and ursolic acid), stilbenes (resveratrol and piceatannol), alkaloids (berberin and palmatin) have a great potential for new XO inhibitors capable of use against gout disease. In addition, not only plants but other biological sources such as microfungi, macrofungi, lichens, insects (silk worms, ants, etc) seem to be the promising sources of novel XO inhibitors.

scholarly journals The regulation of glyceride synthesis in isolated white-fat cells. The effects of palmitate and lipolytic agents

1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Fat Cells ◽  
Glyceride Synthesis ◽  
Glucose Incorporation ◽  
High Concentrations ◽  
Stimulation Of

1. 0.5mm-Palmitate stimulated incorporation of [U-14C]glucose into glyceride glycerol and fatty acids in normal fat cells in a manner dependent upon the glucose concentration. 2. In the presence of insulin the incorporation of 5mm-glucose into glyceride fatty acids was increased by concentrations of palmitate, adrenaline and 6-N-2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate up to 0.5mm, 0.5μm and 0.5mm respectively. Higher concentrations of these agents produced progressive decreases in the rate of glucose incorporation into fatty acids. 3. The effects of palmitate and lipolytic agents upon the measured parameters of glucose utilization were similar, suggesting that the effects of lipolytic agents are mediated through increased concentrations of free fatty acids. 4. In fat cells from 24h-starved rats, maximal stimulation of glucose incorporation into fatty acids was achieved with 0.25mm-palmitate. Higher concentrations of palmitate were inhibitory. In fat cells from 72h-starved rats, palmitate only stimulated glucose incorporation into fatty acids at high concentrations of palmitate (1mm and above). 5. The ability of fat cells to incorporate glucose into glyceride glycerol in the presence of palmitate decreased with increasing periods of starvation. 6. It is suggested that low concentrations of free fatty acids stimulate fatty acid synthesis from glucose by increasing the utilization of ATP and cytoplasmic NADH for esterification of these free fatty acids. When esterification of free fatty acids does not keep pace with their provision, inhibition of fatty acid synthesis occurs. Provision of free fatty acids far in excess of the esterification capacity of the cells leads to uncoupling of oxidative phosphorylation and a secondary stimulation of fatty acid synthesis from glucose.

scholarly journals Light and electron microscopical observations of the effects of high-density lipoprotein on growth of Plasmodium falciparum in vitro

Parasitology ◽  
2004 ◽  
Vol 128 (6) ◽  
pp. 577-584 ◽  
Author(s):  
H. IMRIE ◽  
D. J. P. FERGUSON ◽  
M. CARTER ◽  
J. DRAIN ◽  
A. SCHIFLETT ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
High Density Lipoprotein ◽  
Light And Electron Microscopy ◽  
Density Lipoprotein ◽  
Acid Synthesis ◽  
High Density ◽  
High Concentrations ◽  
Electron Microscopical ◽  
Necessary And Sufficient

Human serum high-density lipoprotein (HDL) is necessary and sufficient for the short-term maintenance of Plasmodium falciparum in in vitro culture. However, at high concentrations it is toxic to the parasite. A heat-labile component is apparently responsible for the stage-specific toxicity to parasites within infected erythrocytes 12–42 h after invasion, i.e. during trophozoite maturation. The effects of HDL on parasite metabolism (as determined by nucleic acid synthesis) are evident at about 30 h after invasion. Parasites treated with HDL show gross abnormalities by light and electron microscopy.

Aeromonas hydrophila in Shellfish Growing Waters: Incidence and Media Evaluation

1989 ◽  
Vol 52 (1) ◽  
pp. 7-12 ◽  
Author(s):  
CARLOS ABEYTA ◽  
STEPHEN D. WEAGANT ◽  
CHARLES A. KAYSNER ◽  
MARLEEN M. WEKELL ◽  
ROBERT F. STOTT ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Environmental Samples ◽  
Enterotoxin Production ◽  
Beef Extract ◽  
Solid Agar ◽  
Agar Media

Levels of Aeromonas hydrophila determined for the shellfish growing area of Grays Harbor, Washington, ranged from 3 to 4600/100 g in oysters and from 3 to 2400/100 ml in water. Of isolates tested, 80% produced a hemolysin, a trait reported to correlate with enterotoxin production and pathogenicity. Two enrichment broths, Tryptic Soy Broth with ampicillin (TSBA) and Modified Rimler Shotts Broth (MRSB) were compared in combination with three solid agar media: Rimler Shotts (RS), Peptone Beef Extract Glycogen (PBG), and MacConkey's (MCA) agars. TSBA was far superior to MRSB in isolating this species from the environmental samples tested.

Effect of extracellular calcium on superoxide release by rat alveolar macrophages

1983 ◽  
Vol 54 (5) ◽  
pp. 1249-1253 ◽  
Author(s):  
H. J. Forman ◽  
J. Nelson
Keyword(s):  
Concanavalin A ◽  
Alveolar Macrophages ◽  
Extracellular Calcium ◽  
Extracellular Medium ◽  
Absolute Requirement ◽  
Superoxide Release

Alveolar macrophages can be stimulated to release superoxide into the extracellular medium. The mechanism of activation of superoxide release has been reported to be mediated by the movement of Ca2+ into the cytosol, but the involvement of extracellular Ca2+ in this process has remained uncertain. Extracellular Ca2+ was not an absolute requirement for activation of superoxide release; however, 1.3 mM extracellular Ca2+ caused an approximate twofold enhancement of superoxide release stimulated by either concanavalin A or formyl-methionyl-leucyl-phenylalanine but had no effect on digitonin-stimulated superoxide release. Concanavalin A-stimulated superoxide was inhibited by the “Ca2+ entry blockers,” Mn2+ (1 microM) or methoxyverapamil (D-600) (100 microM). Inhibition by Mn2+ was competitive with extracellular Ca2+, whereas inhibition by D-600 was noncompetitive. Neither inhibitor, however, affected superoxide release after initiation. Thus activation of superoxide release by alveolar macrophages can be accomplished, in part, through the entrance of Ca2+ into the cell.

Genetics of Phytic Acid Synthesis and Accumulation

Food Phytates ◽  
2001 ◽  
Author(s):  
Victor Raboy ◽  
Kevin Young ◽  
Steven Larson ◽  
Allen Cook
Keyword(s):  
Phytic Acid ◽  
Acid Synthesis

The use of cells doubly labelled with [14C]inositol and [3H]inositol to search for a hormone-sensitive inositol lipid pool with atypically rapid metabolic turnover

1989 ◽  
Vol 122 (1) ◽  
pp. 379-389 ◽  
Author(s):  
S. H. Maccallum ◽  
C. J. Barker ◽  
P. A. Hunt ◽  
N. S. Wong ◽  
C. J. Kirk ◽  
...  
Keyword(s):  
Cell Lines ◽  
Inositol Phosphates ◽  
Phosphatidyl Inositol ◽  
Receptor Activation ◽  
Inositol Monophosphatase ◽  
Lipid Pool ◽  
Inositol Lipids ◽  
Prostaglandin F ◽  
Hormone Sensitive ◽  
Stimulation Of

ABSTRACT Some, though not all, previous studies have suggested that the inositol lipid which is hydrolysed during transmembrane signalling in response to receptor activation might be drawn from a metabolically discrete and relatively small hormone-sensitive lipid pool that turns over more rapidly than the bulk of membrane inositol lipid. In order to seek evidence for the existence of this putative hormone-sensitive lipid pool, we have double-labelled cells by growing them for 3 days in a medium containing [14C]inositol and then supplying them with [3H]inositol for the final 2 h before stimulation. We anticipated that stimulation of these doubly labelled cells might provoke the formation, from the postulated hormone-sensitive pool, of small quantities of relatively 3H-enriched inositol phosphates, and that these could be harvested from cells (provided that the cytosolic inositol monophosphatase and inositol 1,4-bisphosphate/inositol 1,3,4-trisphosphate 1-phosphatase activities are first inhibited by Li+). Experiments of this type, using both vasopressin-stimulated WRK1 rat mammary tumour cells and 3T3 mouse fibroblasts stimulated by prostaglandin F2α, have largely failed to demonstrate the formation of relatively 3H-enriched inositol phosphates. There was a tendency for phosphatidyl-inositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate to have slightly higher 3H: 14C ratios than phosphatidylinositol, but the 3H: 14C ratios of the inositol phosphates formed in stimulated cells were not substantially greater than the 3H: 14C ratios of the inositol lipids. We therefore conclude, at least for the two cell lines that we studied, that hormone-stimulated inositol lipid hydrolysis can call, either directly or indirectly, upon the majority of the inositol lipid complement of the stimulated cell. Journal of Endocrinology (1989) 122, 379–389

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