scholarly journals A rapid separation method for inositol phosphates and their isomers

1987 ◽  
Vol 245 (3) ◽  
pp. 655-660 ◽  
Author(s):  
K A Wreggett ◽  
R F Irvine
Keyword(s):  
Anion Exchange ◽  
Inositol Phosphates ◽  
Inositol Trisphosphate ◽  
Separation Method ◽  
Ammonium Formate ◽  
Rapid Separation ◽  
Large Numbers

A technique is described using ACCELL QMA anion-exchange SEP-PAKs (Waters Associates) with ammonium formate-based solutions, whereby a sample can be processed within minutes to yield resolution of inositol phosphates. Isomers of inositol trisphosphate can then be separated by using this technique in combination with a rapid (5-6 min) isocratic h.p.l.c. procedure. The use of QMA SEP-PAKs offers a degree of reproducibility comparable with that of h.p.l.c. while maintaining the capacity for automation, allowing large numbers of samples to be processed rapidly.

scholarly journals Glucose-induced accumulation of inositol trisphosphates in isolated pancreatic islets. Predominance of the 1,3,4-isomer

1986 ◽  
Vol 237 (1) ◽  
pp. 259-263 ◽  
Author(s):  
J Turk ◽  
B A Wolf ◽  
M L McDaniel
Keyword(s):  
Pancreatic Islets ◽  
Anion Exchange ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Inositol Trisphosphate ◽  
Isolated Pancreatic Islets ◽  
Stimulus Secretion Coupling

Anion-exchange h.p.l.c. analysis of [3H]inositol phosphates derived from glucose-stimulated isolated pancreatic islets that had been prelabelled with myo-[3H]inositol revealed that the predominant inositol trisphosphate was the 1,3,4-isomer [Ins(1,3,4)P3]. The 1,4,5-isomer [Ins(1,4,5)P3] was also detectable, as was a more polar inositol phosphate with the chromatographic properties of inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4]. Glucose-induced accumulation of Ins(1,3,4)P3 was augmented by Li+ and occurred after maximal accumulation of Ins(1,4,5)P3. These findings suggest a possible role for Ins(1,3,4)P3 or its probable precursor Ins(1,3,4,5)P4 in stimulus-secretion coupling in pancreatic islets.

scholarly journals A Miniaturized Column Chromatography Method for Measuring Receptor-Mediated Inositol Phosphate Accumulation

2004 ◽  
Vol 9 (4) ◽  
pp. 343-353 ◽  
Author(s):  
Elfrida R. Benjamin ◽  
Sarah L. Haftl ◽  
Dimitris N. Xanthos ◽  
Gregg Crumley ◽  
Mohamed Hachicha ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Column Chromatography ◽  
Large Volume ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Assay Method ◽  
Signal To Noise ◽  
Chromatography Method ◽  
Phosphate Accumulation ◽  
Inositol Phosphate Accumulation

Inositol phosphates (IPs), such as 1,4,5-inositol-trisphosphate (IP3), comprise a ubiquitous intracellular signaling cascade initiated in response to G protein-coupled receptor-mediated activation of phospholipase C. Classical methods for measuring intracellular accumulation of these molecules include time-consuming high-performance liquid chromatography (HPLC) separation or large-volume, gravity-fed anion-exchange column chromatography. More recent approaches, such as radio-receptor and AlphaScreen™ assays, offer higher throughput. However, these techniques rely on measurement of IP3 itself, rather than its accumulation with other downstream IPs, and often suffer from poor signal-to-noise ratios due to the transient nature of IP3. The authors have developed a miniaturized, anion-exchange chromatography method for measuring inositol phosphate accumulation in cells that takes advantage of signal amplification achieved through measuring IP3 and downstream IPs. This assay uses centrifugation of 96-well-formatted anion-exchange mini-columns for the isolation of radiolabeled inositol phosphates from cell extracts, followed by low-background dry-scintillation counting. This improved assay method measures receptor-mediated IP accumulation with signal-to-noise and pharmacological values comparable to the classical large-volume, column-based methods. Assay validation data for recombinant muscarinic receptor 1, galanin receptor 2, and rat astrocyte metabotropic glutamate receptor 5 are presented. This miniaturized protocol reduces reagent usage and assay time as compared to large-column methods and is compatible with standard 96-well scintillation counters.

scholarly journals Human lipoproteins comprise at least 12 different classes that are 1 lognormally distributed.

2021 ◽  
Author(s):  
Tomokazu Konishi ◽  
Risako Fujiwara ◽  
Tadaaki Saito ◽  
Tadaaki Saito ◽  
Nozomi Satou ◽  
...  
Keyword(s):  
Human Serum ◽  
Separation Method ◽  
High Gravity ◽  
Serum Samples ◽  
Rapid Separation ◽  
Human Serum Samples ◽  
Multiple Factors ◽  
Mixed Classes ◽  
Time Required ◽  
Enzymatic Methods

Lipoproteins in medical samples have been measured by enzymatic methods that coincide with conventional ultracentrifugation. However, the high gravity and time required for ultracentrifugation can cause sample degradation. This study presents the results of HPLC, a gentler and rapid separation method, for 55 human serum samples. The elution patterns were analysed parametrically, and the attribute of each class was confirmed biochemically. Human samples contained 12 classes of lipoproteins, each of which may consist primarily of proteins. There are three classes of VLDLs. The level of each class was distributed lognormally, and the standard amount and the 95% range were estimated. Enzymatic methods measure the levels of several mixed classes. This lognormal character suggests that the levels are controlled by the synergy of multiple factors.

scholarly journals Properties of receptor-controlled inositol trisphosphate formation in parotid acinar cells

1985 ◽  
Vol 225 (1) ◽  
pp. 263-266 ◽  
Author(s):  
D L Aub ◽  
J W Putney
Keyword(s):  
Inositol Phosphates ◽  
Inositol Trisphosphate ◽  
Calcium Ionophore ◽  
Acinar Cells ◽  
Receptor Occupancy ◽  
Parotid Acinar Cells ◽  
Parotid Cells ◽  
Rat Parotid ◽  
K Release ◽  
Substance P Receptors

Activation of muscarinic receptors in rat parotid cells results in breakdown of polyphosphoinositides liberating inositol phosphates, including inositol trisphosphate. Formation of inositol trisphosphate appears independent of agonist-induced Ca2+ mobilization, since neither formation nor degradation of inositol trisphosphate are appreciably altered in low-calcium media, and elevation of cytosolic Ca2+ with a calcium ionophore does not cause an increase in cellular inositol trisphosphate. Further, activation of substance P receptors and alpha 1-adrenoreceptors, but not beta-adrenoreceptors, increases inositol trisphosphate formation. The dose-response curve for methacholine activation of inositol trisphosphate formation more closely approximates the curve for receptor occupancy than for Ca2+-activated K+ release. These results are all consistent with the suggestion that inositol trisphosphate could function as a second messenger linking receptor occupation to cellular Ca2+ mobilization.

Analyses of Inositol Phosphates and by Strong Anion Exchange (SAX)-HPLC

2021 ◽  
pp. 365-378
Author(s):  
Debabrata Laha ◽  
Marília Kamleitner ◽  
Philipp Johnen ◽  
Gabriel Schaaf
Keyword(s):  
Anion Exchange ◽  
Inositol Phosphates ◽  
Strong Anion Exchange

Applications of fast protein liquid chromatography TM in the separation of plasma proteins in urine and cerebrospinal fluid.

1983 ◽  
Vol 29 (9) ◽  
pp. 1635-1640 ◽  
Author(s):  
E H Cooper ◽  
R Turner ◽  
E A Johns ◽  
H Lindblom ◽  
V J Britton
Keyword(s):  
Cerebrospinal Fluid ◽  
Liquid Chromatography ◽  
Anion Exchange ◽  
Plasma Proteins ◽  
Fast Protein Liquid Chromatography ◽  
Rapid Separation ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Urine Specimens ◽  
Bence Jones Proteins

Abstract Fast Protein Liquid Chromatography TM (FPLC), in which an anion-exchange column is used, provides rapid separation and reproducible profiling of the plasma proteins in urine and cerebrospinal fluid (CSF). Chromatographic separation of the proteins takes 1 h for urine specimens and 45 min for CSF. The elution sequence from the anion-exchange column is similar to the electrophoretic mobility. Individual proteins have the same retention times independently of which type of specimen is used. The elution characteristics of 21 plasma proteins have been identified. We illustrated some applications of this system, including the profiling of tubular protein-uria, the isolation of Bence Jones proteins from urine, and the investigation of hemoglobin-derived products in the CSF.

Activation of PtdIns(4,5)P2-sensitive phospholipase C in rabbit tracheal epithelial cells

1994 ◽  
Vol 266 (2) ◽  
pp. C397-C405 ◽  
Author(s):  
C. M. Liedtke
Keyword(s):  
Epithelial Cells ◽  
Phospholipase C ◽  
Pertussis Toxin ◽  
Inositol Phosphates ◽  
Inositol Trisphosphate ◽  
Isolated Cells ◽  
Tracheal Epithelial Cells ◽  
Adrenergic Antagonist ◽  
Tracheal Epithelial

A role for phospholipase C hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] as a mechanism of alpha 2-adrenergic signal transduction in rabbit tracheal epithelial cells (tracheocytes) was investigated in isolated cells grown in in vitro culture and prelabeled with myo-[3H]inositol (3 microCi/ml) for 72 h. Breakdown of polyphosphoinositides was measured by using thin-layer chromatography to detect phosphatidylinositol, phosphatidylinositol 4-phosphate [PtdIns(4)P], and PtdIns(4,5)P2. Inositol phosphates were separated by ion-exchange column chromatography. The endogenous catecholamine l-epinephrine and alpha 2-adrenergic agonists clonidine and 1-(2,6-dichlorobenzylideneamino)guanidine (guanabenz) produced a rapid transient accumulation of inositol trisphosphate and inositol 4,5-bisphosphate and breakdown of [PtdIns(4)P] and PtdIns(4,5)P2. The alpha 2-adrenergic effects were not blocked by the beta-adrenergic antagonist DL-propranolol or by the alpha 1-adrenergic antagonists prazosin and methylurapidil but were inhibited by pertussis toxin and blocked by yohimbine, an alpha 2-adrenergic antagonist. The 50% effective concentration for guanabenz-stimulated inositol trisphosphate generation was right shifted from 0.3 to 0.9 microM by yohimbine. The results provide the first demonstration of alpha 2A-adrenergic activation of pertussis toxin-sensitive PtdIns(4,5)P2-dependent phospholipase C in mammalian tracheocytes. The findings are consistent with previous observations on alpha 2A-adrenergic-mediated activation of NaCl cotransport in these cells.

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