Fluorescent product formation and changes in structure of DNA reacted with peroxidizing arachidonic acid

Lipids ◽  
1973 ◽  
Vol 8 (4) ◽  
pp. 199-202 ◽  
Author(s):  
U. Reiss ◽  
L. Al Tappel
Keyword(s):  
Arachidonic Acid ◽  
Product Formation ◽  
Fluorescent Product

Pathways of Arachidonic Acid Peroxyl Radical Reactions and Product Formation with Guanine Radicals

2008 ◽  
Vol 21 (2) ◽  
pp. 358-373 ◽  
Author(s):  
Conor Crean ◽  
Nicholas E. Geacintov ◽  
Vladimir Shafirovich
Keyword(s):  
Arachidonic Acid ◽  
Peroxyl Radical ◽  
Product Formation ◽  
Radical Reactions

The effect of packed red blood cell storage on arachidonic acid and advanced glycation end-product formation

2006 ◽  
Vol 54 (5) ◽  
pp. 357-362 ◽  
Author(s):  
Lidia Łysenko ◽  
Magdalena Mierzchała ◽  
Andrzej Gamian ◽  
Grażyna Durek ◽  
Andrzej Kübler ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Product Formation ◽  
Advanced Glycation ◽  
Advanced Glycation End Product ◽  
Cell Storage

Further Studies of the Kinetics of Oxygenation of Arachidonic Acid by Soybean Lipoxygenase

1975 ◽  
Vol 53 (11) ◽  
pp. 1220-1231 ◽  
Author(s):  
H. W. Cook ◽  
W. E. M. Lands
Keyword(s):  
Experimental Data ◽  
Arachidonic Acid ◽  
Kinetic Model ◽  
Theoretical Data ◽  
Product Formation ◽  
Soybean Lipoxygenase ◽  
Product Removal ◽  
Velocity Changes ◽  
Extensive Experimental Data ◽  
Kinetics Of

A kinetic model for soybean lipoxygenase (EC 1.13.11.12) has been examined by comparing results from extensive experimental data with theoretical data generated from a computer program. Kinetic constants have been established by closely fitting experimental and computer-generated data with both product formation versus time, and the more complex accelerative and decelerative relationships of velocity changes with time.It has been confirmed that activation of lipoxygenase by its hydroperoxide product is necessary for activity, and product removal gives inhibition in a manner quantitatively predicted by the model. The earliest accurate measurement of velocity (at 9 s) is a convenient index of the amount of product–activator present in reaction mixtures, and can be used to assay quantitatively the amount of product–activator.The results confirm that soybean lipoxygenase catalyzes a product-activated, substrate-inhibited oxygenation accompanied by a self-catalyzed destruction of its activity.

scholarly journals Green and sensitive spectrofluorimetric method for the determination of two cephalosporins in dosage forms

2021 ◽  
Vol 8 (8) ◽  
pp. 210329
Author(s):  
Heba Abdel-Aziz ◽  
M. M. Tolba ◽  
N. El-Enany ◽  
F. A. Aly ◽  
M. E. Fathy
Keyword(s):  
Fluorescence Intensity ◽  
High Performance ◽  
Pharmaceutical Formulations ◽  
Product Formation ◽  
Dosage Forms ◽  
Fluorescent Product ◽  
Limit Of Quantification ◽  
Spectrofluorimetric Method ◽  
Ion Associate

Using two green and sensitive spectrofluorimetric methods, we quantified two cephalosporins, cefepime (CFM) and cefazolin (CFZ), in raw and pharmaceutical formulations. The first method is based on the reaction between CFM and fluorescamine (borate buffer, pH 8), which yields a highly fluorescent product. After excitation at 384 nm, the fluorescent product emits light at 484 nm. At concentration ranges from 12.0 to 120.0 ng ml −1 , the relative fluorescence intensity/concentration curve was linear with a limit of quantification (LOQ) of 2.46 ng ml −1 . The second method relied on measuring the CFZ quenching action on acriflavine fluorescence through formation of an ion-associate complex using Britton–Robinson buffer at pH 8. We measured acriflavine fluorescence at 505 nm after excitation at 265 nm. The decrease in acriflavine fluorescence intensity was CFZ concentration-dependent. Using this method, we quantified CFZ in concentrations ranging from 1 to 10 µg ml −1 with a LOQ of 0.48 µg ml −1 . We studied and optimized the factors influencing reaction product formation. Moreover, we adapted our methods to the investigation of the mentioned drugs in raw and pharmaceutical formulations with greatly satisfying results. We statistically validated our methods according to International Council on Harmonisation Guidelines. The obtained results were consistent with those obtained with the official high-performance liquid chromatography methods.

Increased Response to Arachidonic Acid and U-46619 and Resistance to Inhibitory Prostaglandins in Patients with Chronic Myeloproliferative Disorders

1988 ◽  
Vol 59 (01) ◽  
pp. 073-076 ◽  
Author(s):  
Sergio Cortelazzo ◽  
Monica Galli ◽  
Donatella Castagna ◽  
Piera Viero ◽  
Giovanni de Gaetano ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Myeloproliferative Disorders ◽  
Bone Marrow Stem Cell ◽  
Healthy Controls ◽  
Aggregation Response ◽  
Thrombotic Complications ◽  
Cyclic Endoperoxide ◽  
Marrow Stem Cell

SummaryIn patients with myeloproliferative disorders (MPD) a group of related diseases of the bone marrow stem cell and recurrent haemorrhagic and/or thrombotic complications, the production of aggregating prostaglandins (PGs) may be normal or slightly reduced, while PGI2 production is normal. However, MPD platelet sensitivity to antiaggregatory PGs is still unknown.We studied the potency of PGD2, PGI2 and PGEi as inhibitors of platelet aggregation induced by threshold aggregating concentrations of arachidonic acid and U-46619-analogue of the cyclic endoperoxide PGH2 in 20 patients with MPD in comparison with healthy controls, with the aim of evaluating the sensitivity of MPD platelets to antiaggregatory PGs. In these patients platelet prostanoid metabolism was normal. However, the functional response of platelets to aggregating and antiaggregating prostanoids was shifted towards potentially increased platelet aggregation response. These findings could have a clinical relevance in view of the haemostatic and thrombotic complications so frequent in MPD.

Dose-Response Aggregometry in Maternal/Neonatal Platelets

1988 ◽  
Vol 60 (02) ◽  
pp. 314-318 ◽  
Author(s):  
A M A Gader ◽  
H Bahakim ◽  
F A Jabbar ◽  
A L Lambourne ◽  
T H Gaafar ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Dose Response ◽  
Lag Phase ◽  
Phase Slope ◽  
Multiple Doses ◽  
Nonpregnant Adult ◽  
Aggregation Of Platelets

SummaryThe aggregation of platelets collected from maternal/neonatal pairs (n = 240) at the time of childbirth, was studied in response to multiple doses of ADP, collagen, arachidonic acid and ristocetin. Similar responses were obtained from healthy nonpregnant adult controls for comparison. The lag phase, slope of the aggregation curves as well as maximum aggregation (MA%) were recorded and analysed. Neonatal and adult platelets exhibited more enhanced responses to decreasing doses of ADP, arachidonic acid and ristocetin, than maternal platelets. These enhanced responses were exhibited more consistantly in the slopes of the aggregation curves than in MA%. Although neonatal platelets have shown longer lag phase in their responses to collagen, the rate of the aggregation reaction was significantly faster than maternal platelets, with no differences in MA%. These results contradict many previous reports suggesting impaired aggregation responses of neonatal platelets to these agonist. The possible reasons for these contradictions were discussed.

Involvement of Cyclooxygenase- and Lipoxygenase-Mediated Conversion of Arachidonic Acid in Controlling Human Vascular Smooth Muscle Cell Proliferation

1990 ◽  
Vol 63 (02) ◽  
pp. 291-297 ◽  
Author(s):  
Herm-Jan M Brinkman ◽  
Marijke F van Buul-Worteiboer ◽  
Jan A van Mourik
Keyword(s):  
Cell Proliferation ◽  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Muscle Cells ◽  
Smooth Muscle Cell Proliferation

SummaryWe observed that the growth of human umbilical arterysmooth muscle cells was inhibited by the phospholipase A2 inhibitors p-bromophenacylbromide and mepacrine. Thesefindings suggest that fatty acid metabolism might be integrated in the control mechanism of vascular smooth muscle cell proliferation. To identify eicosanoids possibly involved in this process, we studied both the metabolism of arachidonic acid of these cells in more detail and the effect of certain arachidonic acid metabolites on smooth muscle cells growth. We found no evidence for the conversion of arachidonic acid via the lipoxygenase pathway. In contrast, arachidonic acid was rapidly converted via the cyclooxy-genase pathway. The following metabolites were identified: prostaglandin E2 (PGE2), 6-keto-prostaglandin F1α (6-k-PGF1α), prostaglandin F2α (PGF2α), 12-hydroxyheptadecatrienoic acid (12-HHT) and 11-hydroxyeicosatetetraenoic acid (11-HETE). PGE2 was the major metabolite detected. Arachidonic acid metabolites were only found in the culture medium, not in the cell. After synthesis, 11-HETE was cleared from the culture medium. We have previously reported that PGE2 inhibits the serum-induced [3H]-thymidine incorporation of growth-arrested human umbilical artery smooth muscle cells. Here we show that also 11-HETEexerts this inhibitory property. Thus, our data suggeststhat human umbilical artery smooth muscle cells convert arachidonic acid only via the cyclooxygenase pathway. Certain metabolites produced by this pathway, including PGE2 and 11-HETE, may inhibit vascular smooth muscle cell proliferation.

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