scholarly journals Deuterated Arachidonic Acids Library for Regulation of Inflammation and Controlled Synthesis of Eicosanoids: An In Vitro Study

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3331 ◽  
Author(s):  
Dmitry Chistyakov ◽  
Ivan Filimonov ◽  
Nadezhda Azbukina ◽  
Sergei Goriainov ◽  
Viktor Chistyakov ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Kinetic Parameters ◽  
Isotope Effects ◽  
In Vitro Study ◽  
Ultra Performance Liquid Chromatography ◽  
Relative Activity ◽  
Recombinant Enzymes ◽  
Cox 2 ◽  
Arachidonic Acids

The synthesis of signal lipids, including eicosanoids, is not fully understood, although it is key to the modulation of various inflammatory states. Recently, isotopologues of essential polyunsaturated fatty acids (PUFAs) deuterated at bis-allylic positions (D-PUFAs) have been proposed as inhibitors of non-enzymatic lipid peroxidation (LPO) in various disease models. Arachidonic acid (AA, 20:4 n-6) is the main precursor to several classes of eicosanoids, which are produced by cyclooxygenases (COX) and lipoxygenases (LOX). In this study we analyzed the relative activity of human recombinant enzymes COX-2, 5-LOX, and 15-LOX-2 using a library of arachidonic acids variably deuterated at the bis-allylic (C7, C10, and C13) positions. Kinetic parameters (KM, Vmax) and isotope effects calculated from kH/kD for seven deuterated arachidonic acid derivatives were obtained. Spectroscopic methods have shown that deuteration at the 13th position dramatically affects the kinetic parameters of COX-2 and 15-LOX-2. The activity of 5-LOX was evaluated by measuring hydroxyeicosatetraenoic acids (8-HETE and 5-HETE) using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Deuteration at the seventh and 10th positions affects the performance of the 5-LOX enzyme. A flowchart is proposed suggesting how to modulate the synthesis of selected eicosanoids using the library of deuterated isotopologues to potentially fine-tune various inflammation stages.

Activity of dipyrone on intraplatelet arachidonic acid metabolism: An in vitro study

1989 ◽  
Vol 21 (1) ◽  
pp. 43-50 ◽  
Author(s):  
R ABBATE ◽  
S PINTO ◽  
A GORI ◽  
R PANICCIA ◽  
M COPPO ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Acid Metabolism ◽  
In Vitro Study ◽  
Arachidonic Acid Metabolism ◽  
Vitro Study

Arachidonic acid supplementation enhances in vitro skeletal muscle cell growth via a COX-2-dependent pathway

2013 ◽  
Vol 304 (1) ◽  
pp. C56-C67 ◽  
Author(s):  
James F. Markworth ◽  
David Cameron-Smith
Keyword(s):  
Skeletal Muscle ◽  
Arachidonic Acid ◽  
Cell Growth ◽  
Muscle Cell ◽  
Myogenic Differentiation ◽  
Skeletal Muscle Cell ◽  
Diverse Range ◽  
Cox 2 ◽  
Dependent Pathway

Arachidonic acid (AA) is the metabolic precursor to a diverse range of downstream bioactive lipid mediators. A positive or negative influence of individual eicosanoid species [e.g., prostaglandins (PGs), leukotrienes, and hydroxyeicosatetraenoic acids] has been implicated in skeletal muscle cell growth and development. The collective role of AA-derived metabolites in physiological states of skeletal muscle growth/atrophy remains unclear. The present study aimed to determine the direct effect of free AA supplementation and subsequent eicosanoid biosynthesis on skeletal myocyte growth in vitro . C2C12 (mouse) skeletal myocytes induced to differentiate with supplemental AA exhibited dose-dependent increases in the size, myonuclear content, and protein accretion of developing myotubes, independent of changes in cell density or the rate/extent of myogenic differentiation. Nonselective (indomethacin) or cyclooxygenase 2 (COX-2)-selective (NS-398) nonsteroidal anti-inflammatory drugs blunted basal myogenesis, an effect that was amplified in the presence of supplemental free AA substrate. The stimulatory effects of AA persisted in preexisting myotubes via a COX-2-dependent (NS-389-sensitive) pathway, specifically implying dependency on downstream PG biosynthesis. AA-stimulated growth was associated with markedly increased secretion of PGF2α and PGE2; however, incubation of myocytes with PG-rich conditioned medium failed to mimic the effects of direct AA supplementation. In vitro AA supplementation stimulates PG release and skeletal muscle cell hypertrophy via a COX-2-dependent pathway.

Sex Difference In Platelet Response To Aspirin Treatment

1981 ◽  
Author(s):  
N S Nicholson ◽  
S L Smith ◽  
R N Saunders
Keyword(s):  
Arachidonic Acid ◽  
Sex Difference ◽  
In Vitro Study ◽  
Female Rats ◽  
Platelet Response ◽  
Male And Female Rats ◽  
Males And Females ◽  
Spontaneous Aggregation

This study was done to determine if a sex difference in response to aspirin similar to that seen in the clinic could be demonstrated in an animal model with hyperactive platelets. The platelet hyperactivity which results in the spontaneous formation of platelet aggregates in retired breeder rats was reduced in both male and female rats by sulfinpyrazone, dipyridamole and indomethacin administered at 20 mg/kg. Aspirin blocked spontaneous aggregation in the male, but had no effect in the female even at doses of 100 mg/kg. Because aspirin is known to be an inhibitor of cyclooxygenase, the metabolism of arachidonic acid was studied in these rats. Arachidonic acid at 20 mg/kg was active in reducing spontaneous aggregation in the male, but had no effect in the female. However, in an in vitro study of the metabolism of arachidonic acid, no significant differences were seen between males and females in the conversion of arachidonic acid to PGF2α, PGE2, TXB2 or HHT. Aspirin was equally effective in both males and females in blocking the in vitro conversion of arachidonic acid via the cyclooxygenase pathway. The retired breeder rat provides a system for meaningful investigations toward understanding the human sex-related differences in platelet sensitivity with aspirin, although the mechanisms of the in vivo male/female platelet sensitivity have not been explained by in vitro studies thus far.

Propofol Potentiates Phenylephrine-induced Contraction via  Cyclooxygenase Inhibition in Pulmonary Artery Smooth Muscle

2001 ◽  
Vol 94 (5) ◽  
pp. 833-839 ◽  
Author(s):  
Koji Ogawa ◽  
Satoru Tanaka ◽  
Paul A. Murray
Keyword(s):  
Arachidonic Acid ◽  
Smooth Muscle ◽  
In Vitro Study ◽  
Isometric Tension ◽  
Relaxation Response ◽  
Response Curves ◽  
Independent Manner ◽  
Pulmonary Arterial

Background The authors previously demonstrated in vivo that the pulmonary vasoconstrictor response to the a agonist phenylephrine is potentiated during propofol anesthesia compared with the conscious state. The current in vitro study tested the hypothesis that propofol potentiates phenylephrine-induced contraction by inhibiting the synthesis and/or activity of vasodilator metabolites of the cyclooxygenase pathway. Methods Canine pulmonary arterial rings were suspended for isometric tension recording. Intracellular calcium concentration ([Ca2+]i) was measured in pulmonary arterial strips loaded with acetoxylmethyl ester of fura-2. After phenylephrine-induced contraction, propofol (10(-7) to 10(-4) M) was administered in the presence or absence of the cyclooxygenase inhibitor ibuprofen (10(-5) M). The effects of propofol on the arachidonic acid and prostacyclin relaxation-response curves were assessed. The amount of 6-keto prostaglandin F1alpha (stable metabolite of prostacyclin) released from pulmonary vascular smooth muscle in response to phenylephrine was measured with enzyme immunoassay in the presence or absence of propofol and ibuprofen. Results Propofol potentiated phenylephrine-induced contraction in pulmonary arterial rings in a concentration-dependent and endothelium-independent manner. In endothelium-denuded strips, propofol (10(-4) M) increased tension by 53+/-11%, and increased [Ca2+]i by 56+/-9%. Ibuprofen also potentiated phenylephrine-induced contraction but abolished the propofol-induced increases in tension and [Ca2+]i. Propofol had no effect on the relaxation response to prostacyclin, whereas propofol and ibuprofen attenuated the relaxation response to arachidonic acid to a similar extent. Phenylephrine markedly increased 6-keto prostaglandin F1alpha production, and this effect was virtually abolished by propofol and ibuprofen. Conclusion These results suggest that propofol potentiates alpha-adrenoreceptor-mediated pulmonary vasoconstriction by inhibiting the concomitant production of prostacyclin by cyclooxygenase.

Modulation by Dipyridamole of the Arachidonic Acid Metabolic Pathway in Platelets an in vivo and in vitro Study

1979 ◽  
Author(s):  
Neri G.G. Serneri ◽  
G. F. Gensini ◽  
R. Abbate ◽  
S. Favilla ◽  
R. Laureano
Keyword(s):  
Arachidonic Acid ◽  
Antiplatelet Agent ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Oral Route ◽  
Radiometric Assay ◽  
Venous Infusion ◽  
Clinical Conditions

Dipyridamole is a useful antiplatelet agent in specific clinical conditions, but its effects on TxEL production by platelets are now being debated, Resting platelets from patients with 1.5-2 fig/ml serum dipyridamole (spectrofluorimetric assay). administered by venous infusion or by oral route, showed an increased concentration (m.v. +60% P<0.001) of cAMP (radiometric assay). After stimulation with thrombin (5U/ml) platelets produced a significantly decreased amount of TxB(m.v. -60%, F< 0.001) (radioimmunoassay with antibody kindly supplied by Doctor J.B. Smith, Philadelphia). However also after stimulation with arachidonic acid (A.A.) 1 mM TxB production was decreased(m.v. -50%, P<0.001). The incubation of control platelets with different concentrations of dipyridamole (0.5, 1 and 2 μg/ml) for 20 min at 37°C resulted in an increase of cAMP and in a decrease of TxB, production after stimulation with thrombin and with A.A.. These results indicate that dipyridamole is endowed with direct antiaggrega= ting activity caused by a decreased production of TxB2. This in tum seems due to an inhibitory modulating effect of cAMP on arachidonic acid cyclo-oxygenation. However our findings do not rule out an inhibitory effect also on phospholipase A2.

scholarly journals Preparation and Characterization of Polyamidoamine G2.0-Hematin as a Biocatalyst for Fabricating Catecholic Gelatin Hydrogel

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Tan Phuoc Ton ◽  
Thi Yen Nhi Tran ◽  
Le Hang Dang ◽  
Kim Thi Hoang Nguyen ◽  
Phuong Doan ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
In Vitro Study ◽  
Pamam Dendrimer ◽  
Relative Activity ◽  
Oxidation Reactions ◽  
Enzyme Mimicking ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In this study, we report that an enzyme-mimicking biocatalyst polyamidoamine (PAMAM) dendrimer G2.0-hematin (G2.0-He) was fabricated successfully. The chemical structure of G2.0-He was verified by 1H NMR and FT-IR spectroscopy. G2.0-He exhibited a size distribution from 11.6 ± 1.7   nm to 12.5 ± 2.9   nm and a zeta potential from 32.5 mV to 25.6 mV along with the enhancement of the hematin conjugation degree. The relative activity of G2.0-He was evaluated based on pyrogallol oxidation reactions at pH = 7 . The results showed that G2.0-He was more stable than horseradish peroxidase (HRP) enzyme in high H2O2 concentrations. The HRP-mimic ability of G2.0-He was also confirmed by the catalyzation when preparing catecholic gelatin hydrogels under mild conditions. Moreover, our results also revealed that these hydrogels performed with excellent cytocompatibility in an in vitro study and could be used as a potential scaffold for adhesion and proliferation of fibroblast cells. The obtained results indicated that G2.0-He is a suitable platform for altering the HRP enzyme in several biomedical applications.

scholarly journals Elevated levels of arachidonic acid metabolites in follicular fluid of PCOS patients

Reproduction ◽  
2020 ◽  
Vol 159 (2) ◽  
pp. 159-169 ◽  
Author(s):  
Shengxian Li ◽  
Jia Qi ◽  
Yongzhen Tao ◽  
Qinling Zhu ◽  
Rong Huang ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Follicular Fluid ◽  
Polycystic Ovary ◽  
Reproductive Age ◽  
Pathophysiological Mechanism ◽  
Obese Women ◽  
Liquid Chromatography Mass Spectrometry ◽  
Acid Metabolites ◽  
Cox 2

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-age women usually accompanied by lipid metabolic disorders. However, it remains unknown whether arachidonic acid (AA) and its metabolites in follicular fluid (FF) were altered in PCOS patients. This study was intended to measure the levels of AA and its metabolites in the FF of non-obese PCOS patients that underwent in vitro fertilization (IVF) and to explore the possible causes of the alterations. Thirty-nine non-obese women with PCOS and 30 non-obese women without PCOS were enrolled. AA and its metabolites were measured by liquid chromatography-mass spectrometry. The levels of AA metabolites generated via cyclooxygenase-2 (COX-2) pathway and cytochrome P450 epoxygenase pathway but not lipoxygenase (LOX) pathway were significantly higher in the FF of PCOS patients. The metabolites generated via COX-2 pathway were significantly correlated with levels of testosterone and fasting insulin in serum. The in vitro study further demonstrated that insulin but not testosterone could promote the IL-1β and hCG-induced COX-2 expression and prostaglandin E2 (PGE2) secretion in primary human granulosa cells. In conclusion, there was an elevation in AA metabolites in FF of PCOS patients. Insulin played a pivotal role in the increased AA metabolites generated via COX-2, which could be interpreted as another novel molecular pathophysiological mechanism of PCOS.

Chemopreventive potential of selective cyclooxygenase-2 (COX-2) inhibition in Barrett's epithelium: An in vitro study

2000 ◽  
Vol 118 (4) ◽  
pp. A35 ◽  
Author(s):  
Navtej S. Buttar ◽  
Marlys A. Anderson ◽  
Krishnawatie K. Krishnadath ◽  
Lori S. Lutzke ◽  
Pardeep K. Nijhawan ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Cyclooxygenase 2 ◽  
Vitro Study ◽  
Barrett’S Epithelium ◽  
Cox 2 ◽  
Barrett's Epithelium

In vitro exhaustion of pancreatic beta-cells

1986 ◽  
Vol 250 (5) ◽  
pp. E502-E511 ◽  
Author(s):  
M. Hoenig ◽  
L. C. MacGregor ◽  
F. M. Matschinsky
Keyword(s):  
Amino Acids ◽  
Arachidonic Acid ◽  
Pancreatic Beta Cells ◽  
Basal Medium ◽  
In Vitro Study ◽  
Bicarbonate Buffer ◽  
Isolated Pancreatic Islets ◽  
Perifusion System ◽  
Secretory Capacity

To learn more about possible limited beta-cell secretory capacity and factors essential for insulin release, a perifusion system was applied that allowed the in vitro study of insulin secretion from isolated pancreatic islets for more than 6 h. Islets isolated from rats were stimulated with various glucose concentrations (7.5, 16.7, and 30 mM), alpha-ketoisocaproate (30 mM), and 30 mM glucose plus 1 mM 3-isobutyl-1-methylxanthine for several hours in Krebs-Ringer-bicarbonate buffer (KRB) or RPMI 1640. Islets showed "exhaustion" with all stimulatory conditions used when KRB was the perifusion medium. This was not prevented by addition of amino acids, phosphate, myo-inositol or arachidonic acid. With RPMI 1640 as the basal medium, exhaustion was not seen at 7.5 mM but was readily approached at higher glucose concentrations. It is possible that the exhaustion phenomenon observed here is due to a depletion of a readily releasable insulin pool.

Sign in / Sign up

Export Citation Format

Share Document