Cholestérol et pathologies oculaires : focus sur le rôle de la cholestérol 24S-hydroxylase (CYP46A1) dans l’homéostasie du cholestérol

Resume La retine est le tissu neurosensoriel de l’œil qui assure la transduction visuelle, c’est-a-dire le codage de l’information lumineuse en influx nerveux. Le terme « retine » regroupe l’association de la retine neurale et de l’epithelium pigmentaire retinien qui repose sur la membrane de Bruch. L’association physique de ces deux partenaires et leurs interactions metaboliques sont des elements indispensables au bon fonctionnement de la retine, a la fois en termes d’apport en nutriments et de maintien de l’homeostasie. Des dereglements de ces equilibres sont associes au vieillissement et a des pathologies comme la degenerescence maculaire liee a l’âge, premiere cause de malvoyance apres …

Cholestérol et pathologies oculaires

Contribution à l’étude de la fraction insaponifiable de trois huiles d’olive issues des variétés Guasto, Rougette et Blanquette plantés dans l’est algérien

The sterol profile of three Algerian virgin olive oils produced from Guasto, Blanquette and Rougette cultivar’s, varieties grown in the East of the country, was established by gas chromatography using a flame ionization detector and coupled to mass spectrometry. Four sterol compounds were identified and characterized in the three oils which are, sitosterol always predominant (43-66%), delta 5-avenasterol (8-13%), stigmasterol (≤ 1,5%) and campesterol (1-2%); one methyl sterol (4-methylsterol) : citrostadienol (4-7%) and two triterpenic alcohols : 24-methylene cycloartanol (10-33%) and cycloartenol (3-13%). These results vary according to campany and variety. Our study shows that most of the…

Diversity of Sterol Composition in Tunisian Pistacia lentiscus Seed Oil

International audience; Pistacia lentiscus L. seed oil is used in some Mediterranean forest area for culinary and medicinal purposes. In this study, we aim to examine, for the first time, the effect of growing area on sterol content of Pistacia lentiscus seed oil. Fruits were harvested from 13 different sites located in northern and central Tunisia. Gas chromatography-flame-ionization detection (GC-FID) was used to quantify sterols and gas chromatography/mass spectrometry (GC/MS) was used to identify them. The major sterol identified was b-sitosterol with a value ranging from 854.12 to 1224.09 mg/kg of oil, thus making up more than 54% of the total sterols. The other two main sterols were c…

Lymphatic Delivery and In Vitro Pancreatic Lipase Hydrolysis of Glycerol Esters of Conjugated Linoleic Acids in Rats

We examined the intestinal delivery of conjugated linoleic acids (CLA) given in their triacylglycerol form in the mesenteric lymph of rats. Emulsions containing a mixture of the trilinolein/triester of CLA (9:1) and a tri-[1-(14)C]-linoleyl-sn-glycerol tracer were administered by force-feeding. Lymph was collected over two time periods (0-6 and 6-24 h), and the apparent recovery of CLA was determined relative to that of [1-(14)C]-18:2(n-6). A mixture of CLA-triester/trilinolein (1:9), trilinolein or CLA-triester was separately subjected to pancreatic lipase hydrolysis in vitro to determine whether the lymphatic recovery of CLA was correlated with the initial step of digestion. Lymphatic rec…

Effects of 24s-hydroxycholesterol on primary glial Müller cells. New insights on Müller cells function and cholesterol homeostasis in the retina

Purpose: Müller cells are macroglial cells in the retina. These cells express various proteins known to undergo glutamate clearance, which dysfunction may be involved in the loss of retinal ganglion cells (RGC) in the course of glaucoma. In neurons and especially in RGC, 24S-hydroxycholesterol (24SOH) is a metabolite produced by conversion of cholesterol by cholesterol 24S-hydroxylase (CYP46A1). This process participates to cholesterol homeostasis by facilitating the removal of cholesterol from neurons. 24SOH might be a signal molecule ensuring the cross-talk between neurons and glia, and putatively between RGC and glia. The aim of our study was to emphasize the response of primary Müller c…

Causal Link between n-3 Polyunsaturated Fatty Acid Deficiency and Motivation Deficits

International audience; Reward-processing impairment is a common symptomatic dimension of several psychiatric disorders. However, whether the underlying pathological mechanisms are common is unknown. Herein, we asked if the decrease in the n-3 polyunsaturated fatty acid (PUFA) lipid species, consistently described in these pathologies, could underlie reward-processing deficits. We show that reduced n-3 PUFA biostatus in mice leads to selective motivational impairments. Electrophysiological recordings revealed increased collateral inhibition of dopamine D2 receptor-expressing medium spiny neurons (D2-MSNs) onto dopamine D1 receptor-expressing MSNs in the nucleus accumbens, a main brain regio…

Cholesterol and ocular pathologies: focus on the role of cholesterol-24S-hydroxylase in cholesterol homeostasis

The retina is responsible for coding the light stimulus into a nervous signal that is transferred to the brain via the optic nerve. The retina is formed by the association of the neurosensory retina and the retinal pigment epithelium that is supported by Bruch’s membrane. Both the physical and metabolic associations between these partners are crucial for the functioning of the retina, by means of nutrient intake and removal of the cell and metabolic debris from the retina. Dysequilibrium are involved in the aging processes and pathologies such as age-related macular degeneration, the leading cause of visual loss after the age of 50 years inWestern countries. The retina is composed of severa…

Impact of dietary fatty acids on autophagy in the retina

In vivo consequences of cholesterol-24s-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina

Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol in neurons and participates in cholesterol homeostasis in the central nervous system, including the retina. We aimed to evaluate the consequences of CYP46A1 inhibition by voriconazole on cholesterol homeostasis and function in the retina. Rats received daily intraperitoneal injections of voriconazole (60mg/kg), minocycline (22mg/kg), voriconazole plus minocycline, or vehicle during five consecutive days. The rats were submitted to electroretinography to monitor retinal functionality. Cholesterol and 24S-hydroxycholesterol were measured in plasma, brain and retina by gas chromatography-mass spectrometry. T…

Gangliosides in the retina: a comparative inventory with brain and other ocular structures

International audience

Identification of a circulating biomarker highly associated to retinal omega-3 polyunsaturated fatty acid content: the BLISAR project

International audience

24-(S)-hydroxycholesterol is a potent modulator of cholesterol metabolism in rat retinal Müller glia

International audience

A novel murine model of aging of the human retina

Purpose Accumulation of lipids, and especially of cholesteryl esters, under the retinal pigment epithelium and within Bruch’s membrane is a normal feature of aging and has also been observed in human eyes with age-related maculopathy. Our objective was to evaluate the retinal phenotype of apoB100,LDLR-/- mice, a model for lipid metabolism dysfunction and potentially of aging of the retina. Methods ApoB100,LDLR-/- mice were studied at 7 and 14 months of age by standard scotopic and photopic electroretinography by comparison to control animals. Fundus images were obtained with a confocal SLO (Heidelberg Retina Angiograph). The integrity of the vascular system was investigated by means of fluo…

Association of a predictor of retinal omega-3 polyunsaturated fatty acids with advanced age-related macular degeneration: the BLISAR project

International audience

In vivo consequences of cholesterol-24S-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina

International audience; Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol in neurons and participates in cholesterol homeostasis in the central nervous system, including the retina. We aimed to evaluate the consequences of CYP46A1 inhibition by voriconazole on cholesterol homeostasis and function in the retina. Rats received daily intraperitoneal injections of voriconazole (60 mg/kg), minocycline (22 mg/kg), voriconazole plus minocycline, or vehicle during five consecutive days. The rats were submitted to electroretinography to monitor retinal functionality. Cholesterol and 24S-hydroxycholesterol were measured in plasma, brain and retina by gas chromatog…

ApoB100,LDLR-/- mice exhibit reduced electroretinographic response and cholesteryl esters deposits in the retina

International audience; PURPOSE. To evaluate the retinal phenotype of 7- and 14-month-old apoB100,LDLR–/– mice, a relevant animal model of lipid metabolism dysfunction. METHODS. Single-flash electroretinograms were obtained from 7- and 14-month-old apoB100,LDLR–/– and control mice fed a standard diet under both scotopic and photopic conditions. Visual cycle retinoids were analyzed in eyes from dark-adapted mice. Retinal and choroidal vascularization was evaluated with scanning laser ophthalmoscopy. Fatty acids were analyzed in the retina. Esterified and free cholesterol was detected in eye cryosections. RESULTS. Scotopic and photopic b-wave amplitudes were significantly reduced in apoB100,L…

Apprehending ganglioside diversity: a comprehensive methodological approach

Gangliosides make a wide family of glycosphingolipids ubiquitously expressed in mammalian tissues and particularly abundant in the brain and nervous system. They exhibit a huge diversity due to structural variations in both their oligosaccharidic chain and ceramide moiety, which represent a real analytical challenge. Since their discovery in the 1940s, methods have persistently improved until the emergence of Liquid Chromatography/Mass Spectrometry (LC/MS) which offers a high level of specificity and sensitivity and is suitable with high-throughput profiling studies. We describe here a comprehensive approach relying on various techniques and aiming at fully characterizing gangliosides in bi…

Cholesterol homeostasis and retinal stress in anterior ischemic optic neuropathy

Purpose: Anterior ischemic optic neuropathy (AION) is characterized by acute stress of retinal ganglion cells (RGC). Cholesterol-24S-hydroxylase (CYP46A1) is specifically expressed in RGC where it may exert neuroprotective properties by preventing from cholesterol accumulation via catalyzing the formation of 24S-hydroxycholesterol. Previous findings hypothesize the housekeeping importance of CYP46A1 in the maintenance of cholesterol in the retina. In order to better understand the role of CYP46A1 in the retina, we aimed to define whether CYP46A1 expression and 24S-hydroxycholesterol levels were modified during RGC stress in AION.Methods: Ninety nine male Sprague Dawley rats were randomized …

Analysis of pecan nut ([i]Carya illinoinensis[/i]) unsaponifiable fraction. Effect of ripening stage on phytosterols and phytostanols composition

Changes in 4-desmethylsterol, 4-monomethylsterol, 4,4-dimethylsterol and phytostanol composition were quantitatively and qualitatively investigated during the ripening of three varieties of Tunisian-grown pecan nuts (Mahan, Moore and Burkett). These components have many health benefits, especially in lowering LDL-cholesterol and preventing heart disease. The phytosterol composition of whole pecan kernel was quantified by Gas Chromatography-Flame Ionisation Detection (GC-FID) and identified by Gas Chromatography-Mass Spectrometry (GC-MS). Fifteen phytosterols and one phytostanol were quantified. The greatest amount of phytosterols (2852.5 mg/100 g of oil) was detected in Mahan variety at 20 …

Oxysterols Incorporate in Primary Porcine Retinal Pigment Epithelial Cells and Induce Inflammation and Oxidative Stress

International audience; Purpose: : Aging is associated with an accumulation of cholesterol in the Bruch’s membrane. Cholesterol is prone to undergo oxidation and to generate oxysterols that have cytotoxic properties. The aim of this study was to evaluate the effects of oxysterols on cell viability, oxidative stress and inflammation and to measure oxysterol incorporation in primary porcine retinal pigment epithelial (RPE) cell cultures. Methods: : Porcine RPE cells were incubated with oxysterols (24S–hydroxycholesterol, 24OH ; 25–hydroxycholesterol, 25OH and 7–ketocholesterol, 7K) (100µg, 50µM) for 24 and 48h. Cell viability was evaluated by measuring mitochondrial succinate dehydrogenase (S…

Long-term intake of Lacticaseibacillus helveticus enhances bioavailability of omega-3 fatty acids in the mouse retina

Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), are required for the structure and function of the retina. They could also help to prevent or delay the development of retinopathies. Given the accumulating evidence showing the role of gut microbiota in regulating retinal physiology and host lipid metabolism, we evaluated the potential of long-term dietary supplementation with the Gram-positive bacterium Lacticaseibacillus helveticus strain VEL12193 to modulate the retinal n-3 PUFA content. A set of complementary approaches was used to study the impact of such a supplementation on the gut microbiota and host lipid/fatty acid (FA) metabolism. L. helv…

Encapsulation de la lutéine et du DHA sous forme d’émulsions sèches : intérêt pour les pathologies rétiniennes

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Bioavailability of dietary omega-3 DHA and lutein for the retina: results from a preclinical study in mini-pigs with encapsulated nutrients

Purpose: Epidemiological studies support the hypothesis that dietary omega-3 long chain polyunsaturated fatty acids and carotenoids prevent from Age-related Macular Degeneration (AMD). AREDS2 failed to find benefits of omega-3 supplementation on the progression to advanced AMD. However, lower risk progression was reported in AMD patients of the NAT2 study whom omega-3 incorporation in red blood cells and plasma was the highest. Our purpose was to test whether feeding mini-pigs with encapsulated docosahexaenoic acid (DHA) and lutein would promote the bioavailability of the nutrients in plasma and tissues including the retina. Methods: Microparticles containing lutein and DHA were formed by s…

Lipid composition of the human eye: are red blood cells a good mirror of retinal and optic nerve fatty acids?

International audience; BACKGROUND: The assessment of blood lipids is very frequent in clinical research as it is assumed to reflect the lipid composition of peripheral tissues. Even well accepted such relationships have never been clearly established. This is particularly true in ophthalmology where the use of blood lipids has become very common following recent data linking lipid intake to ocular health and disease. In the present study, we wanted to determine in humans whether a lipidomic approach based on red blood cells could reveal associations between circulating and tissue lipid profiles. To check if the analytical sensitivity may be of importance in such analyses, we have used a do…

Acides gras polyinsaturés de la rétine : ont-ils une origine alimentaire ? Lipid Nutri+

National audience; L’objectif du présent article est de faire le point sur l’origine des acides gras polyinsaturés dans la rétine neurale, en se focalisant en particulier sur le DHA. Nous appuierons notre propos en particulier sur nos données récentes obtenues sur des sujets décédés chez qui la rétine neurale et le couple EPR/choriocapillaire ont été prélevés et analysés pour leur contenu en lipides. Le profil en acides gras du tissu adipeux nous a servi de marqueur de consommation. Nous avons ainsi pu rechercher si les teneurs en AGPI de la rétine neurale sont le reflet des habitudes alimentaires des sujets.

Characterization of membrane structure modifications induced during plant defense signaling

SPEIPMUBINRADOCT; Plasma membrane was long considered as a simple separation between internal and external cellular environment. But more, it is a dynamic interface, an exchange platform. Now, recent researches highlight its role in plant defense responses to biotic and abiotic stresses. We use the tobaccocryptogein model to study the early steps of plant cell responses to pathogen detection. The signaling cascade includes an oxidative burst triggering an increase of plasma membrane order. The level of membrane order informs us about both packing and arrangement of membrane components, this parameter being evaluated by spectrofluorimetric approaches using a lipidic environment-sensitive pro…

4812 - A0028 Gangliosides in the retina: a comparative inventory with brain and other ocular structures

Purpose: Gangliosides (GG) make an extremely diverse family of glycosphingolipids particularly abundant in the brain and neural tissues. While it is known that alterations in GG metabolism are associated with visual defects, the precise biological roles of these compounds in the retina are still largely unknown. In this context, we performed an exhaustive inventory and thorough characterization of the human eye GG aiming to reveal specificities and common features of the retina compared to other ocular tissues and brain.Methods: Retina, RPE/Choroid, ciliary body, optic nerve and brain samples were collected from deceased human donors (N=7). GG were extracted and analysed by a comprehensive …

Validation of the use of a circulating biomarker of retinal omega-3 polyunsaturated fatty acids in supplementation conditions: the BLISAR project

Identification and quantification of phosphatidylcholines containing very-long-chain polyunsaturated fatty acid in bovine and human retina using liquid chromatography/tandem mass spectrometry.

The retina is one of the vertebrate tissues with the highest content in polyunsaturated fatty acids (PUFA). A large proportion of retinal phospholipids, especially those found in photoreceptor membranes, are dipolyunsaturated molecular species. Among them, dipolyunsaturated phosphatidylcholine (PC) molecular species are known to contain very-long-chain polyunsaturated fatty acids (VLC-PUFA) from the n-3 and n-6 series having 24-36 carbon atoms (C24-C36) and four to six double bonds. Recent interest in the role played by VLC-PUFA arose from the findings that a protein called elongation of very-long-chain fatty acids 4 (ELOVL4) is involved in their biosynthesis and that mutations in the ELOVL…

Profile of Fatty Acids, Tocopherols, Phytosterols and Polyphenols in Mediterranean Oils (Argan Oils, Olive Oils, Milk Thistle Seed Oils and Nigella Seed Oil) and Evaluation of their Antioxidant and Cytoprotective Activities

Background: The effects of vegetable oils on human health depend on their components. Therefore, their profiles of lipid nutrients and polyphenols were determined. Objective: To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO; Morocco, Spain, Tunisia); milk thistle seed oils (MTSO; Tunisia: Bizerte, Sousse, Zaghouane); nigella seed oil (NSO). Methods: The biochemical profiles were determined by gas chromatography-flame ionization, high performance liquid chromatography and gas chromatography, coupled with mass spectrometry as required. The antioxidant …

Modulation of lipid membrane organization of Müller Glial Cells (MGC) by 24-(S)-hydroxycholesterol (24-S-OHC) in glaucoma

Modulation of lipid membrane organization of Müller Glial Cells (MGC) by 24-(S)-hydroxycholesterol (24-S-OHC) in glaucoma. Session 3: Nutrition and oxysterols biological activities. ENOR Symposium

Docosahexaenoic acid protects human RPE cells against oxidative stress via PI3K/Akt m-TOR/p70-p85S6K pathways

Purpose Oxidative Stress (OS) plays a critical role in the pathogenesis of age-related macular degeneration (AMD), especially by targeting the retinal pigment epithelium (RPE). Dietary habits with high consumption of docosahexaenoic acid (DHA) have been shown to prevent the development and evolution of AMD. Nevertheless, it is still unclear how DHA affects AMD. Our study aimed to investigate the involvement of the PI3K/Akt and m-TOR/p70-p85S6K pathways in human RPE cells after induction of OS, and then to assess the effect of DHA in the signaling pathways and in the protection against RPE cell death. Methods For this purpose, we used ARPE-19 cells exposed to the prooxidant agent, tert-butyl…

Effect of growing area on tocopherols, carotenoids and fatty acid composition ofPistacia lentiscusedible oil

International audience; In this investigation, we aim to study, for the first time, the effect of the growing area on tocopherols, carotenoids and fatty acid content of Pistacia lentiscus fixed oil. Fruits were harvested from eight different sites located in the north and the centre of Tunisia. Tocopherols, carotenoids and fatty acid content of the fixed oils were determined. The highest carotenoid content was exhibited by Feija oil (10.57 mg/kg of oil). Oueslatia and Tabarka oils displayed the highest alpha-tocopherol content (96.79 and 92.79 mg/kg of oil, respectively). Three major fatty acids were determined: oleic, palmitic and linoleic acids. Oleic acid was the main fatty acid presenti…

Cholesterol homeostasis and retinal stress in anterior ischemic optic neuropathy

International audience

Age-Related Changes in the Gut Microbiota Modify Brain Lipid Composition

PMCID: PMC6970973; International audience; Understanding the molecular mechanisms underlying the changes observed during aging is a prerequisite to design strategies to prevent age-related diseases. Aging is associated with metabolic changes, including alteration in the brain lipid metabolism. These alterations may contribute to the development of pathophysiological conditions. Modifications in the gut microbiota composition are also observed during aging. As communication axes exist between the gut microbiota and the brain and knowing that microbiota influences the host metabolism, we speculated on whether age-associated modifications in the gut microbiota could be involved in the lipid ch…

Characterization of cholesterol metabolism in an experimental model of glaucoma in rats

International audience; Glaucoma is a neurodegenerative pathology characterized by retinal ganglion cell death. Cholesterol homeostasis disruption has been implicated in several neurodegenerative diseases such as Alzheimer and Huntington. However, its specific role in the retina and association with glaucoma remain unclear. The aim of this study was to characterize the modifications of cholesterol metabolism occurring during an experimental model of glaucoma in rats. Eight-weeks old male rats were subjected to laser photocoagulation of episcleral veins, limbus and trabecular meshwork to elevate intraocular pressure. At a short (3 days) and a long (2 months) time period post-laser, the retin…

Plasmalogen levels are reduced in erythrocytes from patients with diabetic retinopathy

Plasmalogen levels are reduced in erythrocytes from patients with diabetic retinopathy. annual meeting of the association-for-research-in-vision-and-ophthalmology (ARVO)

Identification and quantification of phosphatidylcholines containing very long chain polyunsaturated fatty acid (VLC-PUFA) in bovine and human retina by liquid chromatography/tandem mass spectrometry

The retina is one of the vertebrate tissues with the highest content in polyunsaturated fatty acids (PUFA). A large proportion of the retinal glycerophospholipids, especially those found in photoreceptor membranes, are dipolyunsaturated molecular species. Among them, dipolyunsaturated phosphatidylcholine molecular species are known to contain very long chain polyunsaturated fatty acids (VLC-PUFA) from the n-3 and n-6 series and having 24 to 36 carbon atoms (C24 to C36) and four to six double bonds. Recent interest in the role of VLC-PUFA arose from the findings that a protein named ELOngation of Very Long chain fatty acids 4 (ELOVL4) is involved in their biosynthesis and that mutations in E…

Absence of oxysterol-like side effects in human monocytic cells treated with phytosterols and oxyphytosterols

Oxysterols, found in some commonly consumed foods, can induce a wide range of cytotoxic effects, which have been extensively studied. On the other hand, the side effects of phytosterols and oxyphytosterols are less well-known. Over the past few years, different types of foods have been enriched with phytosterols on the basis of the properties of these compounds that reduce circulating cholesterol levels in certain experimental conditions. It is therefore important to gain better knowledge of the risks and benefits of this type of diet. In this study, conducted in human monocytic U937 cells, the ability of phytosterols (sitosterol, campesterol) and oxyphytosterols (7 beta-hydroxysitosterol, …

Steady-state levels of retinal 24S-hydroxycholesterol are maintained by glial cells intervention after elevation of intraocular pressure in the rat

Purpose: Our previous studies suggested that CYP46A1 and 24S-hydroxycholesterol. (24SOH) may be associated with glaucoma. Loss of CYP46A1-expressing retinal. ganglion cells is involved in the activation of glia, and therefore possibly in the. disbalance of cholesterol. In this context, the purpose of our present work was to. emphasize the glial and longitudinal CYP46A1 expression after an interventional. glaucoma-related stress triggered by elevated intraocular pressure (IOP). Methods: Sprague–Dawley rats were submitted to laser photocoagulation of the. trabecular meshwork, limbus and episcleral veins in one eye to induce elevated IOP. Rats were euthanized at days 3, 14, 30 and 60 (n = 10 p…

Identification and quantitation of tocopherols, carotenoids and triglycerides in edible Pistacia lentiscus oil from Tunisia

International audience; The fruits of Pistacia lentiscus are a source of a fixed oil used in some forested areas for culinary purposes and in traditional medicines. The aim of this study was to evaluate the levels of tocopherols, carotenoids and triglycerides in this oil using high-performance liquid chromatography (HPLC). The results demonstrated the presence of two vitamin E isomers; α- and γ-tocopherols, at respective concentrations of 119 mg and 23 mg per kg of oil. β-carotene, lutein and zeaxanthin were the principal carotenoid molecules identified. β-carotene was the main molecule present, with a level of 6.13 mg/kg oil. Di-unsaturated triglycerides comprised more than half of the tot…

Oxyphytosterols are present in plasma of healthy human subjects

The oxidised derivatives of phytosterols (oxyphytosterols) were identified in plasma samples from thirteen healthy human volunteers, using MS. All the samples contained noticeable quantities of (24R)-5b,6b-epoxy-24-ethylcholestan-3b-ol (b-epoxysitostanol) and (24R)-ethylcholestan-3b,5a,6b-triol (sitostanetriol) and also trace levels of (24R)-5a,6a-epoxy-24-ethylcholestan-3b-ol (a-epoxysitostanol), (24R)-methylcholestan-3b,5a,6b-triol (campestanetriol) and (24R)-ethylch olest-5-en-3b-ol-7-one(7-ketositosterol). The amounts of these oxyphytosterols in plasma varied from 4·8 to 57·2 ng/ml. There are two possibilities concerning the origin of these compounds. First, they could come from the sma…

Quantitative analysis of fatty acids on choline- and ethanolamine-phospholipids in human ocular and non-ocular tissues by liquid chromatography/tandem mass spectrometry (LC-ESI-MS/MS)

Quantitative analysis of fatty acids on choline- and ethanolamine-phospholipids in human ocular and non-ocular tissues by liquid chromatography/tandem mass spectrometry (LC-ESI-MS/MS). annual meeting of the association-for-research-in-vision-and-ophthalmology (ARVO)