Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PLASMALOGEN”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,549 records · Page 86Linked to original sources

Lipid chemistry.

Explore the source record for details and available documents.

Alcohols↗

Are biochemical parameters of lung maturation from gastric, tracheal, and pharyngeal aspirates comparable?

Phospholipid parameters -- lecithin/sphingomyelin (L/S) ratio and palmitic acid/stearic acid (P/S) ratio -- of gastric (GA), pharyngeal (PA), and tracheal aspirates (TA) have often been used for estimation of lung maturation. However, it was not known whether values from different sources can be alternatively used. The study was performed to test whether P/S and L/S ratios in GA, PA, and TA are comparable. 11 GA, 30 PA, and 10 TA were obtained from infants within 10 min after birth. All infants were healthy, vaginally delivered with no respiratory distress, and had a gestational age > or = 34 weeks. Patterns of fatty acids were determined by gas chromatography and the L/S ratio by high-performance liquid chromatography. We found lower L/S ratios in GA (16.5 +/- 5.2) when compared with PA(39 +/- 16) or TA (41 +/- 15; p < 0.01); there were no differences between PA and TA. The P/S ratio was in the same range in PA and TA, but lower in GA. As compared with TA and PA, in GA the relative percentage of palmitic acid of all fatty acids was lower, the percentage of monounsaturated fatty acids, however, higher. We conclude that phospholipid parameters of lung maturation in PA and TA, but not in GA, can be alternatively used.

Gastric Juice↗

Time course of changes in porcine myocardial phospholipid levels during ischemia. A reassessment of the lysolipid hypothesis.

This study was performed to determine the early and delayed metabolic effects of myocardial ischemia on the major membrane phospholipids and to reassess the potential role of lysophospholipids in the genesis of malignant dysrhythmias induced by ischemia. Samples taken from in situ hearts before ant at various intervals up to 40 minutes after abrupt ligation of LAD were extracted by the classical Folch technique with modifications to avoid artifactual lysophospholipid production and losses. Following thin layer chromatography of lipid extracts, phospholipid fractions were quantified by phosphorus estimation and lysophospholipids by a more sensitive method employing gas liquid chromatography. The total phospholipid content with the exception of lysophospholipids remained essentially constant throughout the early phases of acute ischemia, but fell by 6 and 14% after 8 and 24 ours, respectively. At 8 minutes, lysophospholipid levels n ischemic myocardium were significantly increased by 60% compared to pre-occlusion controls in the ischemic zone and by 25% in post-occlusion controls. They changed little thereafter. The molecular species of lysophospholipids remained unchanged throughout the period of ischemia studied. The mole fraction of other phospholipids as well as their fatty acyl and aldehyde profiles also were unchanged. Despite significant elevations in lysophospholipids levels, their absolute quantities were very small (0.6% of total phospholipid P) and 15-fold smaller than that reported in vitro to simulate electrophysiological manifestation of ischemia. However, such small amounts in vivo, if produced in the microenvironment of certain membrane-bound enzymes along with acidosis, hypoxia, and fatty acids, could be potentially deleterious to cell functions.

Animals↗

Biochemical and morphological changes in endothelial cells in response to hypoxic interstitial edema.

BACKGROUND: A correlation between interstial pulmonary matrix disorganization and lung cellular response was recently documented in cardiogenic interstitial edema as changes in the signal-cellular transduction platforms (lipid microdomains: caveoale and lipid rafts). These findings led to hypothesize a specific "sensing" function by lung cells resulting from a perturbation in cell-matrix interaction. We reason that the cell-matrix interaction may differ between the cardiogenic and the hypoxic type of lung edema due to the observed difference in the sequential degradation of matrix proteoglycans (PGs) family. In cardiogenic edema a major fragmentation of high molecular weight PGs of the interfibrillar matrix was found, while in hypoxia the fragmentation process mostly involved the PGs of the basement membrane controlling microvascular permeability. Based on these considerations, we aim to describe potential differences in the lung cellular response to the two types of edema. METHODS: We analysed the composition of plasma membrane and of lipid microdomains in lung tissue samples from anesthetized rabbits exposed to mild hypoxia (12 % O2 for 3-5 h) causing interstitial lung edema. Lipid analysis was performed by chromatographic techniques, while protein analysis by electrophoresis and Western blotting. Lipid peroxidation was assessed on total plasma membranes by a colorimetric assay (Bioxytech LPO-586, OxisResearch). Plasma membrane fluidity was also assessed by fluorescence. Lipid microdomains were isolated by discontinuous sucrose gradient. We also performed a morphometric analysis on lung cell shape on TEM images from lung tissue specimen. RESULTS: After hypoxia, phospholipids content in plasma membranes remained unchanged while the cholesterol/phospholipids ratio increased significantly by about 9% causing a decrease in membrane fluidity. No significant increase in lipid peroxidation was detected. Analysis of lipid microdomains showed a decrease of caveolin-1 and AQP1 (markers of caveolae), and an increase in CD55 (marker of lipid rafts). Morphometry showed a significant decrease in endothelial cell volume, a marked increase in the cell surface/volume ratio and a decrease in caveolar density; epithelial cells did not show morphological changes. CONCLUSION: The biochemical, signaling and morphological changes observed in lung endothelial cell exposed to hypoxia are opposite to those previously described in cardiogenic edema, suggesting a differential cellular response to either type of edema.

Animals↗

Separate myocardial ethanolamine phosphotransferase activities responsible for plasmenylethanolamine and phosphatidylethanolamine synthesis.

Ethanolamine phosphotransferase (EPT) is a key enzyme responsible for the synthesis of ethanolamine glycerophospholipids. Plasmenylethanolamine is a predominant molecular subclass of ethanolamine glycerophospholipids in the heart. The present study was designed to identify the selective use of 1-O-alk-1'-enyl-2-acyl-sn-glycerol as a substrate for EPT as a mechanism responsible for the predominance of plasmenylethanolamine in the rabbit heart. EPT activity in rabbit myocardial membranes using 1,2-diacyl-sn-glycerol as substrate is activated by Mn2+, inhibited by dithiobisnitrobenzoic acid (DTNB) and is unaffected by Ca2+. In contrast, ethanolamine phosphotransferase activity using 1-O-alk-1'-enyl-2-acyl-sn-glycerol as substrate is inhibited by Mn2+ and Ca2+, but is activated by DTNB. Additionally, ethanolamine phosphotransferase activity using 1-O-alk-1'-enyl-2-acyl-sn-glycerol substrate was more sensitive to thermal denaturation compared with that of 1,2-diacyl-sn-glycerol. Taken together, these results suggest that separate ethanolamine phosphotransferase activities are present in heart membranes that are responsible for the synthesis of phosphatidylethanolamine and plasmenylethanolamine.

Animals↗

Analysis of peroxisomes in lymphoblasts: Zellweger syndrome and a patient with a deletion in chromosome 7.

Lymphoblasts are useful cells for the diagnosis and basic studies of several human genetic disorders. Peroxisomal disorders are usually diagnosed by using fibroblasts or blood samples. Here, we report the characterization of peroxisomes in lymphoblasts. We demonstrated that lymphoblasts from a patient with Zellweger syndrome, the prototypical disorder of peroxisome biogenesis, contained peroxisomal ghosts like those described previously in Zellweger fibroblasts. We also found that lymphoblasts that carry a deletion on chromosome 7 (q11.23q22.1), a region thought to contain one Zellweger syndrome gene, contained normal peroxisomes.

Cell Line↗

Severe deficiency of docosahexaenoic acid in peroxisomal disorders: a defect of delta 4 desaturation?

In confirmation of previous findings, patients with Zellweger's syndrome had extremely low levels of docosahexaenoic acid (22:6 omega 3) in the brain, liver, and kidneys. The other product of delta 4 desaturation, 22:5 omega 6, was also very significantly decreased, as were the ratios 22:6 omega 3/22:5 omega 3 and 22:5 omega 6/22:4 omega 6, especially in the brain and liver of the Zellweger patients. The infant with pseudo-Zellweger's syndrome also had very low levels of 22:6 omega 3 and of the ratio 22:6 omega 3/22:5 omega 3 in all tissues, especially in the brain, where the index 22:5 omega 6/22:4 omega 6 was also very significantly reduced. The ratio 22:6 omega 3/22:4 omega 6 was markedly decreased in all tissues, in Zellweger's as well as in pseudo-Zellweger's syndrome. The findings reported here strongly reinforce the hypothesis of a new enzymatic defect in peroxisomal disorders involving the desaturation of long polyunsaturated fatty acids, especially of the omega 3 family.

Aldehydes↗