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PubMed1983

Effects of colchicine on the intestinal transport of endogenous lipid. Ultrastructural, biochemical, and radiochemical studies in fasting rats.

The involvement of microtubules in the transepithelial transport of exogenous lipid in intestinal absorptive cells has been suggested. Using electronmicroscopic, biochemical, and radiochemical methods, we have studied the effects of the antimicrotubular agent colchicine on the intestinal mucosa and on the intestinal transport of endogenous lipid of rats in the fasting state. After colchicine treatment, the concentration of triglycerides in intestinal mucosa of rats fasted for 24 h doubled, and electron microscopic studies showed a striking accumulation of lipid particles in absorptive epithelial cells of the tips of jejunal villi. These findings suggest that colchicine interferes with the intestinal transepithelial transport of endogenous lipoproteins. Additional studies, using an intraduodenal pulse injection of [14C]linoleic acid, showed that colchicine does not affect the uptake of fatty acids by intestinal mucosa. However, it had divergent effects on fatty acid esterification, enhancing their incorporation into triglycerides relative to phospholipids, and caused a significant accumulation of endogenous diglycerides, triglycerides, and cholesterol esters within the absorptive intestinal epithelium. Detailed ultrastructural and morphometric studies revealed a decrease of visible microtubules, and a displacement of the smooth and rough endoplasmic reticulum and Golgi apparatus. Furthermore, it is shown that after colchicine treatment, microvilli appear at the lateral plasma membrane of intestinal absorptive cells, a change not previously reported to our knowledge. Thus, our study shows that (a) colchicine causes significant changes in enterocyte ultrastructure and (b) colchicine perturbs the reesterification of absorbed endogenous fatty acids and their secretion in the form of triglyceride-rich lipoproteins from the enterocyte.

Animals↗
PubMedDate not supplied

[Blood lipid changes in rats in hypoxia].

Changes in the total lipid spectrum of serum of rats exposed to acute hypoxia were examined. Quantitative measurements of lipids showed a decrease of total lipids and a redistribution of lipid components in absolute and relative values. A distinct decrease in the quantity of cholesterol ester and a concomitant increase of free cholesterol, an elevation in the relative content of free fatty acids and emergence of diglycerides were noted. The qualitative composition of phospholipids remained unaltered, whereas the absolute amount of glycerophosphates, lysoforms of phosphatids, phosphatid acids and lecithin fraction increased. The changes in the ratio of lipid components are closely connected with the qualitative and quantitative changes in the composition of serum lipoproteins.

Acute Disease↗
PubMed1982

Lipid composition of Microsporum gypseum.

Lipid composition of Microsporum gypseum grown in Sabouraud's liquid media on a rotary shaker were analyzed. The organism contains 6.07% lipid (dry weight basis), of which 75.88% is neutral lipids, 0.9% phospholipids and the rest are glycolipids and pigments. Phospholipids of M. gypseum contain phosphatidyl choline (44.21%), phosphatidyl ethanolamine (17.8%), polyphospho inositide (12.13%), phosphatidyl inositol (8.24%), phosphatidic acid (4.61%) and cardiolipin. Phosphatidyl serine is absent. The neutral lipid composition (expressed as mg/g dry weight of mycelia) of M. gypseum is monoglycerides (1.35), diglyceride (2.87), triglycerides (35.79), free fatty acids (1.00), sterols (3.95) and sterol esters (1.13).

Glycolipids↗
PubMed1982

Studies on the glycolipids of human saliva and gastric juice.

It has been reported that both human saliva and gastric juice (cf. Slomiany, B. L., and Slomiany, A. (1980) in Cell Surface Glycolipids (Sweeley, C. C., ed) American Chemical Society Symposium, No. 128, pp. 149-176, American Chemical Society, Washington, D.C.) contain substantial amounts of certain members of a series of novel glucoglycerolipids with a 1-O-alkyl glyceryl ether backbone. We have analyzed the glycolipids present in samples of saliva obtained from 10 individuals and in samples of gastric juice obtained from 5 individuals. In both fluids, compounds corresponding in the properties studied to standards of glucosyl- and lactosylceramides were found to be the major glycolipids. Other more complex glycosphingolipids were also present in smaller amounts. Human saliva was found to contain two glucoglycerolipids that were not detected in gastric juice. Analyses of these compounds indicated that they were mono- and diglucosyl diglycerides and were probably of bacterial origin. Methanolysis of the glycolipid fractions of saliva and gastric juice failed to reveal the presence of any more than traces of 1-O-alkyl glyceryl ethers. Our results do not exclude the possibility that glyceryl ether-containing glucoglycerolipids occur in human saliva and gastric juice. However, at most they would appear to be rather minor components of either fluid.

Chromatography, Thin Layer↗
PubMedDate not supplied

[Lipid composition of certain predatory species of fungi of the genus Arthrobotrys].

The aim of this work was to study the effect of the composition of the medium on the biosynthetic activity of fungi belonging to the genus Arthrobotrys, the content of different lipid fractions in them, and their fatty acid composition. The following fractions typical of the majority of microbial species were found in the lipid composition of these predaceous fungi: phospholipids, monoglycerides, diglycerides, sterols, free fatty acids, and triglycerides. The fungi were capable of accumulating from 2.4 to 13.2% of lipids in the mycelium. The elevated synthesis of lipids was observed in Arthrobotrys longa 14 and A. musiformis 123 in the modified Meise medium and in wort. The content of lipids in the mycelium was low and the fractions of phospholipids and sterols prevailed upon the growth in chemically defined media. The content of triglycerides was high when the fungi grew in the Meise medium and wort. The fatty acid composition of lipids was identical in all of the studied cultures. The principal saturated fatty acids were myristic, palmitic and stearic. Among unsaturated fatty acids, a high content of oleic and linoleic acids was registered.

Chemical Phenomena↗
PubMedDate not supplied

[Lipids of Raillietina tetragona and Raillietina echinobothrida cestodes from the intestines of hens].

Lipids of the cestodes R. tetragona and R. echinobothrida, parasites of chickens, were studied by thin-layer and gas-liquid chromatography methods. The quantity of neutral lipids amounts to 74.4% in R. tetragona and to 73.1% in R. echinobothrida. Triglycerides amount to 35.6% and 38.4% of the neutral lipids in these species, sterols to 21.6% and 17.2%, sterol esters to 25.1% and 32.0%, diglycerides to 2.8% and 1.4% and free fatty acids to 7.8% and 6.5%, respectively. Fatty acids content of worms is similar but not identical of that of chicken intestine lipids. Cestode infection affects the lipid content of chicken intestine resulting in the decrease of triglycerides and oleic acid quantities and in the increase of the amount of free fatty acids and stearic acid.

Animals↗
PubMedDate not supplied

[Lipids of the luminescent bacteria Photobacterium mandapamensis].

The composition of lipids was studied in the luminescent bacterium Photobacterium mandapamensis under the conditions of maximal luminescence. The synthesis of total lipids and poly-beta-hydroxybutyric acid (PHBA) was investigated in dynamics under the conditions of batch cultivation. The major class of lipids was polar lipids (84.3%) represented by phospholipids (phosphatidyl ethanolamine, phosphatidyl glycerol, cardiolipin, lysocardiolipin, lysophosphatidyl ethanolamine) and a minor nonidentified phospholipid. The fraction of neutral lipids was represented mainly by free fatty acids (about 5%), tri- and diglycerides (in trace amounts), and two nonidentified classes, apparently, hydrocarbons and waxes. A correlation was established between the luminescence of the bacterium and the content of PHBA.

Hydroxybutyrates↗
PubMed1981

The effect of monooctanoin on retained common duct stones.

Monooctanoin is a medium-chain diglyceride that is effective in dissolving cholesterol gallstones in vitro. The in vivo efficacy of monooctanoin was evaluated in eight patients who had monooctanoin infused through the T tube to dissolve retained common duct stones. Five of eight (62%) experienced success. Abdominal cramps and diarrhea were the only side effects, and these resolved by temporarily stopping the infusion or decreasing the rate of the infusion. Since bilirubinate stones accounted for the three failures, the composition of the stone is the determining factor in selecting a treatment plan for retained common duct stones. Retained cholesterol stones can be successfully treated within 4 to 7 days by T-tube infusion of monooctanoin. Pigment stones should be removed by extraction through the T-tube tract or by endoscopic papillotomy.

Adult↗
PubMed1980

Serine esterase inhibitors block stimulus-induced mobilization of arachidonic acid and phosphatidylinositide-specific phospholipase C activity in platelets.

Serine esterase inhibitors (phenylmethanesulfonyl fluoride, 5-dimethylaminonaphthalene-1-sulfonyl (dansyl) fluoride, 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate, or p-nitrophenyl anthranilate) blocked the production of malonyldialdehyde by platelets induced with a variety of stimuli (including thrombin, trypsin, collagen, and A23187). These inhibitors did not block malonyldialdehyde production by platelets from exogenous arachidonic acid. Those inhibitors studied in greater detail (phenylmethanesulfonyl fluoride and 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate) were shown to inhibit the release of [1-14C]arachidonic acid from phosphatidylinositol and phosphatidylcholine in intact platelets but not the conversion of arachidonic acid to thromboxanes, prostaglandins, or hydroxyfatty acids. These inhibitors also blocked the stimulus-induced production of [32P]phosphatidic acid in intact platelets. Both arachidonic acid release from phosphatidylinositol and phosphatidic acid production have been reported to depend on the production of diglyceride by the action on the phosphatidylinositol-specific phospholipase C.f a phosphatidylinositol-specific phospholipase C. That enzyme in the soluble fraction from disrupted platelets was inhibited at concentrations of serine esterase inhibitors which block arachidonic acid release in intact platelets. These results indicate that serine esterase inhibitors block the stimulus-induced mobilization of arachidonic acid in platelets at least in part by their action o

Arachidonic Acids↗
PubMed1980

[On the biosynthesis of glyceride- and phosphoglyceride analogues from monoglyceride analogue 2-(linoleoylamino)-1,3-propanediol in rats (author's transl)].

From L-serine 2-(linoleoylamino)-1,3-propanediol, a monoglyceride analogue, was synthesized and characterized by thin-layer and gas chromatography, infra red spectroscopy and mass spectrometry. After oral application to rats there was an accumulation, almost exclusively in the liver, of triglyceride, diglyceride, phosphatidylcholine and phosphatidylethanolamine analogues with amide-bound linoleic acid. Small amounts of triglyceride analogues could also be detected in the adipose tissue. The analogues were chromatographically isolated using in addition enzymatic and non-enzymatic hydrolysis procedures. Results disclosed that the amide-bound fatty acid of 2-(linoleoylamino)-1,3-propanediol can be absorbed and metabolized intact. Phosphoglyceride analogues are probably formed by the CDP-choline and CDP-ethanolamine pathway fromdiglyceride analogues. Phosphatidylcholine and its analogues disclosed a similar composition of the 1-O-acyl fatty acids. Apparently analogues have in vivo similar substrate properties to hydrolases and acyltransferases as their natural counterparts.

Animals↗
PubMedDate not supplied

[Lipid composition of carboxydobacteria].

The composition of lipids was studied in three strains of carboxydobacteria, viz. Seliberia carboxydohydrogena Z-1062, Pseudomonas gazotropha Z-1156 and Comamonas compransoris Z-1155. The content of lipids extracted with an alcohol--chloroform mixture varied in these strains from 9 to 13.2%. The main classes were phospholipids (from 62.6 to 77.2% of the overall lipid content). The major phospholipids were phosphatidyl ethanolamine and phosphatidyl choline. Moreover, the strains Z-1062 and Z-1156 contained three unidentified phospholipids which constituted 40 and 20% of the total content respectively. The neutral lipids of the carboxydobacteria comprised diglycerides, triglycerides, free fatty acids, methyl esters of fatty acids and a number of compounds which were not identified. The fatty acids of the strains were represented by saturated, monoene and cyclopropanoic acids. The main acids were palmitic, palmitolenic, C17-cyclopropanoic, stearic and octadecenic acids. Polar lipids differed from neutral lipids in their fatty acid composition. The fatty acid composition of firmly bound lipids was characterized by a high degree of saturation, the absence of cyclopropanoic acids and the presence of two unidentified acids that were not found in free lipids; apparently, they belonged to hydroxy acids.

Bacteria↗
PubMedDate not supplied

Lipid composition of strains of the fungus Ustilago zeae (Beckm.) differing as regards their hybridization type.

The composition of the intracellular lipids was studied in four strains of Ustilago zeae differing as regards their hybridization type. In all strains, irrespective of the hybridization type, the bulk of the lipids are formed during the first three days of growth and constitute 43.2--55.7% of the weight of the dry cells. It was established that the total lipid fraction is composed of: phospholipids + monoglycerides, sterols, free fatty acids, diglycerides and sterol esters. The qualitative composition of the total lipids was found to be identical in all four strains regardless of the time of incubation of the cultures. While the qualitative composition remains constant, the ratio of the individual fractions changes in the various strains during the process of incubation. However, compatible strains with respect to hybridization do not differ as regards the amount of individual lipid fractions, while strains incompatible with respect to hybridization differ as regards this trait.

Basidiomycota↗
PubMed1993

Chemoattraction of neutrophils by substance P and transforming growth factor-beta 1 is inadequately explained by current models of lipid remodeling.

"Classical" chemoattractants, such as FMLP, C5a, or leukotriene B4, not only elicit directed motility but also activate neutrophils (degranulation, release of active oxygen species). Signal transduction after ligation of receptors for these classical chemoattractants is mediated by pertussis toxin (PT)-sensitive, heterotrimeric G proteins and the early production of lipid messengers via phospholipases. In contrast, we have previously shown that substance P (SP) and transforming growth factor-beta 1 (TGF-beta 1) are "pure" chemoattractants in that they elicit chemotaxis without activating neutrophils. Paradoxically, pure chemoattractants also activate G proteins (plasmalemmal GTPase activity) without eliciting increments in cytosolic calcium ([Ca]i) and thus inositol trisphosphate. We therefore determined lipid remodeling and signal transduction in response to pure chemoattractants. Increments in plasmalemmal GTPase activated by SP (0.1 microM) and TGF-beta 1 (40 fM), like that after FMLP, were PT-sensitive (SP = 6.6 +/- 2 pm/mg/min vs SP + PT = 1.1 +/- 0.9 over basal activity; TGF-beta 1 = 4.3 +/- 1.6 vs TGF-beta 1 + PT = 2.3 +/- 0.9). In parallel, treatment of PMN with PT (1 microgram/ml, 30 min) inhibited chemotaxis (under agarose) after FMLP (2175 +/- 176 (SEM) microns vs 726 +/- 267) and SP (411 +/- 99 microns vs 103 +/- 62 microns) and TGF-beta 1 (40 fM, 375 +/- 53 microns vs 83 +/- 47). However, G proteins coupled to receptors for SP and TGF-beta 1, unlike FMLP, did not appear to be linked to phospholipases in that neither increments in diacylglycerol were detected after receptor ligation (FMLP = 152 +/- 22% resting levels; SP = 101 +/- 5%; TGF-beta 1 = 105 +/- 4%) nor was alkylacylglycerol increased by exposure to SP or TGF-beta 1 (SP = 92 +/- 4%; TGF-beta 1 = 101 +/- 8%; FMLP = 226 +/- 40%). Moreover, polymorphonuclear leukocytes failed to generate phosphatidates (PA) of either species after SP (DA-PA = 79 +/- 9% resting at 60 s; EA-PA = 103 +/- 4%) or TGF-beta 1 (DA-PA = 101 +/- 5%; EA-PA = 98 +/- 9%) in contrast to FMLP (DA-PA = 155 +/- 22%; EA-PA = 149 +/- 16%). The data clearly contravene the current dogma that all chemoattractants use inositol trisphosphate and diglycerides as intracellular signals and suggest the presence of a unique subset of PT-sensitive G proteins, not coupled to "classical" phospholipases, transduce chemoattraction.

Adult↗
PubMed1995

Structural and stereochemical studies of potent inhibitors of glucosylceramide synthase and tumor cell growth.

Analogs and homologs of PDMP were synthesized, based on its structure (D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol). This compound had previously been found to block the synthesis of GlcCer (glucosylceramide). Increasing the acyl chain length from 10 to 16 carbon atoms greatly enhanced the efficacy of the enzyme inhibitor, as did the use of a less polar cyclic amine, especially a pyrrolidine instead of a morpholine ring. Replacement of the phenyl ring by a chain corresponding to sphingosine also yielded a strongly inhibitory material. By using a chiral synthetic route, we showed that the isomers active against GlcCer synthase had the R,R-(D-threo)-configuration. However, strong inhibition of the growth of human cancer cells in plastico was produced by both the threo and erythro racemic compounds, showing involvement of an additional factor (beyond simple depletion of cell glycosphingolipids by blockage of GlcCer synthesis). The growth arresting effects could be correlated with increases in cellular ceramide and diglyceride levels. The aliphatic pyrrolidino compound was strongly inhibitory toward the glucosyltransferase and produced almost complete depletion of glycolipids, but did not inhibit growth or cause an accumulation of ceramide. Attempts were made to see whether the differences in growth effects could be attributed to the influence of the inhibitors on related enzymes (ceramide and sphingomyelin synthase and ceramidase and sphingomyelinase). While some stimulation of enzyme activity was noted, particularly at high inhibitor concentrations (50 microM), these findings did not explain the differing effects of the different inhibitors. The best inhibitors of GlcCer synthase compared favorably in efficacy with some cancer chemotherapeutic drugs in current use when tested with a battery of human cancer cells.

Animals↗
PubMedDate not supplied

[The effect of lipid peroxidation on the lipid and phospholipid composition of mitochondrial membranes during thermal incubation].

Alterations in the content of lipids and phospholipids were studied in rat liver mitochondrial membranes after long-term heating at 37 degrees, pH 7.4, using FeSO4-ascorbate as inductors of lipid peroxidation. Under these conditions, activation of lipid peroxidation in mitochondrial membranes led to a marked increase in the rate of hydrolysis of phosphatidylethanolamine and lysophosphatidylethanolamine, to elevated synthesis of phosphatidylserine, sphingomyelin, phosphatidic and lysophosphatidic acids, diglycerides and cholesterol esters as well as to inhibit hydrolysis of phosphatidylcholine, cardiolipin and their lyso-derivatives.

Animals↗
PubMed1994

Clinical evaluation of a new rapid assay for serum lipase determination.

We evaluated a new continuous colorimetric method for serum lipase determination based on the use of a 1,2-diglyceride as substrate and a specific 2-monoglyceride lipase. This test was compared with a turbidimetric assay and also with serum alpha-amylase and pancreatic isoamylase determinations. We studied 32 patients with acute pancreatitis, 27 with chronic pancreatitis in acute painful relapse, 19 with pancreatic cancer, 44 with other digestive diseases, 53 with end-stage renal disease, and 102 healthy controls. The results of the new test were closely correlated with those of the turbidimetric method (r = 0.96). Sensitivity of the new method was elevated (100%): it was the same as that of the turbidimetric method, but slightly higher than that of alpha-amylase and pancreatic isoamylase determinations (93.7 and 96.9%, respectively). Specificity was 95.5%, i.e. higher than that observed using the other tests (86.4, 84.1 and 88.6% for lipase turbidimetric assay, amylase, and pancreatic isoamylase determinations, respectively). The results demonstrate that this new lipase assay is a sensitive, specific test for the diagnosis of acute pancreatitis.

Acute Disease↗
PubMed1994

[The effect of polyene phosphatidylcholine (Essentiale forte) in the treatment of liver steatosis and ultrasound findings--preliminary study].

BACKGROUND: Steatosis of the liver is the most frequent diffuse liver disease and its detection increased markedly due to ultrasonography. The presence of lipid particles in hepatocytes alters the ultrastructure of cellular membranes. The damaged cell is unable to meet adequately the energy requirements of phospholipid synthesis, the latter being the basic component of cellular and subcellular membranes. Substitution of "essential" phospholipids plays an important role in their regeneration. OBJECTIVE: The objective of the open trial without controls was to obtain preliminary information on the effectiveness of Essentiale forte cps. in the treatment of steatosis of the liver of varying etiology in a group of 30 women, focused on changes in the ultrasonic pictures and a parallel follow-up of laboratory findings and subjective feelings, to be followed subsequently by a placebo controlled double blind trial. METHODS AND RESULTS: Ultrasonic examinations were made using a Hewlett-Packard apparatus (77065AR). The sonographic criterium of steatosis was the finding of a diffusely enhanced echogenicity of the liver parenchyma associated as a rule with varying degrees of hepatomegaly with a smooth rounded margin and readily apparent hepatic veins with a normal lumen. The preparation Essentiale forte, cps. Rhône-Poulenc Rorer Co., contains natural "essential" phospholipids, diglyceride esters of cholinephosphoric acid (enriched with unsaturated fatty acids (linolic, linoleic, oleic) 300 mg, vitamin B1 6 mg, vitamin B2 6 mg, vitamin B6 6 mg, vitamin B12 6 micrograms, nicotinamide 30 mg, vitamin E 6 mg. Six tablets per day (2 x 3 tablets) were administered for six months. The clinical, ultrasonic and laboratory examination were made at the onset of the trial and then after the second and sixth month. From the total number of 28 women who completed treatment in 29 % (8 woman) were free from sonographic signs of steatosis and only in 25 % (7 women) the finding remained unaltered. In the remainder the ultrasonic picture improved only partly, in 10 of 11 women (91 %) the non-homogeneity of the parenchyma disappeared, in 3 of 12 women (25 %) the conduction of acoustic signals improved. The authors recorded also regression of hepatomegaly from 12.9 +/- 1.5 cm to 11.4 +/- 1.0 cm (p < 0.0001). There was also a significant decline of laboratory values: ALT from 1.650 +/- 1.612 mu kat/l to 0.812 +/- 0.392 mu kat/l (p < 0.0014), AST from 1.308 +/- 1.341 mu kat/l to 0.613 +/- 0.206 mu kat/l (p < 0.0038), GMT from 2.525 +/- 3.374 mu kat/l to 0.976 +/- 0.727 mu kat/l (p < 0.0078). A statistically significant decline was also found in mean values of total bilirubin (p < 0.0316), cholesterol (p < 0.0129) and triglycerides (p < 0.001). In all patients subjective sensations improved (p < 0.05). CONCLUSIONS: The authors provided evidence than in 53.6 % of patients the effect of six-month treatment with Essentiale forte was very good (improvement of all investigated parameters), partial in 42.9 % (improvement of laboratory findings and subjective complaints) ad not quite satisfactory in 3.6 % (only improvement of subjective feelings).

Adolescent↗
PubMed1994

Calorimetric studies and molecular mechanics simulations of monounsaturated phosphatidylethanolamine bilayers.

This investigation was designed to determine how information about the lipid chain melting and structural characteristics of sn-1 saturated/sn-2 monounsaturated phosphatidylethanolamines, a subclass of naturally occurring phospholipids, can be generalized among these lipid molecules. Specifically, 30 molecular species of sn-1 saturated/sn-2 unsaturated monoenoic phosphatidylethanolamines were semi-synthesized. The phase transition behavior of these monoenoic lipids in excess water was studied calorimetrically. The computer-based molecular mechanics approach was used to simulate the energy-minimized structures and to calculate steric energies for the diglyceride moieties of some of the 30 monoenoic lipid molecules, at T < Tm, in various aggregated states. These combined calorimetric and computational studies led to the following results and conclusions. 1) For a homologous series of monoenoic lipids with a common molecular weight and with a cis-double bond at various positions along the sn-2 acyl chain, the characteristic reduction of the main phase transition temperature (Tm) is proposed to be a result of an entropy-driven phenomenon. 2) The maximal decrease in the Tm for bilayers prepared from four series of monoenoic phosphatidylethanolamines containing a sn-2 octadecenoyl chain is shown by interpolation of calorimetric data to occur uniquely when the cis double bond is located commonly between C(10) and C(11) positions from the carboxyl end. 3) Monoenoic phosphatidylethanolamines can be divided into two groups. The Tm values obtained with bilayers of monoenoic lipids within each group can be systematically correlated with their structural parameters, leading to the derivation of two general Tm-structure relationships.

Calorimetry, Differential Scanning↗