Chloroquine-induced phospholipid fatty liver. Measurement of drug and lipid concentrations in rat liver lysosomes

A method has been developed to measure the concentration of chloroquine in lysosomes isolated from the liver of rats. It employs 3H2O and [U-14C]sucrose to determine the intralysosomal water volume of purified lysosomes obtained by free flow electrophoresis. Twelve h after a single dose, the concentration of chloroquine in lysosomes was 6.3 mM and at 24 h it rose to 16.5 mM. With continued treatment, lysosomal chloroquine concentrations were 61 and 74 mM at 48 and 72 h. The lysosomal concentrations of chloroquine attained were sufficient to block intralysosomal phospholipase A1 activity. The lysosomal content of phospholipid rises 1.7-fold and 2.6-fold over that of control at 12 and 24 h, respectively. At 72 h, lysosomal phospholipid was 3.7-fold greater than that of control. Lysosomes show an increased negative surface charge with chloroquine administration which is due in part to an increased ratio of acidic to neutral phospholipids in the lysosomal membrane. The phosphatidylinositol content of lysosomes rose rapidly with chloroquine treatment and accounted for the early increase in the ratio. Bis(monoacylglycero)phosphate, an acidic phospholipid synthesized only in lysosomes, increased later in the course of chloroquine treatment and accounted for the continued increase in acidic phospholipids.     

The isolation of lysosomes from normal rat liver by affinity chromatography

Lysosomes from normal rat liver were isolated by affinity chromatography using Sepharose-bound Ricinus communis agglutinins I + II. Characterization of the lysosomal fraction by marker enzymes showed--compared with the homogenate--an enrichment in: acid phosphatase and arylsulfatase about 30- to 60-fold, the tartrate-sensitive acid phosphatase about 95-fold, whereas beta-D-glucosidase, beta-D-galactosidase and sphingomyelinase showed a much higher enrichment of 170- to 260-fold. Marker enzymes for other cell organelles were not detectable. The phospholipid pattern and optical control with electron microscopy gave further indications that the isolated fractions were very rich in lysosomes. A comparison of the phospholipid compositions of plasma membranes isolated from normal rat liver and membranes from the isolated fractions of lysosomes, showed that they were quite different; in particular bis(monoacylglycero)phosphate, which we found to be a typical lysosomal phospholipid, was absent in plasma membranes.     

Effect of the segregation and accumulation of chloroquine and daunorubicin by L cells (LSM subline) on the activity of lysosomal hydrolases

Kinetics of chloroquine and daunorubicin (DNR) uptake by cultured L cells (subline LSM) has been studied. With their constant concentrations in the medium the uptake of both chloroquine and DNR was characterized as a two phase process. Within 1.5-2 hours, these cells accumulated as much as 90 per cent of the total chloroquine and DNR amounts taken up during the whole incubation period. The segregation and accumulation of these substances took place in lysosomes. Chloroquine and DNR concentrations within lysosomes exceed those in the medium by 1100 and 5000 times, respectively. The chloroquine and DNR accumulation in lysosomes inhibited activities of some lysosomal hydrolases tested: cathepsins B and D, N-acetyl-beta, D-glucosaminidase and acid phosphatase. Unlike, the activity of acid lipase was not affected by chloroquine, and was sufficiently stimulated (by 55%) by DNR. The mechanism of inhibition of lysosomal enzymes by chloroquine and DNR is not yet known, although some suggestions are made. Possible consequences of lysosomal activity inhibition for cell metabolism are discussed in addition to a possible role of lysosomotropic agents as regulators of lysosomal functional activity.     

Effect of chloroquine on the stability of rat kidney lysosomes in vivo and in vitro

1. Chronic administration of chloroquine to rats results in increased urinary excretion of lysosomal acid phosphatase, muramidase and cathepsin D. 2. Various concentrations of chloroquine caused lysosomal membrane swelling as shown by decrease of light absorbance in lysosomal suspensions. 3. Incubating lysosomal suspensions in the presence of chloroquine resulted in a marked lysosomal acid phosphatase release. 4. Addition of acetylsalicylic acid, a lysosomal membrane stabilizer, into a lysosomal suspension containing chloroquine, reduced the degree of lysosomal membrane swelling and acid phosphatase release. 5. The results suggest a labilizing effect of chloroquine on rat kidney lysosomes.     

Characterization of nuclear membranes and endoplasmic reticulum isolated from plant tissue

Nuclei, nuclear membranes and rough endoplasmic reticulum (rER) were isolated from onion root tips and stems. Structural preservation and purity of the fractions was determined by electron microscopic and biochemical methods. Gross compositional data (protein, phospholipid, nonpolar lipids, sterols, RNA, DNA), phospholipid and fatty acid patterns, enzyme activities (ATPases, ADPase, IDPase, glucose-6-phosphatase, 5'-nucleotidase, acid phosphatase, and NADH- and NADPH-cytochrome C reductases), and cytochrome contents were determined. A stable, high salt-resistant attachment of some DNA with the nuclear membrane was observed as well as the association of some RNA with high salt-treated nuclear and rER membranes. The phospholipid pattern was identical for both nuclear and rER membranes and showed a predominance of lecithin (about 60%) and phosphatidyl ethanolamine (20-24%). Special care was necessary to minimize lipid degradation by phospholipases during isolations. Nonpolar lipids, mostly sterols and triglycerides, accounted for 35-45% of the membrane lipids. Sterol contents were relatively high in both membrane fractions (molar ratios of sterols to phospholipids ranged from 0.12 to 0.43). Sitosterol accounted for about 80% of the total sterols. Palmitic, oleic, and linoleic acids were the most prevalent acids in membrane-bound lipids as well as in storage lipids and occurred in similar proportions in phospholipids, triglycerides and free fatty acids of the membrane. About 80% of the fatty acids in membrane phospholipids and triglycerides were unsaturated. A cytochrome of the b5 type was characterized in these membranes, but P-450-like cytochromes could not be detected. Both NADH and NADPH-cytochrome c reductases were found in nuclear and rER membranes and appeared to be enriched in rER membranes. Among the phosphatases, Mg2+-ATPase and, to lesser extents, ADPase, IDPase and acid phosphatase activities occurred in the fractions, but significant amounts of monovalent ion-stimulated ATPase, 5'-nucleotidase and glucose-6-phosphatase activities did not. The results obtained emphasize that the close biochemical similarities noted between rER and nuclear membranes of animal cells extend to these fractions from plant cells.     

Fatty chain composition of phospholipids in sea urchin spermatozoa

1. An analysis was made of lipids extracted from the spermatozoa of the sea urchins, Hemicentrotus pulcherrimus and Anthocidaris crassispina. 2. Nearly all the lipids from both species consisted of phospholipids (about 80%) and cholesterol (about 14%). Triglyceride and cholesterol ester were present in trace amounts. 3. The fatty acid composition of each phospholipid was determined by gas-liquid chromatography. In both species, the fatty acid consisting of phosphatidylethanolamine was of the unsaturated type for the most part, while cardiolipin was comprised to a considerable degree of saturated fatty acids. In phosphatidylcholine and phosphatidylserine from H. pulcherrimus sperm, unsaturated fatty acid content was somewhat higher than that in phospholipids from A. crassispina sperm.     

Amphiphilic cationic drugs and phospholipids influence the activities of beta-galactosidase and beta-glucosidase from liver lysosomal fraction of untreated rats

The influence of amphiphilic drugs and phospholipids on the activities of beta-galactosidase and beta-glucosidase from liver lysosomal fractions of untreated rats, isolated by affinity chromatography using castor bean lectins, was studied in vitro. Chloroquine (93 microM) inhibited beta-galactosidase activity by about 30%, while O,O'-bis(diethylaminoethyl)hexestrol showed no inhibitory effect. Neutral phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelin) inhibited the enzyme slightly, while the enzyme activity was drastically reduced in the presence of acidic phospholipids (phosphatidylinositol, phosphatidylserine, bis-(monoacylglycero)phosphate). Lysosomal beta-glucosidase was strongly inhibited by chloroquine and O,O'-bis(diethylaminoethyl)-hexestrol. The neutral phospholipids showed only a moderate inhibitory effect, whereas the acidic phospholipids were stimulators. Bis(monoacylglycero)phosphate was by far the best stimulating compound.     

Subcellular fractionation of epiphyseal cartillage isolation of matrix vesicles and profiles of enzymes,phospholipids, calcium and phosphate

Epiphyseal cartilage was fractionated into subcellular components by non-enzymatic methods, and analyzed for activity of marker enzymes, for phospholipids, and for calcium and inorganic phosphate. Alkaline phosphatase, a marker enzyme for matrix vesicles and plasma membranes, was concentrated in the 100 000 × g (microsomal) pellet and, upon subsequent frationalism, in the low-density fractions from the sucrose gradient. Mitochondrial and endoplasmic reticular enzymes were localized primarily in the 20 000 × g pellet, lysosomal enzymes predominantly in the supernate from the microsomal pellet. Two phospholipids characteristic of matrix vesicles, sphingomyelin and phosphatidylserine, were enriched in the low-density sucrose fractions; however, unlike matrix vesicles, there was no depletion in phosphatidylcholine or increase in lysophospholipids. Ca and inorganic P were concentrated in the higher-density fractions, the amounts in the lower-density fractions being some- what lower than those seen in matrix vesicles. The alkaline phosphatase-rich, low-density fractions were thus not identical to matrix vesicles isolated by collagenase digestion, but rather appear to be composed primarily of plasma membranes. Enzyme profiles indicate they were relatively free of mitochondrial, endoplasmic reticular and lysosomal contaminants. The data further indicate that significant modification of the phospholipid, electrolyte, and possibly enzyme content of chondrocyte plasma membranes, must occur during blebbing and matrix vesicle formation.     

Involvement of phospholipids in polyunsaturated Fatty Acid synthesis in developing soybean cotyledons

Developing soybean (cv. Dare) cotyledons harvested at 30 days after flowering were pulse-labeled with [1-(14)C]oleoyl-CoA. The metabolic interrelation of radiolabeled unsaturated fatty acids between the major glycerolipid classes was determined at various time intervals. At chase time zero, [(14)C]oleic acid accounted for 99.2% of the total glycerolipid radioactivity, and phospholipids contained 92% of the total incorporated radioactivity. With time, phospholipids were metabolized in triacylglycerol biosynthesis and radioactivity was detected in polyunsaturated fatty acids. The hypothesis that phospholipids were metabolic intermediates in polyunsaturated fatty acid biosynthesis was tested by comparing the theoretical and the actual amount of radiolabeled oleic acid that was associated with triacylglycerol as a function of time. The radioactive oleic acid found in triacylglycerol at various intervals was derived from phospholipids via a diacylglycerol intermediate. Assuming no phospholipid desaturation, the potential or theoretical amounts of [(14)C]oleic acid that could be transferred to triacylglycerol from phospholipids was defined by a system of differential equations. The results demonstrated that the decline in [(14)C]oleic acid from phospholipid after long chase intervals was equal to the total amount of radioactive unsaturated fatty acids found in neutral lipids. The difference between the theoretical and actual amounts of [(14)C]oleic acid present in triacylglycerol after long time intervals was equal to the amount of radioactivity present in polyunsaturated fatty acids. Based upon those findings in soybeans, the desaturation of oleic acid associated with phospholipids was highly probable.     

Fatty acid synthesis in Escherichia coli is indirectly inhibited by phenethyl alcohol.

Experiments were performed to determine how phenethyl alcohol inhibits phospholipid synthesis in E. coli. At a nonbacteriostatic concentration, the drug reduces the rate of de novo fatty acid and phospholipid synthesis by 60 to 70%. The inhibition of fatty acid synthesis was found to be a secondary consequence of the inhibition of phospholipid synthesis. Phenethyl alcohol reduces the rate of incorporation of exogenous fatty acids into the phospholipids of a fatty acid auxotroph by 60%. These results indicate that this drug controls phospholipid synthesis beyond the level of fatty acid synthesis. Phenethyl alcohol inhibits the synthesis of phospholipids containing saturated fatty acids to a greater extent than it does the synthesis of phospholipids containing unsaturated fatty acids. It controls the synthesis of phospholipids containing saturated fatty acids at both the level of fatty acid synthesis and the level of incorporation of the saturated fatty acids into phospholipids. The synthesis of phospholipids containing unsaturated fatty acids is inhibited at the level of incorporation of the fatty acids into phospholipids.     

Sterol carrier protein-2 expression alters plasma membrane lipid distribution and cholesterol dynamics

Although sterol carrier protein-2 (SCP-2) binds, transfers, and/or enhances the metabolism of many membrane lipid species (fatty acids, cholesterol, phospholipids), it is not known if SCP-2 expression actually alters the membrane distribution of lipids in living cells or tissues. As shown herein for the first time, expression of SCP-2 in transfected L-cell fibroblasts reduced the plasma membrane levels of lipid species known to traffic through the HDL-receptor-mediated efflux pathway: cholesterol, cholesteryl esters, and phospholipids. While the ratio of cholesterol/phospholipid in plasma membranes of intact cells was not changed by SCP-2 expression, phosphatidylinositol, a molecule important to intracellular signaling and vesicular trafficking, and anionic phospholipids were selectively retained. Only modest alterations in plasma membrane phospholipid percent fatty acid composition but no overall change in the proportion of saturated, unsaturated, monounsaturated, or polyunsaturated fatty acids were observed. The reduced plasma membrane content of cholesterol was not due to SCP-2 inhibition of sterol transfer from the lysosomes to the plasma membranes. SCP-2 dramatically enhanced sterol transfer from isolated lysosomal membranes to plasma membranes by eliciting detectable sterol transfer within 30 s, decreasing the t(1/2) for sterol transfer 364-fold from >4 days to 7-15 min, and inducing formation of rapidly transferable sterol domains. In summary, data obtained with intact transfected cells and in vitro sterol transfer assays showed that SCP-2 expression (i) selectively modulated plasma membrane lipid composition and (ii) decreased the plasma membrane content cholesterol, an effect potentially due to more rapid SCP-2-mediated cholesterol transfer from versus to the plasma membrane.     

Insulin effect on some biochemical and biophysical characteristics of lung surfactant

The incorporation of [14C]palmitic acid into rat alveolar wash total phospholipids and phospholipid fractions has been followed for 6, 8, 10 and 12 hr after insulin administration, indicating a considerable enhancement. The fatty acid profiles of phosphatidylcholines, phosphatidylethanolamines and phosphatidylglycerols were found changed after the hormone administration. Eight hours post insulin treatment the precursor incorporation was highest in all phospholipid fractions studied, as well as the contribution of long chain fatty acids. Dynamic monolayer studies of the lung wash lipid extracts indicated a maximally expanded lipid film corresponding to the highly unsaturated phospholipids present.     

Fatty acids of rice coleoptiles in air and anoxia

The metabolism of lipids, like that of other components, was adversely and strongly affected when rice (Oryza sativa L.) coleoptiles were grown anaerobically. In aerobic coleoptiles, the amounts of total fatty acid, phospholipid, and total lipid per coleoptile increased by 2.5- to 3-fold between days three and seven, whereas under anoxia, the increases were all less than 60%. The total amount of lipid at day seven in anoxia was less than 30% of that in air. In air, the total fatty acid content at day three was 25 nanomoles per coleoptile and this increased to over 71 nanomoles per coleoptile at day seven. All acids except 18:0 showed substantial increases. In anoxia, the corresponding values for total fatty acids were 24 nanomoles and 27 nanomoles. The small increases were confined to the saturated fatty acids; no significant increase occurred in unsaturated fatty acids. A minor fatty acid constituent (16:1) increased from 0.09 to 1.99 nanomoles per coleoptile between days three and seven in air. This component was never observed in any fatty acid preparation from anaerobic coleoptiles. The major phospholipids under all conditions were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid. A small amount of unidentified phosphoester, not present on thin layer chromatography plates from aerobic coleoptiles, was seen in extracts of anaerobic coleoptiles. The fatty acyl substituents of each of the phospholipids were analyzed at days three and seven in coleoptiles grown aerobically and in anoxia. Each phospholipid had its own distinctive fatty acid composition which remained fairly constant under all treatments; 16:0 and 18:2 were the most abundant fatty acids in every phospholipid class. In air, the percentages of total fatty acids that were in the phospholipids were 86% on day three and 87% on day seven. In anoxia, the values at the corresponding ages were 47 and 57%. Since no net synthesis of unsaturated fatty acids occurred in anaerobic conditions, the small increase in total unsaturated acids in the phospholipids between days three and seven must have occurred at the expense of fatty acids preexisting in the neutral lipid. No unusual pathways of biosynthesis or unusual precursors are required to explain the presence of unsaturated fatty acids in the rice coleoptile. The present study and results of experiments where coleoptiles were fed [¹⁴C]acetate (BB Vartapetian et al. 1978 Plant Sci Lett 13:321-328) clearly show that unsaturated fatty acid synthesis in rice coleoptiles requires O₂, as it does in other plants.     

Mechanism of ethanol-induced changes in lipid composition of Escherichia coli: inhibition of saturated fatty acid synthesis in vivo.

The in vivo effects of ethanol on lipid synthesis in Escherichia coli have been examined. Under conditions which uncoupled fatty acid synthesis from phospholipid synthesis, ethanol decreased the amount of saturated fatty acids synthesized but had little effect on the selectivity of their incorporation into phospholipids. In the absence of fatty acid degradation and unsaturated fatty acid synthesis, E. coli was still able to adapt its membrane lipids to ethanol, while the inhibition of total fatty acid synthesis eliminated this response. During growth in the presence of ethanol, strain K1060 (an unsaturated fatty acid auxotroph) incorporated an increased amount of exogenous heptadecanoic acid (17:0) to compensate for the reduction in palmitic acid (16:0) available from biosynthesis. Thus, our results indicate that the reduced levels of saturated fatty acids observed in the phospholipids of E. coli following growth in the presence of ethanol result primarily from a decrease in the amounts of saturated fatty acids available for phospholipid synthesis.     

Influence of chloroquine treatment on enzymes and phospholipids from rat liver cell fractions

Rats, treated for 12 days with chloroquine show a threefold increase of arylsulfatase activity in the mitochondrial-lysosomal mixed fraction, whereas the succinate: cytochrome c reductase activity is decreased to about 50% in this fraction. Purified lysosomes possess a 35 fold higher arylsulfatase activity, compared with homogenate, whereas neither NADPH: - nor succinate: cytochrome c reductase activity can be detected. In these lysosomes, one third of the phospholipids consists of bis (monoacylglycero) phosphate. The neutral phospholipids — mainly phosphatidylethanolamine — are drastically reduced in these cell organelles during the treatment. Our results indicate that chloroquine is nearly exclusively present in the lysosomal fraction. Furthermore we conclude from our data that bis (monoacylglycero) phosphate — isolated from lysosomal phospholipids — forms complexes with chloroquine.     

The incorporation of radioactive fatty acids and of radioactive derivatives of glucose into the phospholipids of subsynaptosomal fractions of cerebral cortex.

1. Crude synaptosomal fractions (P2) from guinea-pig cerebral cortex were incubated in a Krebs-glucose medium containing labelled fatty acids and [3H]glucose. After the shortest incubation period (7.5 min) a high percentage (50-80%) of the total radioactive fatty acids was found in the P2 fractions. 2. After the incubation, the synaptosomal fractions were submitted to hypo-osmotic disruption and subsynaptosomal fractionation was carried out by using discontinuous-sucrose-gradient centrifugation. The specific radioactivities of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were determined in fractions D (synaptic vesicles), E (microsomal preparation) and H (disrupted synaptosomes), as were the specific activities of a number of marker enzymes and the distribution of acetylcholine. 3. By using [14C]oleate, [14C]arachidonate, [3H]palmitate and [3H]glucose, the order to specific radioactivities in fraction D was found to be: phosphatidylinositol greater than phosphatidylcholine greater than phosphatidylserine greater than phosphatidylethanolamine. 4. The specific radioactivities of phosphatidylcholine and phosphatidylethanolamine were always higher in fraction D than in fraction E. As fraction E had higher specific activities of several membrane marker enzymes, the enhanced labelling found in fraction D was considered to be localized in the synaptic vesicles. In this fraction, phosphatidylinositol made particularly large contributions to the total phospholipid labelling derived from [14C]arachidonate and [3H]glucose. 5. The similar labelling ratios of fatty acid/glucose in the phospholipids of fractions D and E, and the high specific radioactivities in the total phospholipid of the soluble fraction O, suggested intrasynaptosomal phospholipid transport.     

The influence of fatty acids on model cholesterol/phospholipid membranes

The aim of this work was to verify the influence of the saturated (SFA) (stearic acid) and the unsaturated (UFA) (oleic and alpha-linolenic) fatty acids on model cholesterol/phospholipid membranes. The experiments were based on the Langmuir monolayer technique. Cholesterol and phospholipid were mixed in the molar ratio that corresponds to the proportion of these lipids in the majority of natural human membranes. Into the binary cholesterol/phospholipid monolayers, various amounts of fatty acids were incorporated. Our investigations were based on the analysis of the interactions between molecules in ternary (cholesterol/phospholipids/fatty acid) mixtures, however, also binary (cholesterol/fatty acid and phospholipids/fatty acid) mixed system were examined. It was concluded that the influence of the fatty acids on model cholesterol/phospholipid membrane is closely connected with the shape of the fatty acid molecule, resulting from the saturation degree of the hydrocarbon chain. It was found that the saturated fatty acid makes the model membrane more rigid, while the presence of unsaturated fatty acid increases its fluidity. The increasing amount of stearic acid gradually destabilizes model membrane, however, this effect is the weakest at low content of SFA in the mixed monolayer. Unsaturated fatty acids in a small proportion make the membrane thermodynamically more stable, while higher content of UFA decreases membrane stability. This explains low proportion of the free fatty acids to other lipids in natural membrane.     

Age-dependent modifications in membrane lipids: lipid composition, fluidity and palmitoyl-CoA desaturase in Tetrahymena membranes

The membrane lipid composition of Tetrahymena pyriformis NT-I was observed to change in a manner markedly dependent on the progress of culture age. The pellicular, mitochondrial and microsomal membranes were isolated from cell harvested at various growth phases (I, early exponential; II, mid-exponential; III, late exponential; IV, early stationary; V, late stationary) and their lipid composition was analyzed by thin-layer and gas-liquid chromatography. Although the phospholipid composition varied somewhat among membrane fractions, the most general age-dependent alteration was a considerable decrease in the content of phosphatidylethanolamine accompanied by a small increase in phosphatidylcholine. The 2-aminoethylphosphonolipid, enriched in the surface membrane pellicle, did not undergo a consistent change. As for fatty acid composition the most notable variation occurred in unsaturated fatty acids; a great increase in oleic and linoleic acids and a compensatory decrease in palmitoleic acid. This resulted in an augmented unsaturation of the overall phospholipid fatty acid profile of the aged membranes. The age-associated drastic decline in the palmitoleic acid content in membrane phospholipids could be accounted for by the markedly lowered activity of palmitoyl-CoA desaturase. The microsomes from the early exponential phase cells possess a 4-fold higher activity of the desaturase as compared to that of the late stationary phase microsomes. The decreased desaturase activity associated with the culture age was also reflected in the corresponding decrease in the conversion rate of [14C]palmitate to [14C]palmitoleate in cells labelled in vivo. The ESR spectra of the spin-labeled phospholipids extracted from the pellicular and microsomal membranes have led to the suggestion that these types of membrane would become more fluid with the age of growth.     

Comparative study of the lipid composition of rabbit and lobster sarcoplasmic reticulum.

Sarcoplasmic reticulum (SR) membranes isolated from rabbit and lobster muscles have similar phospholipid classes, but they differ in plasmalogen content. The plasmalogenic species are mostly distributed among phosphatidylethanolamines (PE's) and make up about 62% of the total in rabbit SR and about 46% in lobster membranes. Lobster SR phospholipids contain large amounts of polyunsaturated fatty acids which are present in low amounts in rabbit membranes. The total unsaturated fatty acids of phosphatidylcholines (PC's) represent about 53% and 73% of the total fatty chains for rabbit and lobster SR, respectively. The values found for PE's were about 56% and 64%, respectively. Furthermore, lobster membranes contain significant amounts of PC and PE molecular species with unsaturated fatty acids in positions 1 and 2, whereas rabbit SR contain low amounts.     

Changes in lipid, fatty acids and phospholipids composition of whole rice bran after solid-state fungal fermentation

The aim of this study was to evaluate fermented rice bran phospholipids, lipids and fatty acid content in a fermentation solid system with Rhizopus oryzae fungus. For this, aliquots were withdrawn every 24h over 120 h. The content of phospholipids was determined by colorimetric method. Esterified fatty acids were separated by gas chromatography, then identified and quantified. The total lipids from fermented rice bran (FB) decreased from 20.4% to 11.2% in the range between 0 h and 120 h of fermentation while phospholipid contents were increased up to 2.4 mg P g(lipid)(-1). In fermented bran, oleic, palmitic and linoleic acids prevailed, with a decrease in saturated fatty acids (20%) and increase in the unsaturated ones (5%). This study showed that rice bran fermentation with R. oryzae can be applied to the production of phospholipids altering the saturated to unsaturated fatty acid ratio.