Effect of omega-3 fatty acid-containing phospholipids on blood catecholamine concentrations in healthy volunteers: a randomized, placebo-controlled, double-blind trial

OBJECTIVE

We previously reported that administration of fish oil rich in docosahexaenoic acid (DHA) increased the plasma ratio of epinephrine to norepinephrine (NE) at rest in young adults who were under chronic stress and that this effect was achieved mainly through depression of NE. However, not many reports have documented the effects of eicosapentaenoic acid (EPA) and DHA on blood catecholamine levels in healthy humans. Therefore, we performed another intervention study to test their effect on catecholamines with healthy subjects under no chronic stress.

METHODS

Twenty-one healthy young adults (15 men and 6 women) were randomly assigned to an omega-3 group (n = 9) or a control group (n = 12) in a double-blind manner. Twenty capsules of shellfish-derived lipids containing 762 mg of EPA plus DHA per day were administered to the omega-3 group for 2 mo. The controls took the same amount of placebo capsules. Fasting blood samples after a 30-min rest with a catheter in a forearm vein were obtained at the start and the end of the study for catecholamine measurements.

RESULTS

EPA but not DHA concentrations in red blood cells significantly increased in the omega-3 group compared with the control group (P < 0.001). Plasma NE concentrations were significantly decreased in the omega-3 group (from 1.49 +/- 0.39 nmol/L to 1.05 +/- 0.14 nmol/L) compared with the control group (from 1.12 +/- 0.24 nmol/L to 1.39 +/- 0.32 nmol/L) with analysis of covariance (P < 0.001). The differences remained significant (P = 0.01) even after deletion of three subjects in the omega-3 group who had the highest baseline NE values and one in the control group who had the lowest baseline NE value to nullify a significant baseline differences in NE between groups.

CONCLUSION

This study demonstrated that EPA plus DHA supplementation lowered plasma NE concentrations in normal volunteers even at the small dose of 762 mg of EPA plus DHA per day. This effect of EPA plus DHA to lower plasma NE concentrations may be important to understand some of the effects of fish oils on diseases.

Effects of eicosapentaenoic acids on oxidative stress and plasma fatty acid composition in patients with lupus nephritis

Eicosapentaenoic acid (EPA) is one of the major components of fish oil, which was reported to have antiatherogenic, anti-inflammatory and immune suppressive effects. In the present study, highly purified EPA was administered to patients with lupus nephritis and the effects of EPA on urinary 8-isoprostane, a reliable marker of oxidative stress, were investigated in these patients. Six outpatients (1 man and 5 women), with lupus nephritis diagnosed by renal biopsy, were entered in the study. We administered 1800 mg EPA ethyl-ester (purity > 95%) daily and examined the urinary 8-isoprostane levels and plasma fatty acid composition before and 3 months after EPA treatment. The urinary 8-isoprostane levels were significantly decreased after the treatment compared with those before the treatment (from 530 +/- 113 pg/mg x Cr to 235 +/- 49 pg/mg x Cr, p = 0.02). The EPA levels in the plasma phospholipid (PL) fraction were significantly increased after the treatment (from 3.30 +/- 0.64 mol% to 8.01 +/- 0.47 mol%, p < 0.001). Arachidonic acid (AA) levels in the plasma PL fraction were significantly decreased after the treatment (from 9.47 +/- 0.28 mol% to 7.33 +/- 0.43 mol%, p < 0.001). The ratios of EPA to AA were significantly increased after the treatment (from 0.35 +/- 0.07 to 1.14 +/- 0.16, p < 0.001). Thus, this preliminary study indicated that EPA might exert beneficial effects on lupus nephritis by decreasing the oxidative stress.

The effect of fish oil on physical aggression in schoolchildren--a randomized, double-blind, placebo-controlled trial

OBJECTIVES

The aim of the study was to investigate whether fish oil supplementation affected Japanese schoolchildren's behavior, with changes in aggression over time as the primary endpoint.

DESIGN AND SUBJECTS

A placebo-controlled double-blind study with 166 schoolchildren 9-12 years of age was performed. The subjects of the fish oil group (n=83) took fish oil-fortified foods (bread, sausage and spaghetti). These foods were provided in amounts such that each subject in the fish oil group had an intake of 3600 mg of docosahexaenoic acid+840 mg of eicosapentaenoic acid (EPA)/week for 3 months. The rest (the controls, n=83) took control supplements. At the start and end of the study, psychological tests were performed to assess their aggression.

RESULTS

Physical aggression assessed by Hostility-Aggression Questionnaire for Children in girls increased significantly (median: 13 to 15, n=42) in the control group and did not change (13 to 13, n=43) in the fish oil group with a significant intergroup difference (P=.008) with baseline as covariate. The changes in physical aggression scores over time and those of the ratio of EPA/arachidonic acid in RBC (DeltaEPA/AA) were significantly correlated in girls who agreed to blood collection (r=-.53, P=.01, n=23). On the contrary, there were no significant changes in physical aggression in boys. Aggression against others (extraggression) assessed by Picture Frustration Study did not change in the control group (median: 5 to 5) but increased significantly in the fish oil group (4 to 5) with a significant intergroup difference (P=.02) with baseline as covariate. These changes in extraggression might be explained partly by significantly lower baseline values of extraggression in the fish oil group (P=.02) than in the control group. There were no significant correlations between Deltaextraggression and DeltaEPA/AA in blood-sampled children (n=49). Impulsivity of girls assessed by parents/guardians using the diagnostic criteria for attention deficit/hyperactivity disorder of DSM-IV was reduced in the fish oil group (1 to 0) with a significant (P=.008) intergroup difference from the control group (1 to 1). There were no significant correlations between Deltaimpulsivity and DeltaEPA/AA in blood-sampled girls. In males, impulsivity reduced in both groups without any intergroup differences.

CONCLUSION

There is a possibility that changes in fatty acid nutrition might affect physical aggression especially in girls.

Effects of cilostazol on lipid and fatty acid metabolism

Cilostazol is a selective inhibitor of phosphodiesterase III with anti-platelet-aggregatory and vasodilating properties. Randomised, double-blind, placebo-controlled trials in 2702 patients with intermittent claudication demonstrated that cilostazol significantly increased walking distances compared with placebo. Furthermore, the agent has beneficial effects on the serum lipid profile and fatty acid composition in plasma. Consequently, cilostazol may be useful to prevent atherosclerosis from progressing by ameliorating lipid and fatty acid metabolism.

Dietary Supplementation with n-3 Polyunsaturated Fatty Acids Attenuates the Depression of Food-Motivated Behavior during Zymosan-Induced Peritonitis

Peripheral inflammation is accompanied by neurobehavioral alterations such as depression of feeding, exploratory and sexual behaviors. Our previous investigation reported that dietary enrichment with n-3 polyunsaturated fatty acids (PUFA) attenuated the depression of food-motivated behavior and social exploration, but not endocrinological and metabolic disturbances in the mice with systemic inflammation induced by lipopolysaccharide (LPS). We here demonstrate that dietary n-3 PUFA also attenuate the reduction of food-motivated behavior during zymosan-induced peritonitis in mice without influencing plasma leakage into peritoneum and writhing response. Our results suggest that the common mechanism is involved in the attenuation of behavioral depression during systemic and local inflammation by dietary n-3 PUFA.

Baicalein 5,6,7-trimethyl ether, a flavonoid derivative, stimulates fatty acid β-oxidation in skin fibroblasts of X-linked adrenoleukodystrophy

The purpose of the present study is to identify bioactive compounds with potential for X-linked adrenoleukodystrophy (X-ALD) pharmacological therapy. Various plant natural products including flavonoids were tested for their ability to ameliorate the abnormality of very long chain fatty acid (VLCFA) metabolism in cultured skin-fibroblasts from X-ALD patients. Of the compounds tested, baicalein 5,6,7-trimethyl ether (baicalein-tri-Me) was found to significantly stimulate the VLCFA beta-oxidation activity. Furthermore, the incorporation of [1-(14)C]lignoceric acid into cholesteryl esters was markedly reduced towards the normal level and the VLCFA (C24:0 and C26:0) content was decreased. These results make baicalein-tri-Me a candidate for the therapeutic compound for X-ALD.

Suicide attempt and n-3 fatty acid levels in red blood cells: a case control study in China

BACKGROUND

Epidemiologic studies show that low fish intake is a risk factor of suicidality; however, there are no case-control studies investigating suicide attempt risk and tissue n-3 fatty acid levels.

METHODS

We recruited 100 suicide-attempt cases and another 100 control patients injured by accidents who were admitted to three hospitals affiliated with Dalian Medical University in Dalian, China. Case and control subjects were matched for age, gender, and smoking status. Those who were inebriated at the time of hospitalization were excluded. Blood was sampled immediately after admission to a hospital. Washed red blood cells (RBCs) were obtained, and the fatty acid composition of the total RBC phospholipid fraction was analyzed by gas chromatography.

RESULTS

Eicosapentaenoic acid (EPA) levels in RBC in the case subjects were significantly lower than those of the control subjects (.74 +/-.52% vs. 1.06 +/-.62%, p <.0001). When the highest and lowest quartiles of EPA in RBC were compared, the odds ratios of suicide attempt was.12 in the highest quartile (95% confidence interval:.04-.36, p for trend =.0001) after adjustment for possible confounding factors

CONCLUSIONS

Our findings suggest that low n-3 fatty acid levels in tissues were a risk factor of suicide attempt. Further studies including intervention with fish oil are warranted.

Dietary n-3 fatty acids selectively attenuate LPS-induced behavioral depression in mice

Systemic administration of bacterial lipopolysaccharide (LPS) induces a series of physiological and pathological alterations as well as behavioral depression in experimental animals. These alterations induced by LPS administration are known to be mediated by endogenous cytokines and arachidonate metabolites, which may be modulated by dietary n-3 fatty acids. Mice were fed a diet supplemented with n-3 or n-6 fatty acids for 4 weeks prior to LPS administration. Food-motivated behavior after intraperitoneal administration of LPS as compared with that before LPS administration was significantly depressed in the mice fed with the n-6 fatty-acid-rich diet (47% to 85% reduction; P<.05) but not significantly in the mice fed with the n-3 fatty-acid-rich diet. Depression of social exploration by intraperitoneal LPS administration in the n-3 fatty-acid-rich diet group (39% reduction vs. vehicle group) was significantly less in the n-6 fatty-acid-rich diet group (76% reduction vs. vehicle group; P<.05). The behavioral depressions induced by intracerebroventricular LPS injection were not significantly different between the two dietary groups (P=.60). The elevation of serum corticosterone and the hypoglycemic response following intraperitoneal LPS administration were not significantly different between the two dietary groups (P=.57 and P=.43, respectively). We demonstrate that dietary n-3 fatty acids attenuate behavioral depression in mice peripherally administered with LPS without affecting the increase in serum corticosterone and the decrease in serum glucose concentration.

Effect of docosahexaenoic acid-containing food administration on symptoms of attention-deficit/hyperactivity disorder - a placebo-controlled double-blind study

OBJECTIVES

To investigate whether docosahexaenoic acid (DHA) supplementation was able to ameliorate attention-deficit/hyperactivity disorder(AD/HD) symptoms in AD/HD children.

DESIGN AND SUBJECTS

A placebo-controlled double-blind study with 40 AD/HD (including eight AD/HD-suspected) children of 6-12 y of age who were mostly without medication. Subjects of a DHA group (n=20) took active foods containing fish oil (fermented soybean milk, bread rolls and steamed bread; 3.6 g DHA/week from these foods) for 2 months, whereas those of a control group (n=20) took indistinguishable control foods without fish oil. The following items were measured at the start and end of the study: (1) attention deficit, hyperactivity and impulsivity (AD/HD-related symptoms according to DSM-IV criteria); (2) aggression assessed by both parents and teachers; (3) visual perception (finding symbols out of a table); (4) visual and auditory short-term memory; (5) development of visual-motor integration; (6) continuous performance; (7) impatience.

RESULTS

Changes in tests 1, 2, 3, 5 and 7 over time did not significantly differ between the two groups. However, visual short-term memory and errors of commission (continuous performance) significantly improved in the control group compared with the changes over time in the DHA group (P=0.02 and 0.001, respectively). Recalculation without AD/HD-suspected subjects (n=4 each group) showed similar P-values with regard to both measures.

CONCLUSION

DHA supplementation did not improve AD/HD-related symptoms. Treatment of ADHD with fatty acids deserves further investigation, but careful attention should be paid as to which fatty acid(s) is used.

Effect of Dietary Enrichment with n-3 Polyunsaturated Fatty Acids (PUFA) or n-9 PUFA on Arachidonate Metabolism in Vivo and Experimentally Induced Inflammation in Mice

Mice were fed a diet supplemented with palm oil (control diet), n-3 polyunsaturated fatty acids (PUFA)-, or n-9 PUFA-rich oil for 3 weeks. The n-3 PUFA-rich diet suppressed the generation of both leukotrienes (LT) and prostaglandins (PG), but the n-9 PUFA-rich diet did LT but not PG generation during acute inflammation. Leukocyte accumulation during acute inflammation was not different in the n-3 or n-9 PUFA-rich diet group as compared with the control group. The n-3 PUFA-rich diet but not the n-9 PUFA-rich diet suppressed Freund's adjuvant-induced granuloma formation. The n-9 PUFA-rich diet significantly attenuated galactosamine/lipopolysaccharide-induced liver injury more effectively than the n-3 PUFA-rich diet as compared with the control diet. The present study revealed the differential modification of experimentally induced inflammation in mice by dietary n-3 PUFA and n-9 PUFA, which may be due to their different effects on 5-lipoxygenease and cyclooxygenase metabolism of arachidonic acid during inflammatory processes.

Cooperative induction of 15-lipoxygenase in rheumatoid synovial cells by IL-4 and proinflammatory cytokines

OBJECTIVE

To clarify the role of interleukin-4 (IL-4) in the expression of 15-lipoxygenase (15-LOX), whose metabolities are known to suppress the inflammatory reaction, in freshly prepared rheumatoid synovial cells.

METHODS

Adherent synovial cells were prepared by enzymatic digestion of synovia obtained from patients with rheumatoid arthritis (RA). Protein expression of 15-LOX was determined by Western blot analysis. The messenger RNAs of 15-LOX were determined by reverse transcription and the polymerase chain reaction (RT-PCR).

RESULTS

Freshly prepared rheumatoid synovial cells did not express 15-LOX at either the mRNA or protein levels. IL-4 induced the protein expression of 15-LOX after 24 hours of culture. Although interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha), major inflammatory cytokines in rheumatoid synovia, did not induce the expression of 15-LOX, IL-4 and these inflammatory cytokines synergistically enhanced the protein expression of 15-LOX. The synergistic effect was also observed at the level of mRNA.

CONCLUSIONS

We demonstrate that IL-4 cooperated with the inflammatory cytokines IL-1 alpha and TNF alpha to enhance the expression of 15-LOX in rheumatoid synovial cells. Since 15-LOX metabolites have potent anti-inflammatory actions, our data suggest that IL-4 might downregulate rheumatoid inflammation via the induction of 15-LOX and its metabolites.

n-3 Polyunsaturated fatty acid (PUFA) deficiency elevates and n-3 PUFA enrichment reduces brain 2-arachidonoylglycerol level in mice

2-arachidonoylglycerol (2-AG) is a putative endogenous ligand for cannabinoid receptors and was suggested to play an important role in both physiological and pathological events in the central nervous system (CNS) as well as in peripheral organs. The sequential hydrolysis of arachidonic acid (20:4n-6, AA)-containing phospholipids has been proposed as a major biosynthetic route of 2-AG. On the other hand, the manipulation of the dietary n-3 polyunsaturated fatty acid (PUFA) status changes the AA level in tissue phospholipids. We, therefore, conducted two separate experiments to confirm whether the dietary n-3 PUFA status influences the 2-AG level in the mouse brain. In the first experiment, we fed mice with n-3 PUFA-deficient diet, which resulted in a marked decrease in the docosahexaenoic acid (22:6n-3, DHA) levels without a change in the AA level in brain phospholipids as compared with the mice fed with an n-3 PUFA-sufficient diet. The brain 2-AG level in the n-3 PUFA-deficient group was significantly higher than in the n-3 PUFA sufficient group. In the second experiment, we found that short-term supplementation of DHA-rich fish oil reduced brain 2-AG level as compared with the supplementation with low n-3 PUFA. The decrease in the AA level and the increase in the DHA level in the major phospholipids occurred in the brains of the mice fed the fish oil diet compared with those fed the low n-3 PUFA diet. Our results indicate that the n-3 PUFA deficiency elevates and n-3 PUFA enrichment reduces the brain 2-AG level in mice, suggesting that physiological and pathological events mediated by 2-AG through cannabinoid receptor in the CNS could be modified by the manipulation of the dietary n-3 PUFA status.

n-3 long-chain FA decrease serum levels of TG and remnant-like particle-cholesterol in humans

A large number of papers have reported that administration of n-3 FA reduced serum TG concentrations in hypertriglyceridemic patients. However, few studies have examined the effect of n-3 FA on serum concentrations of remnant-like particle (RLP) cholesterol. Volunteers (n = 41) whose serum TG concentrations were 100-300 mg/dL were recruited and randomly assigned to either an n-3 FA group or a control group with stratification by sex, age, and serum TG level in a double-blind manner. The subjects in the n-3 FA group were administered 125 mL of fermented soybean milk with fish oil containing 600 mg of EPA and 260 mg of DHA/d for 12 wk. The controls consumed control soybean milk with olive oil. Fasting blood samples were obtained before the start of administration and at 4, 8, and 12 wk. EPA concentrations in red blood cells increased significantly in all but one subject in the n-3 FA group, with no significant changes in the control group. TG levels decreased more in the n-3 FA group than in the control group at weeks 4 (P < 0.05), 8 (P < 0.01), and 12 (P < 0.05) with their baseline as covariate. RLP cholesterol levels decreased more in the n-3 FA group than in the control at weeks 8 (P < 0.01) and 12 (P < 0.05) with their baseline as covariate. The groups did not differ in the other lipid levels. It is likely that n-3 long-chain FA may exert anti-atherosclerotic effects by lowering serum TG and RLP-cholesterol levels even at the dose of 860 mg/d.

Effects of cilostazol on serum lipid concentrations and plasma fatty acid composition in type 2 diabetic patients with peripheral vascular disease

Cilostazol is an anti-thrombotic and vasodilating agent, reported to have both anti-thrombotic and cerebral vasodilating effects. We investigated the effects of cilostazol on serum lipid concentrations and plasma fatty acid composition in type 2 diabetic patients with peripheral vascular disease. The serum concentrations of total cholesterol, triglycerides, high-density lipoprotein-cholesterol, lipoprotein (a), remnant-like particles-cholesterol, apolipoproteins, and plasma fatty acid composition were measured in 17 diabetic patients with peripheral vascular disease before and 1, 3, and 6 months after administration of cilostazol (200 mg/day). Serum triglyceride concentrations were significantly decreased after cilostazol (from 1.31+/-0.17 mmol/l to 0.86+/-0.07 mmol/l at 6 months, P<0.01). Plasma docosahexaenoic acid levels were significantly increased after cilostazol (4.11+/-0.26% to 4.94+/-0.26% at 6 months, P<0.01). Our findings show that cilostazol can induce some beneficial changes in serum lipid profile and plasma fatty acid composition.

The effect of docosahexaenoic acid on aggression in elderly Thai subjects--a placebo-controlled double-blind study

Docosahexaenoic acid (DHA) administration controls extraggression (aggression against others) in young subjects under psychological stress. However, it is not known whether its administration affects extraggression of elderly subjects. Forty Thai subjects of 50-60 years of age (22 males and 18 females) were recruited from Silpakorn University and nearby villages. They were allocated to the control and DHA groups in a double-blind fashion, and took 10 mixed plant oil capsules and 10 DHA capsules (1.5g DHA/day) for 2 months, respectively. Extraggression was measured with a psychological test (PF Study) at the beginning and end of the study. Just prior to the PF Study at the end of the study, subjects were asked to watch a stressful videotape as a stressor component. The average DHA intake from food was 150-160mg/day. In the group of university employees, extraggression did not change over time with placebo, whereas extraggression significantly decreased (31 +/- 13 to 24 +/- 13%, P = 0.04 by the paired-t test, P = 0.04 by ANOVA). In the group of villagers, there was no significant difference between the control and DHA groups in extraggression. The DHA administration favorably controlled extraggression in at least elderly white-collar workers. The daily intake of 150-160 mg/day of DHA was not enough to control extraggression.

Helicobacter pylori alters n-6 fatty acid metabolism and prostaglandin E2 synthesis in rat gastric mucosal cells

BACKGROUND AND AIMS

Little is known about whether Helicobacter pylori infection alters fatty acid metabolism in gastric mucosal cells. By using cultured rat gastric mucosal cells (RGM-1), we investigated the effect of H. pylori broth culture filtrates on this point. Furthermore, our study aimed to find out whether n-6 long chain polyunsaturated fatty acids from linoleic acid are formed in RGM-1 cells.

METHODS

Rat gastric mucosal cells were incubated with 10, 20 and 40 microg/mL of linoleic acid or medium alone. Phosphatidylcholine content extracted from whole RGM-1 cells was quantitated by using a densitometer, and its fatty acid composition was analyzed by using gas chromatography. Prostaglandin E2 concentration in the culture medium was measured by using radioimmunoassay. The expression of cyclooxygenase (COX)-1 and COX-2 was examined by using reverse transcription-polymerase chain reaction. In addition, after incubation with [1-14C] linoleic acid, radioactivities of both linoleic acid and arachidonic acid components of the PC fraction were counted. The effects of H. pylori broth culture filtrates on PC content, its fatty acid composition and prostaglandin (PG)E2 synthesis were also assessed.

RESULTS

Linoleic acid addition caused an increase in the composition of arachidonic acid, as well as linoleic acid, and also in PGE2 concentration. Cyclo-oxygenase-2 expression was induced in RGM-1 cells by the addition of linoleic acid. In addition, [1-14C] linoleic acid added to the culture medium was converted to [1-14C] arachidonic acid in RGM-1 cells. Helicobacter pylori broth culture filtrates decreased linoleic acid composition and increased arachidonic acid composition. Moreover, after incubation with H. pylori broth culture filtrates, PGE2 concentrations were higher than that of the controls.

CONCLUSIONS

These findings suggest the presence of fatty acid elongase and Delta5- and Delta6-desaturases synthesize arachidonic acid from linoleic acid in RGM-1 cells. Thus, H. pylori infection may enhance PGE2 synthesis and accelerate n-6 fatty acid metabolism in gastric mucosal cells, which could make the gastric mucosal barrier more fragile.

Studies on the effects of microgravity on the ultrastructure and function of cultured mammalian cells

Four cultures of monkey kidney cell line, JTC-12, were flown on the Spacelab-J (SL-J) mission during 8 days. The results of the present study showed that the space flight gave no essential effect on morphology, cell cycle, glucose consumption and urokinase production of the mammalian culture cell. However, the cell proliferation slightly decreased under microgravity. Moreover, the lack of gravity induced the trypsin-treated dissociated cells to keep floating in the culture medium. Therefore, the attachment of the cells onto the substratum was delayed, and that caused difficulties in subculturing the cells. The present research also offered some important information on techniques for establishment of cell cultures in space laboratories.

Suppression of platelet-activating factor generation and modulation of arachidonate metabolism by dietary enrichment with (n-9) eicosatrienoic acid or docosahexaenoic acid in mouse peritoneal cells

Several studies have shown that dietary n-3 polyunsaturated fatty acids (PUFAs) suppress platelet-activating factor (PAF) generation in leukocytes of humans and rodents, which is associated with the antagonism of arachidonic acid metabolism. Dietary eicosatrienoic acid (20:3n-9, ETrA) is also suggested to antagonize arachidonic acid (AA) metabolism, but its effect on PAF generation in leukocytes has not been defined. In the present study, we investigated the effects of an ETrA-rich diet on PAF generation and AA metabolism in mouse peritoneal cells, which were compared with those of a docosahexaenoic acid (DHA)-rich diet. Mice were fed a diet supplemented with a lipid preparation rich in ETrA, a DHA-rich fish oil (FO) or palm oil (PO) for 3 weeks, and peritoneal cells containing more than 80% of monocytes/macrophages were obtained. The peritoneal cells in the DHA and ETrA diet groups generated upon zymosan stimulation a smaller amount of PAF than cells in the PO diet group. In the peritoneal cells of the DHA diet group, AA contents in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were significantly lower than those in cells of the PO diet group, but those in phosphatidylinositol (PI) were not significantly different between the two dietary groups. A considerable amount of ETrA was incorporated into the peritoneal cells of the ETrA diet group, and AA was reduced as compared with the PO diet group. These changes occurred preferentially in PI but to a less extent in PC and PE. The amount of free AA released by the peritoneal cells upon zymosan stimulation was significantly reduced in the DHA diet group as compared with that in the PO diet group, whereas AA release was similar between the PO and ETrA diet groups. In conclusion, the effects of dietary ETrA on AA content in the phospholipid subclasses and AA release were quite different from those of dietary DHA, although both diets suppressed PAF generation in mouse peritoneal cells to a similar extent.

Hepatic maturation in differentiating embryonic stem cells in vitro

We investigated the potential of mouse embryonic stem (ES) cells to differentiate into hepatocytes in vitro. Differentiating ES cells expressed endodermal-specific genes, such as alpha-fetoprotein, transthyretin, alpha 1-anti-trypsin and albumin, when cultured without additional growth factors and late differential markers of hepatic development, such as tyrosine aminotransferase (TAT) and glucose-6-phosphatase (G6P), when cultured in the presence of growth factors critical for late embryonic liver development. Further, induction of TAT and G6P expression was induced regardless of expression of the functional SEK1 gene, which is thought to provide a survival signal for hepatocytes during an early stage of liver morphogenesis. The data indicate that the in vitro ES differentiation system has a potential to generate mature hepatocytes. The system has also been found useful in analyzing the role of growth factors and intracellular signaling molecules in hepatic development.

Effect of pedological characteristics on aqueous soil extraction recovery and tert-butyldimethylsilylation yield for gas chromatography-mass spectrometry of nerve gas hydrolysis products from soils

Detection and identification of alkyl methylphosphonate (RMPA) and methylphosphonate (MPA) are performed to verify the existence of nerve gases by gas chromatography-mass spectrometry (GC-MS) after tert-butyldimethylsilylation (TBDMS). However, it is sometimes difficult to detect RMPA and MPA in soils. This study examines the relationship between the pedological characteristics and the aqueous extraction recoveries and TBDMS derivatization yields of ethyl-, isopropyl- and pinacolyl methylphosphonate and MPA for 21 soil samples. The aqueous extraction recoveries were measured directly by capillary electrophoresis. Andosols showed low extraction recoveries, while Regosols and Fluvisols showed high recoveries. RMPA were extracted with higher recoveries than MPA from all soils. MPA could not be extracted from Andosols. Within the pedological characteristics, phosphate absorption coefficients showed a strong negative correlation with the extraction recoveries of all phosphonates. The levels of RMPA and MPA in aqueous soil extracts were also determined for eight soils by GC-MS after TBDMS. Compared to the aqueous extraction recoveries, the yields of TBDMS derivatives were low. Strong anion exchange led to a significant improvement in derivatization yields. The efficiencies of TBDMS derivatization were inversely correlated with the levels of alkaline earth metals extractable from soils when the three soils that possessed high total carbon were excluded.