Essential fatty acids and the brain: possible health implications

Spore germination in Mortierella alpina is associated with a transient depletion of arachidonic acid and induction of fatty acid desaturase gene expression

Mortierella alpina is an oleaginous filamentous fungus whose vegetative mycelium is known to accumulate triglyceride oil containing large amounts of arachidonic acid (ARA 20:4, n - 6). We report that the spores of Mortierella alpina also contain a large proportion of ARA, comprising 50% of total fatty acid. Fatty acid desaturase genes were not expressed in dormant spores but were induced during germination, following a significant drop in the level of ARA (down from 50% of total fatty acid to 12%) prior to germ-tube emergence. We propose that ARA serves as a reserve supply of carbon and energy that is utilised during the early stages of spore germination in Mortierella alpina.

Docosahexaenoic acid synthesis from α-linolenic acid by rat brain is unaffected by dietary n-3 PUFA deprivation

Rates of conversion of alpha-linolenic acid (alpha-LNA, 18:3n-3) to docosahexaenoic acid (DHA, 22:6n-3) by the mammalian brain and the brain's ability to upregulate these rates during dietary deprivation of n-3 polyunsaturated fatty acids (PUFAs) are unknown. To answer these questions, we measured conversion coefficients and rates in post-weaning rats fed an n-3 PUFA deficient (0.2% alpha-LNA of total fatty acids, no DHA) or adequate (4.6% alpha-LNA, no DHA) diet for 15 weeks. Unanesthetized rats in each group were infused intravenously with [1-(14)C]alpha-LNA, and their arterial plasma and microwaved brains collected at 5 minutes were analyzed. The deficient compared with adequate diet reduced brain DHA by 37% and increased brain arachidonic (20:4n-6) and docosapentaenoic (22:5n-6) acids. Only 1% of plasma [1-(14)C]alpha-LNA entering brain was converted to DHA with the adequate diet, and conversion coefficients of alpha-LNA to DHA were unchanged by the deficient diet. In summary, the brain's ability to synthesize DHA from alpha-LNA is very low and is not altered by n-3 PUFA deprivation. Because the liver's reported ability is much higher, and can be upregulated by the deficient diet, DHA converted by the liver from circulating alphaLNA is the source of the brain's DHA when DHA is not in the diet.

Comparison between omega-3 and omega-6 polyunsaturated fatty acid intakes as assessed by a food frequency questionnaire and erythrocyte membrane fatty acid composition in young children

OBJECTIVE

We conducted a dietary validation study in youth aged 1-11 years by comparing dietary intake of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) as assessed by a parent-completed semiquantitative food frequency questionnaire (FFQ) over time to erythrocyte membrane composition of the same fatty acids.

DESIGN

The study population included youth aged 1-11 years who were participants in the Diabetes Autoimmunity Study in the Young (DAISY), a longitudinal study in Denver, Colorado that is following a cohort of youth at risk for developing type I diabetes. Four hundred and four children who had erythrocyte membrane fatty acid data matched to an FFQ corresponding to the same time frame for a total of 917 visits (matches) were included. PUFA intake was expressed both as g/day (adjusted for total energy) and as percent of total fat intake. We used mixed models to test the association and calculate the correlation between the erythrocyte membrane estimates and PUFA intake using all records of data for each youth.

RESULTS

Intakes of total omega-3 fatty acids (beta=0.52, P<0.0001, rho=0.23) and marine PUFAs (beta=1.62, P<0.0001, rho=0.42), as a percent of total fat in the diet, were associated with percent of omega-3 and marine PUFAs in the erythrocyte membrane. Intakes of omega-6 PUFAs (beta=0.04, P=0.418, rho=0.05) and arachidonic acid (beta=0.31, P=0.774, rho=0.01) were not associated.

CONCLUSIONS

In these young children, an FFQ using parental report provided estimates of average long-term intakes of marine PUFAs that correlated well with their erythrocyte cell membrane fatty acid status.

Effect of supplementation with polyunsaturated fatty acids and micronutrients on learning and behavior problems associated with child ADHD

METHODS

Various developmental problems including attention-deficit/hyperactivity disorder (ADHD) have been linked to biological deficiencies in polyunsaturated fatty acids (PUFAs). Additionally, there is evidence that symptoms may be reduced with PUFA supplementation. This study investigated effects of supplementation with PUFAs on symptoms typically associated with ADHD. Because nutrients work synergistically, additional effects of micronutrient supplementation were also investigated. A total of 132 Australian children aged 7 to 12 years with scores > or = 2 SD above the population average on the Conners ADHD Index participated in a randomized, placebo-controlled, double-blind intervention over 15 weeks, taking PUFAs alone, PUFAs + micronutrients, or placebo. Due to unreturned questionnaires, data were only available for 104 children.

RESULTS

Significant medium to strong positive treatment effects were found on parent ratings of core ADHD symptoms, inattention, hyperactivity/impulsivity, on the Conners Parent Rating Scale (CPRS) in both PUFA treatment groups compared with the placebo group; no additional effects were found with the micronutrients. After a one-way crossover to active supplements in all groups for a further 15 weeks, these results were replicated in the placebo group, and the treatment groups continued to show significant improvements on CPRS core symptoms. No significant effects were found on Conners Teacher Rating Scales.

CONCLUSION

These results add to preliminary findings that ADHD-related problems with inattention, hyperactivity, and impulsivity might respond to treatment with PUFAs and that improvements may continue with supplementation extending to 30 weeks.

Fatty acid composition of plasma, medial basal hypothalamus, and uterine tissue in primiparous beef cows fed high-linoleate safflower seeds

The experimental objectives were to evaluate the influence of supplemental high-linoleate safflower seeds on fatty acid concentrations in plasma, medial basal hypothalamus, uterine tissues, and serum 13,14-dihydro-15-keto PGF(2)alpha metabolite (PGFM) in primiparous beef cows during early lactation. Beginning 1 d postpartum, 18 primiparous, crossbred beef cows (411 +/- 24.3 kg of BW) were fed foxtail millet hay at 1.68% of BW (DM basis) and either a low-fat supplement (control: 63.7% cracked corn; 33.4% safflower seed meal; and 2.9% liquid molasses; DM basis) at 0.35% of BW (n = 9) or a supplement (linoleate) containing 95.3% cracked high-linoleate (79% 18:2n-6) safflower seeds and 4.7% liquid molasses (DM basis) at 0.23% of BW (n = 9). Diets were formulated to be isonitrogenous and isocaloric. The linoleate diet contained 5.4% of DMI as fat vs. 1.2% for control. Beginning 1 d postpartum, cattle were bled every 3 d for collection of serum and plasma. Cattle were slaughtered at 37 +/- 3 d postpartum for collection of the medial basal hypothalamus, myometrium, endometrium, caruncular tissue, intercaruncular tissue, and oviduct. Feeding linoleate increased (P = 0.001) plasma concentrations of 18:2n-6, 18:2cis-9 trans-11 and total unsaturated fatty acids; however, 18:1trans-11 did not differ (P = 0.19) between treatments. Concentrations of 20:5n-3 in the medial basal hypothalamus tended (P = 0.10) to be greater for cattle fed linoleate. Concentrations of fatty acids in the oviduct were greater (P < 0.05) than in other uterine tissues. Cows fed linoleate had greater (P = 0.05) concentrations of 18:3n-3 in the endometrium and less (P = 0.06) 18:2cis-9 trans-11 in the myometrium than cows fed the control. Supplemental fat increased (dietary treatment x day postpartum, P = 0.01) concentrations of PGFM in serum more in linoleate than control cows from d 3 to 9 postpartum. Lipid supplementation early in the postpartum period altered the fatty acid composition of medial basal hypothalamus, uterine tissue, and serum concentrations of PGFM. The most novel observation was that the oviduct appeared to be the most sensitive tissue to additional dietary linoleic acid, which could potentially influence fertility.

Docosahexaenoic acid stabilizes soluble amyloid-β protofibrils and sustains amyloid-β-induced neurotoxicity in vitro

Enrichment of diet and culture media with the polyunsaturated fatty acid docosahexaenoic acid has been found to reduce the amyloid burden in mice and lower amyloid-beta (Abeta) levels in both mice and cultured cells. However, the direct interaction of polyunsaturated fatty acids, such as docosahexaenoic acid, with Abeta, and their effect on Abeta aggregation has not been explored in detail. Therefore, we have investigated the effect of docosahexaenoic acid, arachidonic acid and the saturated fatty acid arachidic acid on monomer oligomerization into protofibrils and protofibril fibrillization into fibrils in vitro, using size exclusion chromatography. The polyunsaturated fatty acids docosahexaenoic acid and arachidonic acid at micellar concentrations stabilized soluble Abeta42 wild-type protofibrils, thereby hindering their conversion to insoluble fibrils. As a consequence, docosahexaenoic acid sustained amyloid-beta-induced toxicity in PC12 cells over time, whereas Abeta without docosahexaenoic acid stabilization resulted in reduced toxicity, as Abeta formed fibrils. Arachidic acid had no effect on Abeta aggregation, and neither of the fatty acids had any protofibril-stabilizing effect on Abeta42 harboring the Arctic mutation (AbetaE22G). Consequently, AbetaArctic-induced toxicity could not be sustained using docosahexaenoic acid. These results provide new insights into the toxicity of different Abeta aggregates and how endogenous lipids can affect Abeta aggregation.

The influence of n-6 fatty acid supplemented diet on the effect of imipramine in an animal model of depression

Recent data have shown an association between polyunsaturated fatty acid and depression. This study examined the effect of the supplementation with n-6 fatty acid on the behavior of rats treated with imipramine and submitted to the Forced Swimming Test (FST). Non-supplemented imipramine-treated rats presented a significant reduction of immobility time in the FST whereas n-6 fatty acid-supplemented rats showed a significantly higher immobility time. Imipramine significantly increased norepinephrine plasma concentrations in the two groups. These results show that the diet supplemented with n-6 fatty acid altered the behavior of the animals in the FST, inhibiting the imipramine effect.

Ácidos graxos poliinsaturados ômega-3 e ômega-6: importância e ocorrência em alimentos

Os ácidos graxos poliinsaturados abrangem as famílias de ácidos graxos ômega-3 e ômega-6. Os ácidos graxos de cadeia muito longa, como os ácidos araquidônico e docosaexaenóico, desempenham importantes funções no desenvolvimento e funcionamento do cérebro e da retina. Esse grupo de ácidos graxos não pode ser obtido pela síntese de novo, mas pode ser sintetizado a partir dos ácidos linoléico e alfa-linolênico presentes na dieta. Neste artigo são considerados os principais fatores que podem inibir a atividade das enzimas dessaturases envolvidas na síntese dos ácidos graxos de cadeia muito longa. São apresentadas as recomendações da razão ômega-6/ômega-3 na dieta, propostas em diversos países, sendo verificada a convergência para o intervalo de 4 a 5:1. São relacionados alimentos que podem contribuir para aumentar a ingestão do ácido alfa-linolênico e dos ácidos graxos de cadeia muito longa. A essencialidade dos ácidos graxos de cadeia muito longa é muito dependente do metabolismo do indivíduo, sendo que a razão n-6/n-3 da dieta exerce grande influência nesse sentido.

Therapeutic Options for Cognitive Decline in Senior Pets

Many treatment options are now available for pets with age-related cognitive dysfunction, including drugs, nutritional supplements, and diets. This article describes the theory, evidence of efficacy, and potential neuroprotective effects of products used to treat cognitive dysfunction. Cognitive dysfunction is a diagnosis of exclusion, because many painful conditions and health problems may present with similar signs. Practitioners must, therefore, actively question owners of senior pets in order to diagnose cognitive dysfunction and to assess the pet’s general health and well-being.

D-Amphetamine stimulates D2 dopamine receptor-mediated brain signaling involving arachidonic acid in unanesthetized rats

In rat brain, dopaminergic D(2)-like but not D(1)-like receptors can be coupled to phospholipase A(2) (PLA(2)) activation, to release the second messenger, arachidonic acid (AA, 20:4n-6), from membrane phospholipids. In this study, we hypothesized that D-amphetamine, a dopamine-releasing agent, could initiate such AA signaling. The incorporation coefficient, k* (brain radioactivity/integrated plasma radioactivity) for AA, a marker of the signal, was determined in 62 brain regions of unanesthetized rats that were administered i.p. saline, D-amphetamine (2.5 or 0.5 mg/kg i.p.), or the D(2)-like receptor antagonist raclopride (6 mg/kg, i.v.) before saline or 2.5 mg/kg D-amphetamine. After injecting [1-(14)C]AA intravenously, k* was measured by quantitative autoradiography. Compared to saline-treated controls, D-amphetamine 2.5 mg/kg i.p. increased k* significantly in 27 brain areas rich in D(2)-like receptors. Significant increases were evident in neocortical, extrapyramidal, and limbic regions. Pretreatment with raclopride blocked the increments, but raclopride alone did not alter baseline values of k*. In independent experiments, D-amphetamine 0.5 mg/kg i.p. increased k* significantly in only seven regions, including the nucleus accumbens and layer IV neocortical regions. These results indicate that D-amphetamine can indirectly activate brain PLA(2) in the unanesthetized rat, and that activation is initiated entirely at D(2)-like receptors. D-Amphetamine's low-dose effects are consistent with other evidence that the nucleus accumbens, considered a reward center, is particularly sensitive to the drug.

G protein-coupled receptor systems and their lipid environment in health disorders during aging

Cells, tissues and organs undergo phenotypic changes and deteriorate as they age. Cell growth arrest and hyporesponsiveness to extrinsic stimuli are all hallmarks of senescent cells. Most such external stimuli received by a cell are processed by two different cell membrane systems: receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs). GPCRs form the largest gene family in the human genome and they are involved in most relevant physiological functions. Given the changes observed in the expression and activity of GPCRs during aging, it is possible that these receptors are directly involved in aging and certain age-related pathologies. On the other hand, both GPCRs and G proteins are associated with the plasma membrane and since lipid-protein interactions regulate their activity, they can both be considered to be sensitive to the lipid environment. Changes in membrane lipid composition and structure have been described in aged cells and furthermore, these membrane changes have been associated with alterations in GPCR mediated signaling in some of the main health disorders in elderly subjects. Although senescence could be considered a physiologic process, not all aging humans develop the same health disorders. Here, we review the involvement of GPCRs and their lipid environment in the development of the major human pathologies associated with aging such as cancer, neurodegenerative disorders and cardiovascular pathologies.

Essential polyunsaturated fatty acids in plasma and erythrocytes of children with inborn errors of amino acid metabolism

Essential fatty acids (EFAs), and their longer-chain more-unsaturated derivatives (LCPUFAs) in particular, are essential for normal growth and cognitive development during childhood. Children with inborn errors of amino acid metabolism represent a risk population for a reduced LCPUFA status because their diet is low in EFAs and LCPUFAs. We have investigated the EFA and LCPUFA status of children with various amino acid metabolism disorders (not PKU) under treatment. Fatty acid profiles of plasma and erythrocyte phospholipids of 33 patients (aged 0-18 years) and 38 matched controls were determined by gas-liquid chromatography. Food-frequency questionnaires were used to assess the mean fatty acid intake. The dietary intake of the EFAs linoleic acid (LA) and alpha-linolenic acid (ALA) was comparable in both groups, while the LCPUFA intake was much lower in patients. This was associated with lower relative concentrations (% of total fatty acids) of n-3 docosahexaenoic acid (DHA) in plasma and erythrocyte phospholipids. Concentrations of arachidonic acid (AA) did not differ. The same was observed for the two EFAs LA and ALA. Thus, as compared to healthy controls, children with amino acid metabolism disorders have a lower intake of LCPUFAs and have lower concentrations of DHA but not of AA in plasma and erythrocyte phospholipids. This suggests that endogenous AA synthesis might guarantee an adequate AA status. The lower DHA status, however, warrants further investigations regarding the impact of DHA supplementation on growth and development of these children.

Epidemiology of Parkinson's disease

The causes of Parkinson's disease (PD), the second most common neurodegenerative disorder, are still largely unknown. Current thinking is that major gene mutations cause only a small proportion of all cases and that in most cases, non-genetic factors play a part, probably in interaction with susceptibility genes. Numerous epidemiological studies have been done to identify such non-genetic risk factors, but most were small and methodologically limited. Larger, well-designed prospective cohort studies have only recently reached a stage at which they have enough incident patients and person-years of follow-up to investigate possible risk factors and their interactions. In this article, we review what is known about the prevalence, incidence, risk factors, and prognosis of PD from epidemiological studies.

Determination of phospholipid fatty acids in biological samples by solid-phase extraction and fast gas chromatography

A new method for the determination of phospholipid fatty acids in biological samples, combination of solid-phase extraction (SPE) and fast gas chromatography (GC) was developed. Its application to human plasma and human erythrocytes showed to be robust and reliable for quick and correct identification in routine analysis.

Postmortem brain fatty acid profile of levodopa-treated Parkinson disease patients and parkinsonian monkeys

Fatty acids play a critical role in brain function but their specific role in the pathophysiology of Parkinson disease (PD) and levodopa-induced motor complications is still unknown. From a therapeutic standpoint, it is important to determine the relation between brain fatty acids and PD because the brain fatty acid content depends on nutritional intake, a readily manipulable environmental factor. Here, we report a postmortem analysis of fatty acid profile by gas chromatography in the brain cortex of human patients (12 PD patients and nine Controls) as well as in the brain cortex of monkeys (four controls, five drug-naive MPTP monkeys and seven levodopa-treated MPTP monkeys). Brain fatty acid profile of cerebral cortex tissue was similar between PD patients and Controls and was not correlated with age of death, delay to autopsy or brain pH. Levodopa administration in MPTP monkeys increased arachidonic acid content (+7%; P < 0 .05) but decreased docosahexaenoic acid concentration (-15%; P < 0.05) and total n-3:n-6 polyunsaturated fatty acids ratio (-27%; P < 0.01) compared to drug-naive MPTP animals. Interestingly, PD patients who experienced motor complications to levodopa had higher arachidonic acid concentrations in the cortex compared to Controls (+13.6%; P < 0.05) and to levodopa-treated PD patients devoid of motor complications (+14.4%; P < 0.05). Furthermore, PD patients who took an above-median cumulative dose of levodopa had a higher relative amount of saturated fatty acids but lower monounsaturated fatty acids in their brain cortex (P < 0.01). These results suggest that changes in brain fatty acid relative concentrations are associated with levodopa treatment in PD patients and in a non-human primate model of parkinsonism.

Antioxidants and polyunsaturated fatty acids in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Oligodendrocyte damage and subsequent axonal demyelination is a hallmark of this disease. Different pathomechanisms, for example, immune-mediated inflammation, oxidative stress and excitotoxicity, are involved in the immunopathology of MS. The risk of developing MS is associated with increased dietary intake of saturated fatty acids. Polyunsaturated fatty acid (PUFA) and antioxidant deficiencies along with decreased cellular antioxidant defence mechanisms have been observed in MS patients. Furthermore, antioxidant and PUFA treatment in experimental allergic encephalomyelitis, an animal model of MS, decreased the clinical signs of disease. Low-molecular-weight antioxidants may support cellular antioxidant defences in various ways, including radical scavenging, interfering with gene transcription, protein expression, enzyme activity and by metal chelation. PUFAs may not only exert immunosuppressive actions through their incorporation in immune cells but also may affect cell function within the CNS. Both dietary antioxidants and PUFAs have the potential to diminish disease symptoms by targeting specific pathomechanisms and supporting recovery in MS.

Polyunsaturated fatty acid supplementation during pregnancy alters neonatal behavior in sheep

The objectives of the study were to determine whether supplementation of pregnant ewes with long-chain (n-3) fatty acids present in fish oil, in combination with dietary vitamin E, would alter neonatal behavior in sheep. Twin- (n=36) and triplet- (n=12) bearing ewes were allocated at d 103 of gestation to 1 of 4 dietary treatments containing 1 of 2 fat sources [Megalac, a calcium soap of palm fatty acid distillate or a fish oil mixture, high in 20:5(n-3) and 22:6(n-3)] and 1 of 2 dietary vitamin E concentrations (50 or 500 mg/kg) in a 2 x 2 factorial design. Feeding fish oil increased gestation length by 2 d and increased the proportion of 22:6(n-3) within neonatal plasma by 5.1-fold and brain by 10%, whereas brain 20:5(n-3) was increased 5-fold. Supranutritional dietary vitamin E concentrations decreased the latency of lambs to stand in ewes fed fish oil but not Megalac, whereas latency to suckle was decreased from 43 to 34 min by fish oil supplementation. Supplementation with fish oil also substantially decreased the secretion rate (mL/h) of colostrum and the yield (g/h) of fat and protein. We conclude that supplementation of ewes with fish oil decreases the latency to suckle, increases gestation length and the 22:6(n-3):20:4(n-6) ratio in the neonatal brain, and may improve lamb survival rate. However, further work is required to determine how to mitigate the negative effects of fish oil on colostrum production.

Selective polyunsaturated fatty acids enrichment in phospholipids from neuronal-derived cell lines

Most studies aimed at exploring the molecular and cellular properties of plasma membranes in neural tissues make use of cell lines. However, cell membrane lipid composition of cell lines is notably different from that of brain tissues where they presumably derive from. Using septal-derived SN56 cells and hippocampal-derived HT22 cells, we demonstrated that cell lines exhibit lower contents of saturated (18:0) and long polyunsaturated fatty acids (PUFA; 20:4n-6 and especially 22:6n-3), as well as higher monounsaturated fatty acid contents (mainly 18:1n-9), compared to mouse brain. Also, cell lines exhibited higher contents of sterol esters and lower contents of cholesterol and phospholipids, especially phosphatidylethanolamine and phosphatidylserine. We have also evaluated the effects of different (n-3/n-6) PUFA enrichments on fatty acid and phospholipid contents in these cell lines. Our results show that enrichment of culture medium with 22:6n-3 and 20:4n-6 in a 70/30 proportion during 48 h, using fat-free bovine serum albumin as vehicle, successfully readjusted fatty acid profiles in cell line-polar lipids to values found in natural nerve cells. Interestingly, no differences in cell survival were observed upon enrichment. The generalization of these methodologies would allow a more feasible adaptation of cellular models to the study of in vivo nerve physiology.

Dilinoleoyl-phosphatidylethanolamine from Hericium erinaceum protects against ER stress-dependent Neuro2a cell death via protein kinase C pathway

In many types of neurodegeneration, neuronal cell death is induced by endoplasmic reticulum (ER) stress. Hence, natural products able to reduce ER stress are candidates for use in the attenuation of neuronal cell death and, hence, in the reduction of the damage, which occurs in neurodegenerative disease. In this study, we investigated ER stress-reducing natural products from an edible mushroom, Hericium erinaceum. As a result of screening by cell viability assay on the protein glycosylation inhibitor tunicamycin-induced (i.e., ER stress-dependent) cell death, we found that dilinoleoyl-phosphatidylethanolamine (DLPE) was one of the molecules effective at reducing ER stress-dependent cell death in the mouse neuroblastoma cell line Neuro2a cells. A purified DLPE, commercially available, also exhibited a reducing effect on this ER stress-dependent cell death. Therefore, we concluded that DLPE has potential as a protective molecule in ER stress-induced cell death. From the structure of DLPE, it was hypothesized that it might activate protein kinase C (PKC). The activity of PKC-epsilon, a novel-type PKC, was increased by adding DLPE, and PKC-gamma, a conventional-type PKC, was activated on the coaddition of diolein and DLPE, as shown by in vitro enzyme activity analysis. The protecting activity of DLPE was attenuated in the presence of a PKC inhibitor GF109203X but not completely diminished. Therefore, DLPE can protect neuronal cells from ER stress-induced cell death, at least in part by the PKC pathway.

How does a suicide attempter eat differently from others? Comparison of macronutrient intakes

OBJECTIVE

Issues of the subtle effects of diet and nutrition on suicidal behaviors are rarely examined. This study describes the differences in dietary intakes of macronutrients between individuals who had ever made a suicide attempt and those who never had.

METHODS

We examined the data of 7631 non-institutionalized adults ages 17 to 39 y who completed a mental disorder diagnostic interview and a 24-h dietary recall as a part of the Third National Health and Nutrition Examination Survey, 1988 to 1994. Multivariable adjusted means of daily caloric intake and energy percentage from macronutrients were calculated for individuals who had a history of lifetime suicide attempt(s) (n = 408) and compared with those who did not.

RESULTS

After adjustment for covariates, including socioeconomic indicators, health risk factors, and history of medical and psychiatric illnesses, we observed that the means of daily caloric intake, cholesterol, and energy percentages from carbohydrate, total fat, saturated fat, monounsaturated fat, and protein did not differ significantly between attempters and non-attempters. However, energy percentage from polyunsaturated fat was lower in attempters than in non-attempters. Mean percentages +/- standard error for smoking attempters, non-smoking attempters, smoking non-attempters, and non-smoking non-attempters were 5.5 +/- 0.4 (P = 0.01), 6.7 +/- 0.2 (P = 0.02), 7.5 +/- 1.4 (P = 0.78), and 7.2 +/- 0.1 (reference), respectively, in men, and 6.3 +/- 0.4 (P = 0.01), 7.2 +/- 0.2 (P = 0.07), 7.3 +/- 1.0 (P = 0.89), and 7.5 +/- 0.1 (reference), respectively, in women. Dietary fiber intake was also lower in attempters than in non-attempters. These differences were independent of daily caloric intake.

CONCLUSIONS

Individuals with a history of suicide attempt have low intakes of polyunsaturated fat and fiber. Potential deleterious effects of low intake of polyunsaturated fat and fiber among suicide attempters merit further investigation.

Protective effect of green tea on erythrocyte membrane of different age rats intoxicated with ethanol

It is known that aging is characterized by changes in cell metabolism resulting in modification of the structure and function of cell membrane components which is mainly the consequence of reactive oxygen species action. These disturbances are also enhanced by different xenobiotics, e.g. ethanol. Therefore, the aim of this paper is to examine green tea influence on total antioxidant status (TAS) and on composition and electric charge of erythrocyte membrane phospholipids in ethanol intoxicated rats of various ages. Antioxidant abilities of erythrocytes were estimated by measuring TAS. Qualitative and quantitative composition of phospholipids in the membrane was determined by HPLC, while the extent of erythrocytes lipid peroxidation was estimated by HPLC measurement of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) levels. Electrophoresis was used to determine the surface charge density of the rat erythrocyte membrane. It was shown that the process of aging was accompanied by a decrease in TAS and in the total amount of phospholipids as well as by enhancement of lipid peroxidation and increase in surface charge density of erythrocyte membrane. Ethanol administration caused, in term, decrease in TAS and increase in the level of all phospholipids and lipid peroxidation products. Ethanol as well significantly enhanced changes in surface charge density of erythrocyte membrane. The ingestion of green tea partially prevented decrease in erythrocyte antioxidant abilities observed during aging and ethanol intoxication. Moreover, long-term drinking of green tea protects the structure of the erythrocytes membrane disturbed during aging process and/or chronic ethanol intoxication.

Specific volumes of unsaturated phosphatidylcholines in the liquid crystalline lamellar phase

The specific volumes of seven 1,2-diacyl-sn-glycero-3-phosphocholines with symmetric, unbranched acyl chains containing one, four, or six cis double bonds per chain, or with a saturated sn-1 chain and one, four, or six cis double bonds in the sn-2 chain were determined by the neutral buoyancy method. Experiments were conducted in the liquid crystalline lamellar phase over the temperature range from 5 to 35 degrees C. It is demonstrated that the molecular volume of phosphatidylcholines can be well approximated as the sum of a constant volume of the polar lipid head region and the temperature-dependent volumes of hydrocarbon chain CH2, CH, and terminal CH3 groups. A linear dependence of chain segment volumes on temperature was observed. A self-consistent set of partially temperature-dependent volumes is obtained that allows prediction of phosphatidylcholine molecular volumes within very tight error margins.

D2 but not D1 dopamine receptor stimulation augments brain signaling involving arachidonic acid in unanesthetized rats

RATIONALE AND OBJECTIVES

Signal transduction involving the activation of phospholipase A2 (PLA2) to release arachidonic acid (AA) from membrane phospholipids, when coupled to dopamine D1- and D2-type receptors, can be imaged in rats having a chronic unilateral lesion of the substantia nigra. It is not known, however, if the signaling responses occur in the absence of a lesion. To determine this, we used our in vivo fatty acid method to measure signaling in response to D1 and D2 receptor agonists given acutely to unanesthetized rats.

METHODS

[1-(14)C]AA was injected intravenously in unanesthetized rats, and incorporation coefficients k* for AA (brain radioactivity/integrated plasma radioactivity) were measured using quantitative autoradiography in 61 brain regions. The animals were administered i.v. the D2 receptor agonist, quinpirole (1 mg kg(-1), i.v.), the D1 receptor agonist SKF-38393 (5 mg kg(-1), i.v.), or vehicle/saline.

RESULTS

Quinpirole increased k* significantly in multiple brain regions rich in D2-type receptors, whereas SKF-38393 did not change k* significantly in any of the 61 regions examined.

CONCLUSIONS

In the intact rat brain, D2 but not D1 receptors are coupled to the activation of PLA2 and the release of AA.

α-Linolenic acid does not contribute appreciably to docosahexaenoic acid within brain phospholipids of adult rats fed a diet enriched in docosahexaenoic acid

Adult male unanesthetized rats, reared on a diet enriched in both alpha-linolenic acid (alpha-LNA) and docosahexaenoic acid (DHA), were infused intravenously for 5 min with [1-(14)C]alpha-LNA. Timed arterial samples were collected until the animals were killed at 5 min and the brain was removed after microwaving. Plasma and brain lipid concentrations and radioactivities were measured. Within plasma lipids, > 99% of radioactivity was in the form of unchanged [1-(14)C]alpha-LNA. Eighty-six per cent of brain radioactivity at 5 min was present as beta-oxidation products, whereas the remainder was mainly in 'stable' phospholipid or triglyceride as alpha-LNA or DHA. Equations derived from kinetic modeling demonstrated that unesterified unlabeled alpha-LNA rapidly enters brain from plasma, but that its incorporation into brain phospholipid and triglyceride, as in the form of synthesized DHA, is < or = 0.2% of the amount that enters the brain. Thus, in rats fed a diet containing large amounts of both alpha-LNA and DHA, the alpha-LNA that enters brain from plasma largely undergoes beta-oxidation, and is not an appreciable source of DHA within brain phospholipids.

Improvement of visual functions and fundus alterations in early age-related macular degeneration treated with a combination of acetyl-L-carnitine, n-3 fatty acids, and coenzyme Q10

The aim of this randomized, double-blind, placebo-controlled clinical trial was to determine the efficacy of a combination of acetyl-L-carnitine, n-3 fatty acids, and coenzyme Q10 (Phototrop) on the visual functions and fundus alterations in early age-related macular degeneration (AMD). One hundred and six patients with a clinical diagnosis of early AMD were randomized to the treated or control groups. The primary efficacy variable was the change in the visual field mean defect (VFMD) from baseline to 12 months of treatment, with secondary efficacy parameters: visual acuity (Snellen chart and ETDRS chart), foveal sensitivity as measured by perimetry, and fundus alterations as evaluated according to the criteria of the International Classification and Grading System for AMD. The mean change in all four parameters of visual functions showed significant improvement in the treated group by the end of the study period. In addition, in the treated group only 1 out of 48 cases (2%) while in the placebo group 9 out of 53 (17%) showed clinically significant (>2.0 dB) worsening in VFMD (p = 0.006, odds ratio: 10.93). Decrease in drusen-covered area of treated eyes was also statistically significant as compared to placebo when either the most affected eyes (p = 0.045) or the less affected eyes (p = 0.017) were considered. These findings strongly suggested that an appropriate combination of compounds which affect mitochondrial lipid metabolism, may improve and subsequently stabilize visual functions, and it may also improve fundus alterations in patients affected by early AMD.

Dietary fatty acids and the risk of Parkinson disease: The Rotterdam Study

BACKGROUND

Unsaturated fatty acids are important constituents of neuronal cell membranes and have neuroprotective, antioxidant, and anti-inflammatory properties.

OBJECTIVE

To determine if a high intake of unsaturated fatty acids might be associated with a lower risk of Parkinson disease (PD).

METHODS

In the Rotterdam Study, a prospective population-based cohort study of people ages > or =55, the association between intake of unsaturated fatty acids and the risk of incident PD was evaluated among 5,289 subjects who were free of dementia and parkinsonism and underwent complete dietary assessment at baseline. PD was assessed through repeated in-person examination, and the cohort was continuously monitored by computer linkage to medical records. The data were analyzed using Cox proportional hazards regression models.

RESULTS

After a mean follow-up of 6.0 years, 51 participants with incident PD were identified. Intakes of total fat, monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) were significantly associated with a lower risk of PD, with an adjusted hazard ratio per SD increase of energy-adjusted intake of 0.69 (95% CI 0.52 to 0.91) for total fat, of 0.68 (95% CI 0.50 to 0.94) for MUFAs, and 0.66 (95% CI 0.46 to 0.96) for PUFAs. No associations were found for dietary saturated fat, cholesterol, or trans-fat.

CONCLUSION

These findings suggest that high intake of unsaturated fatty acids might protect against Parkinson disease.

Therapeutic agents for the treatment of cognitive dysfunction syndrome in senior dogs

With increasing age, dogs develop a form of neurodegenerative disease which has many similarities to age related cognitive impairment and Alzheimer's disease in humans. A decline in learning and memory can be demonstrated in dogs beginning as young as 7 years of age using a variety of neuropsychological tests. However, clinical cases of cognitive dysfunction syndrome are seldom identified until the age of 11 years or older. This is likely due to the fact that the owners are relying on clinical observations such as house-soiling, sleep-wake cycles and disorientation, rather than tests of learning and memory. On the other hand, dogs that are trained to more exacting tasks such as guide dogs for the visually impaired, or bomb detection and agility trained dogs might be noticed to have a decline in performance at a much earlier age. Through the use of standardized neuropsychological testing protocols, a number of drugs, natural products and supplement formulations have been developed for use in dogs with cognitive dysfunction and, in some cases clinical trials have validated their efficacy. Furthermore, the testing of products currently licensed and in the pipeline for the treatment of cognitive decline and Alzheimer's in humans, may provide additional therapeutic agents for the treatment of senior dogs, as well as provide insight as to the potential for the efficacy of these compounds in humans. This review will examine those products that are now marketed along with some that might be considered for use in senior dogs with cognitive dysfunction as well as the research that has been used to validate the efficacy (or lack thereof) of these compounds.

Reversing the deleterious effects of aging on neuronal communication and behavior: beneficial properties of fruit polyphenolic compounds

Despite elegant research involving molecular biology studies and determination of the genetic mechanisms of aging, practical information on how to forestall or reverse the deleterious effects of aging may be years away. If this is the case, then it is prudent to try to establish other methods that can be used now to alter the course of aging. Numerous epidemiologic studies have indicated that individuals who consume diets containing large amounts of fruits and vegetables may reduce their risk for developing age-related diseases such as Alzheimer disease. Research from our laboratory suggested that dietary supplementation with fruit or vegetable extracts high in antioxidants (eg, blueberry or spinach extracts) might decrease the enhanced vulnerability to oxidative stress that occurs in aging. These reductions might be expressed as improvements in motor and cognitive behavior. Additional research suggested that mechanisms in addition to antioxidant and antiinflammatory activities might be involved in the beneficial effects of these extracts; the most important of these might be their ability to increase cellular signaling and neuronal communication.

Flavonoids and the brain: interactions at the blood-brain barrier and their physiological effects on the central nervous system

Over the past few years there has been an exponential growth in the number of reports describing the effects of nutritional modulation on aging and age-related diseases. Specific attention has been directed toward the beneficial effects afforded by dietary antioxidants, in particular those from fruit and vegetables, in ameliorating age-related deficits in brain performance. The rationale for studying the effects of dietary intervention stems from evidence implicating free radicals in aspects related to the aging process. Age-dependent neuropathology is a cumulative response to alterations induced by reactive oxygen species. Therefore cognitive aging, according to this hypothesis, should be slowed, and possibly even reversed, by appropriately increasing levels of antioxidants or decreasing overproduction of free radicals in the body.

Essential fatty acids in erythrocyte phospholipids during pregnancy and at delivery in mothers and their neonates: comparison with plasma phospholipids

Evidence that the essential fatty acid (EFA) status during pregnancy and at birth may not be optimal is mainly based on fatty acid profiles of maternal and neonatal plasma phospholipids. However, erythrocyte phospholipids may be more reliable than plasma phospholipids to reflect the EFA status of an individual. Therefore, the present study compares the levels of EFA and of their derivatives (LCPUFA) in erythrocyte and plasma phospholipids collected during pregnancy and at delivery of 184 women and of their infants at birth. In general, the relative concentrations of erythrocyte and plasma phospholipid fatty acids (% of total fatty acids) were strongly correlated, but not at early pregnancy. The overall changes in fatty acid concentrations during pregnancy were qualitatively comparable between erythrocytes and plasma, although the comparability became less towards the end of pregnancy. The changes in absolute amounts (mg/l) of fatty acids in erythrocyte and plasma phospholipids also compare quite well till 32 weeks of gestation, but not thereafter. Most maternal-neonatal differences in relative fatty acid concentrations are qualitatively comparable for erythrocyte and plasma phospholipids. However, significant differences were observed for the absolute amounts of arachidonic and docosahexaenoic acids. No matter these differences, plasma and erythrocyte phospholipids seem equally suitable to reliably quantify the more functional EFA and LCPUFA status based on fatty acid ratios. Correlations between neonatal and maternal fatty acid values at delivery/birth are highly significant in erythrocyte as well as plasma phospholipids. Neonatal erythrocyte (but not plasma) values also correlated strongly with maternal values at early pregnancy. Therefore, the neonatal EFA and LCPUFA status might be predicted on the basis of EFA and LCPUFA concentrations of maternal erythrocyte phospholipids at early pregnancy.

High carbohydrate diets and Alzheimer's disease

Alzheimer's disease (AD) is a common, progressive, neurodegenerative disease that primarily afflicts the elderly. A well-defined risk factor for late onset AD is possession of one or more alleles of the epsilon-4 variant (E4) of the apolipoprotein E gene. Meta-analysis of allele frequencies has found that E4 is rare in populations with long historical exposure to agriculture, suggesting that consumption of a high carbohydrate (HC) diet may have selected against E4 carriers. The apoE4 protein alters lipid metabolism in a manner similar to a HC diet, suggesting a common mechanism for the etiology of AD. Evolutionarily discordant HC diets are proposed to be the primary cause of AD by two general mechanisms. (1) Disturbances in lipid metabolism within the central nervous system inhibits the function of membrane proteins such as glucose transporters and the amyloid precursor protein. (2) Prolonged excessive insulin/IGF signaling accelerates cellular damage in cerebral neurons. These two factors ultimately lead to the clinical and pathological course of AD. This hypothesis also suggests several preventative and treatment strategies. A change in diet emphasizing decreasing dietary carbohydrates and increasing essential fatty acids (EFA) may effectively prevent AD. Interventions that restore lipid homeostasis may treat the disease, including drugs that increase fatty acid metabolism, EFA repletion therapy, and ketone body treatment.

Docosahexaenoic acid protects from dendritic pathology in an Alzheimer's disease mouse model

Learning and memory depend on dendritic spine actin assembly and docosahexaenoic acid (DHA), an essential n-3 (omega-3) polyunsaturated fatty acid (PFA). High DHA consumption is associated with reduced Alzheimer's disease (AD) risk, yet mechanisms and therapeutic potential remain elusive. Here, we report that reduction of dietary n-3 PFA in an AD mouse model resulted in 80%-90% losses of the p85alpha subunit of phosphatidylinositol 3-kinase and the postsynaptic actin-regulating protein drebrin, as in AD brain. The loss of postsynaptic proteins was associated with increased oxidation, without concomitant neuron or presynaptic protein loss. n-3 PFA depletion increased caspase-cleaved actin, which was localized in dendrites ultrastructurally. Treatment of n-3 PFA-restricted mice with DHA protected against these effects and behavioral deficits and increased antiapoptotic BAD phosphorylation. Since n-3 PFAs are essential for p85-mediated CNS insulin signaling and selective protection of postsynaptic proteins, these findings have implications for neurodegenerative diseases where synaptic loss is critical, especially AD.

Effects of fish oil on the central nervous system: a new potential antidepressant?

In the last 100 years major depression has increased worldwide. In this study we provided coconut fat (CF, rich in saturated fatty acids) or fish oil (FO, rich in n-3 polyunsaturated fatty acids) to female rats throughout pregnancy and lactation and then to their offspring post-weaning and examined lipid brain profile and the possible effect of FO as antidepressant agent in the offspring in adulthood (F1). Rats were submitted to forced swimming test, elevated plus maze, Morris water maze and open field. Peroxidation rate in the cerebral cortex and hippocampus were measured. Docosahexaenoic acid (DHA) concentration in dam's milk, eicosapentaenoic acid (EPA) and DHA concentration in hippocampus and cerebral cortex from F1 rats FO supplemented increased significantly when compared to control (C) and CF rats. Arachidonic acid/EPA ratio in the cerebral cortex and hippocampus decreased in rats submitted to forced swimming test. Peroxidation rate were not different between the groups. Immobility time in the forced swimming test in FO group was reduced (p < 0.01) when compared to C and CF rats. We conclude that lifelong intake of FO was able to induce an antidepressant effect with EPA and DHA concentration increased in the cerebral cortex and hippocampus.

Omega-3 fatty acid ethyl-eicosapentaenoate, but not soybean oil, attenuates memory impairment induced by central IL-1β administration

Proinflammatory cytokine interleukin (IL)-1beta can cause cognitive impairment, activate the hypothalamic-pituitary-adrenal axis and impair monoaminergic neurotransmission in the rat. IL-1beta has also been shown to increase the concentration of the inflammatory mediator prostaglandin E2 (PGE2) in the blood. Omega (n)-3 fatty acids, such as eicosapentaenoic acid (EPA), which are components of fish oil, have been shown to reduce both the proinflammatory cytokines and the synthesis of PGE2. The purpose of this study was to determine whether dietary supplements of EPA would attenuate the inflammation-induced impairment of spatial memory by centrally administered IL-1beta. Rats were fed with a diet of coconut oil (contained a negligible quantity of fatty acids), soybean oil (contained mainly n-6 fatty acids), or a diet of coconut oil enriched with ethyl-EPA (E-EPA). The rats were then injected intracerebroventricularly with IL-1beta or saline. The results of this study demonstrated that the IL-1-induced deficit in spatial memory was correlated with an impairment of central noradrenergic and serotonergic (but not dopaminergic) function and an increase in the serum corticosterone concentration. IL-1beta also caused an increase in the hippocampal PGE2 concentration. These effects of IL-1 were attenuated by the chronic administration of E-EPA. By contrast, rats fed with the soybean oil diet showed no effect on the changes induced by the IL-1 administration.

Meat‐Adaptive Genes and the Evolution of Slower Aging in Humans

The chimpanzee life span is shorter than that of humans, which is consistent with a faster schedule of aging. We consider aspects of diet that may have selected for genes that allowed the evolution of longer human life spans with slower aging. Diet has changed remarkably during human evolution. All direct human ancestors are believed to have been largely herbivorous. Chimpanzees eat more meat than other great apes, but in captivity are sensitive to hypercholesterolemia and vascular disease. We argue that this dietary shift to increased regular consumption of fatty animal tissues in the course of hominid evolution was mediated by selection for "meat-adaptive" genes. This selection conferred resistance to disease risks associated with meat eating also increased life expectancy. One candidate gene is apolipoprotein E (apoE), with the E3 allele evolved in the genus Homo that reduces the risks for Alzheimer's and vascular disease, as well as influencing inflammation, infection, and neuronal growth. Other evolved genes mediate lipid metabolism and host defense. The timing of the evolution of apoE and other candidates for meat-adaptive genes is discussed in relation to key events in human evolution.

Altered fatty acid composition of dopaminergic neurons expressing alpha-synuclein and human brains with alpha-synucleinopathies

Alpha-synuclein (alphaS) is an abundant neuronal protein that accumulates in insoluble inclusions in Parkinson's disease (PD) and the related disorder, dementia with Lewy bodies (DLB). A central question about the role of alphaS in the pathogenesis of PD and DLB concerns how this normally soluble protein assembles into insoluble aggregates associated with neuronal dysfunction. We recently detected highly soluble oligomers of alphaS in normal brain supernatants and observed their augmentation in PD and DLB brains. Further, we found that polyunsaturated fatty acids (PUFAs) enhanced alphaS oligomerization in intact mesencephalic neuronal cells. We now report the presence of elevated PUFA levels in PD and DLB brain soluble fractions. Higher PUFA levels were also detected in the supernatants and high-speed membrane fractions of neuronal cells over-expressing wild-type or PD-causing mutant alphaS. This increased PUFA content in the membrane fraction was accompanied by increased membrane fluidity in the alphaS overexpressing neurons. In accord, membrane fluidity and the levels of certain PUFAs were decreased in the brains of mice genetically deleted of alphaS. Together with our earlier observations, these results suggest that alphaS-PUFA interactions help regulate neuronal PUFA levels as well as the oligomerization state of alphaS, both normally and in human synucleinopathies.

Dietary lipids in the aetiology of Alzheimer's disease: implications for therapy

Amyloid plaques and neurofibrillary tangles are the neuropathological hallmarks of Alzheimer's disease (AD), but no conclusive evidence has emerged showing that these hallmarks are the cause and not a product of the disease. Many studies have implicated oxidation and inflammation in the AD process, and there is growing evidence that abnormalities of lipid metabolism also play a role. Using epidemiology to elucidate risk factors and histological changes to suggest possible mechanisms, the hypothesis is advanced that dietary lipids are the principal risk factor for the development of late-onset sporadic AD. The degree of saturation of fatty acids and the position of the first double bond in essential fatty acids are the most critical factors determining the effect of dietary fats on the risk of AD, with unsaturated fats and n-3 double bonds conferring protection and an overabundance of saturated fats or n-6 double bonds increasing the risk. The interaction of dietary lipids and apolipoprotein E isoforms may determine the risk and rate of sustained autoperoxidation within cellular membranes and the efficacy of membrane repair. Interventions involving dietary lipids and lipid metabolism show great promise in slowing or possibly averting the development of AD, including dietary changes, cholesterol-modifying agents and antioxidants.

Effect of a diet-induced n-3 PUFA depletion on cholinergic parameters in the rat hippocampus

Because brain membranes contain large amounts of docosahexaenoic acid (DHA, 22:6n-3), and as (n-3) PUFA dietary deficiency can lead to impaired attention, learning, and memory performance in rodents, we have examined the influence of an (n-3) PUFA-deprived diet on the central cholinergic neurotransmission system. We have focused on several cholinergic neurochemical parameters in the frontal cortex and hippocampus of rats fed an (n-3) PUFA-deficient diet, compared with rats fed a control diet. The (n-3) PUFA deficiency resulted in changes in the membrane phospholipid compositions of both brain regions, with a dramatic loss (62-77%) of DHA. However, the cholinergic pathway was only modified in the hippocampus and not in the frontal cortex. The basal acetylcholine (ACh) release in the hippocampus of deficient rats was significantly (72%) higher than in controls, whereas the KCl-induced release was lower (34%). The (n-3) PUFA deprivation also caused a 10% reduction in muscarinic receptor binding. In contrast, acetylcholinesterase activity and the vesicular ACh transporter in both brain regions were unchanged. Thus, we evidenced that an (n-3) PUFA-deficient diet can affect cholinergic neurotransmission, probably via changes in the phospholipid PUFA composition.

A role for COX-2 and p38 mitogen activated protein kinase in long-term depression in the rat dentate gyrus in vitro

Long-term potentiation (LTP) and long-term depression (LTD) are two forms of activity-dependent synaptic plasticity that are thought to be involved in learning and memory. Evidence has shown that cyclooxygenase-2 (COX-2), an enzyme that converts arachidonic acid to prostaglandins, is expressed in postsynaptic dendritic spines and is regulated by synaptic activity. COX-2 inhibition has been shown to directly attenuate LTP in the dentate gyrus of the hippocampus. Also recently the p38 MAP kinase cascade, a pathway utilised by cells for COX-2 expression, has been implicated in LTD induction in the CA1 region of the hippocampus. Here we demonstrate for the first time a direct role for COX-2 and p38 MAP kinase in LTD and confirm the inhibitory role of COX-2 in LTP in the rat dentate gyrus. Perfusion of the COX-2 inhibitor NS-398 (1 micro M) 60 min before tetanic stimulation resulted in an attenuation of LTD (84+/-5%, n=5 compared to controls of 57+/-7%, n=6, P<0.05). Prolonged exposure (2 h) to NS-398 (1 micro M) resulted in a significant reduction in LTP (71+/-8%, n=5, P<0.01 compared to controls of 170+/-11%, n=5 at 60 min post HFS). The p38 MAPK inhibitor, SB220025 (250 nM) significantly attenuated LTD (88+/-5%, n=7; P<0.01 compared to vehicle controls at 60 min, 56+/-5%, n=6) but had no significant effect on LTP. Both NS-398 and SB220025 had no significant effect on the isolated NMDA-mediated EPSP. These data demonstrate a role for COX-2 and p38 MAPK in LTD in the dentate gyrus in vitro that is independent of NMDA receptor activation.

Arachidonic acid and docosahexaenoic acid suppress thrombin-evoked Ca2+ response in rat astrocytes by endogenous arachidonic acid liberation

Arachidonic (AA) and docosahexaenoic acid (DHA) are the major polyunsaturated fatty acids (PUFAs) in the brain. However, their influence on intracellular Ca2+ signalling is still widely unknown. In astrocytes, the amplitude of thrombin- induced Ca2+ response was time-dependently diminished by AA and DHA, or by the AA tetraynoic analogue ETYA, but not by eicosapentaenoic acid (EPA). Thrombin-elicited Ca2+ response was reduced (20-30%) by 1-min exposure to AA or DHA. Additionally, 1-min application of AA or DHA together with thrombin in Ca2+-free medium blocked Ca2+ influx, which followed after readdition of extracellular Ca2+. EPA and ETYA, however, were ineffective. Long-term treatment of astrocytes with AA and DHA, but not EPA reduced the amplitude of the thrombin-induced Ca2+ response by up to 80%. AA and DHA caused a comparable decrease in intracellular Ca2+ store content. Only DHA and AA, but not EPA or ETYA, caused liberation of endogenous AA by cytosolic phospholipase A2 (cPLA2). Therefore, we reasoned that the suppression of Ca2+ response to thrombin by AA and DHA could be due to release of endogenous AA. Possible participation of AA metabolites, however, was excluded by the finding that specific inhibitors of the different oxidative metabolic pathways of AA were not able to abrogate the inhibitory AA effect. In addition, thrombin evoked AA release via activation of cPLA2. From our data we propose a novel model of positive/negative-feed-back in which agonist-induced release of AA from membrane phospholipids promotes further AA release and then suppresses agonist-induced Ca2+ responses.

Blood lipids, fatty acids, diet and lifestyle parameters in adolescents from a region in northern Norway with a high mortality from coronary heart disease

INTRODUCTION

Students aged 13 and 14 y, in a region in northern Norway with high blood cholesterol levels and high mortality from coronary heart disease (CHD) in the adult population, were studied with respect to lifestyle, dietary habits, nutritional intake and blood lipids including fatty acids in serum. The students came from a coastal community with seawater fish as an important part of the traditional diet, and an inland community with meat from reindeer as a major constituent of the diet.

OBJECTIVE

To investigate whether the traditional diet was maintained among the adolescents and to evaluate the lifestyle and blood lipids. The study was followed up after 1 y.

RESULTS

The adolescents from the coastal region did not maintain the traditional diet. In the inland region the students had a high intake of meat, probably reflecting the traditional food culture. The inland boys had higher mean body mass index (BMI) than the coastal boys, and 12% had BMI>28, as compared to none of the coastal boys. Other findings showed that the students had higher levels of blood cholesterol than in the south of Norway and several other countries (about 25% had total cholesterol >5.2 mmol/l), higher intake of dietary sugar and fat than the national recommendations and little intake of seawater fish with corresponding low levels of n-3 fatty acids. This did not change after 1 y of follow up. Some 10-20% reported daily smoking and 8-13% reported that they rarely or never did physical exercise. About 30% of the students presented no factors negatively related to development of cardiovascular disease.

CONCLUSION

The findings demonstrate, in the majority of students at the age of 13 and 14 y, the appearance of factors contributing to development of cardiovascular disease (CHD).

SPONSORSHIP

This study was supported by the program 'Medisinsk forskning i Finnmark, University of Tromsø'.

Glucose transport and utilization are altered in the brain of rats deficient in n-3 polyunsaturated fatty acids

Long-chain polyunsaturated (n-3) fatty acids have been reported to influence the efficiency of membrane receptors, transporters and enzymes. Because the brain is particularly rich in docosahexaenoic acid (DHA, 22:6 n-3), the present study addresses the question of whether the 22:6 n-3 fatty acid deficiency induces disorder in regulation of energy metabolism in the CNS. Three brain regions that share a high rate of energy metabolism were studied: fronto-parietal cortex, hippocampus and suprachiasmatic nucleus. The effect of the diet deficient in n-3 fatty acids resulted in a 30-50% decrease in DHA in membrane phospholipids. Moreover, a 30% decrease in glucose uptake and a 20-40% decrease in cytochrome oxidase activity were observed in the three brain regions. The n-3 deficient diet also altered the immunoreactivity of glucose transporters, namely GLUT1 in endothelial cells and GLUT3 in neurones. In n-3 fatty acid deficient rats, GLUT1-immunoreactivity readily detectable in microvessels became sparse, whereas the number of GLUT3 immunoreactive neurones was increased. However, western blot analysis showed no significant difference in GLUT1 and GLUT3 protein levels between rats deficient in n-3 fatty acids and control rats. The present results suggest that changes in energy metabolism induced by n-3 deficiency could result from functional alteration in glucose transporters.

Possible anti-Parkinson properties of N-(alpha-linolenoyl) tyrosine: a new molecule

Tyrosine is unable to cross the blood-brain barrier and is therefore unable to improve the status of brain dopamine (DA) and to provide relief for patients with Parkinson's disease (PD) or other DA-insufficient disorders. We report the creation of an amide bond molecule [N-(alpha-linolenoyl)tyrosine (NLT)] that combines tyrosine with a fatty acid mixture. NLT significantly improves the rotational behavior of rats [following unilateral striatal lesions (as a model for Parkinson's)] and overcomes the exaggerated eye-blinking induced by a potent DA-depleting agent (as a model for essential blepharospasm). These results are supported by the finding that NLT's mode of action, in striatum, is the same as the mode of action of D-amphetamine. They both induce an increase in the DA level, DA turnover and release.

The diet-induced proinflammatory state: a cause of chronic pain and other degenerative diseases?

BACKGROUND

It is the rare physician who includes diet therapy and nutritional supplements in patient care. Perhaps this is because chiropractic and medical schools devote very few classroom hours to nutrition. It is also possible that physicians are under the misconception that a detailed biochemical understanding of each individual disease is required before nutritional interventions can be used.

OBJECTIVE

The purpose of this article is two-fold: (1) to demonstrate that chronic pain and other degenerative conditions encountered in clinical practice have similar biochemical etiologies, such as a diet-induced proinflammatory state, and (2) to outline a basic nutritional program that can be used by all practitioners.

DATA SOURCES

The data were accumulated over a period of years by reviewing contemporary articles and books and subsequently by retrieving relevant articles. Articles were also selected through MEDLINE and manual library searches.

RESULTS

The typical American diet is deficient in fruits and vegetables and contains excessive amounts of meat, refined grain products, and dessert foods. Such a diet can have numerous adverse biochemical effects, all of which create a proinflammatory state and predispose the body to degenerative diseases. It appears that an inadequate intake of fruits and vegetables can result in a suboptimal intake of antioxidants and phytochemicals and an imbalanced intake of essential fatty acids. Through different mechanisms, each nutritional alteration can promote inflammation and disease.

CONCLUSION

We can no longer view different diseases as distinct biochemical entities. Nearly all degenerative diseases have the same underlying biochemical etiology, that is, a diet-induced proinflammatory state. Although specific diseases may require specific treatments, such as adjustments for hypomobile joints, beta-blockers for hypertension, and chemotherapy for cancer, the treatment program must also include nutritional protocols to reduce the proinflammatory state.

A study of the behavioral effects of prenatal ethanol exposure in mice fed a diet marginally deficient in essential fatty acids for two generations

This study investigated the effects of prenatal ethanol exposure on measures of fecundity, growth, behavioral development and learning in mice that had been fed a diet, marginal in essential fatty acid (EFA) content for two generations. The first generation of mice were fed one of two diets (adequate or marginal EFA) from conception. They were mated at 10 weeks, and from days 5 to 17 of gestation dams on each diet were fed equivalent daily amounts of a liquid diet containing either 22.5% of the calories as ethanol or with maltose-dextrin substituted isocalorically for ethanol. An additional control group was fed lab chow ad libitum. Offspring were maintained on their respective diets after weaning. The marginal-EFA diet led to a large increase in perinatal mortality; it also decreased body and brain weight in the surviving pups, and retarded behavioural development. Ethanol retarded behavioral development in females, and delayed the acquisition of learning the position of an escape platform in a T water-maze in the mice fed the adequate-EFA diet. The effects of ethanol did not appear to be worse in the mice fed the marginal-EFA diet, but these data must be considered in light of the high mortality on this diet, where only the healthiest pups may have survived.