Peripheral deficiency and antiallodynic effects of 2-arachidonoyl glycerol in a mouse model of paclitaxel-induced neuropathic pain.

BACKGROUND: Modulation of the endocannabinoid system has been shown to alleviate neuropathic pain. The aim of this study was to evaluate if treatment with paclitaxel, a chemotherapeutic agent that induces neuropathic pain, affects endocannabinoid levels at a time when mice develop paclitaxel-induced mechanical allodynia. We also evaluated the peripheral antiallodynic activity of the endocannabinoid 2-arachidonoyl glycerol (2-AG) and an inhibitor of monoacylglycerol lipase (MAGL), an enzyme responsible for 2-AG hydrolysis. METHODS: Female BALB/c mice were treated intraperitoneally with paclitaxel to induce mechanical allodynia. Levels of the endocannabinoids, N-arachidonoylethanolamine (anandamide, AEA), 2-AG, and the N-acylethanolamines (NAEs), N-palmitoylethanolamide (PEA) and N-oleoylethanolamide (OEA), which are structurally-related to AEA, in the brain, spinal cord and paw skin were measured using LC-MS/MS. Protein expression of MAGL in the paw skin was measured using Wes™. The effects of subcutaneous (s.c.) injection of 2-AG and JZL184 (a MAGL inhibitor) into the right hind paw of mice with paclitaxel-induced mechanical allodynia were assessed using the dynamic plantar aesthesiometer. The effects of pretreatment, s.c., into the right hind paw, with cannabinoid type 1 (CB1) receptor antagonist AM251 and CB2 receptor antagonist AM630 on the antiallodynic effects of 2-AG were also evaluated. RESULTS: The levels of 2-AG were reduced only in the paw skin of paclitaxel-treated mice, whilst the levels of AEA, PEA and OEA were not significantly altered. There was no change in the expression of MAGL in the paw skin. Administration of 2-AG and JZL184 produced antiallodynic effects against paclitaxel-induced mechanical allodynia in the injected right paw, but did not affect the uninjected left paw. The antiallodynic activity of 2-AG was antagonized by both AM251 and AM630. CONCLUSION: These results indicate that during paclitaxel-induced mechanical allodynia there is a deficiency of 2-AG in the periphery, but not in the CNS. Increasing 2-AG in the paw by local administration of 2-AG or a MAGL inhibitor, alleviates mechanical allodynia in a CB1 and CB2 receptor-dependent manner.

Early Enteral Administration of a Complex Lipid Emulsion Supplement Prevents Postnatal Deficits in Docosahexaenoic and Arachidonic Acids and Increases Tissue Accretion of Lipophilic Nutrients in Preterm Piglets.

BACKGROUND: Preterm delivery and current nutrition strategies result in deficiencies of critical long-chain fatty acids (FAs) and lipophilic nutrients, increasing the risk of preterm morbidities. We sought to determine the efficacy of preventing postnatal deficits in FAs and lipophilic nutrients using an enteral concentrated lipid supplement in preterm piglets. METHODS: Preterm piglets were fed a baseline diet devoid of arachidonic acid (AA) and docosahexaenoic acid (DHA) and randomized to enteral supplementation as follows: (1) Intralipid (IL), (2) complex lipid supplement 1 (CLS1) with an AA:DHA ratio of 0.25, or (3) CLS2 with an AA:DHA ratio of 1.2. On day 8, plasma and tissue levels of FAs and lipophilic nutrients were measured and ileum histology performed. RESULTS: Plasma DHA levels decreased in the IL group by day 2. In contrast, DHA increased by day 2 compared with birth levels in both CLS1 and CLS2 groups. The IL and CLS1 groups demonstrated a continued decline in AA levels during the 8-day protocol, whereas AA levels in the CLS2 group on day 8 were comparable to birth levels. Preserving AA levels in the CLS2 group was associated with greater ileal villus height and muscular layer thickness. Lipophilic nutrients were effectively absorbed in plasma and tissues. CONCLUSIONS: Enteral administration of CLS1 and CLS2 demonstrated similar increases in DHA levels compared with birth levels. Only CLS2 maintained AA birth levels. Providing a concentrated complex lipid emulsion with an AA:DHA ratio > 1 is important in preventing postnatal AA deficits.

Endocannabinoid Signaling from 2-Arachidonoylglycerol to CB1 Cannabinoid Receptor Facilitates Reward-based Learning of Motor Sequence.

The endocannabinoid system modulates synaptic transmission, controls neuronal excitability, and is involved in various brain functions including learning and memory. 2-arachidonoylglycerol, a major endocannabinoid produced by diacylglycerol lipase-α (DGLα), is released from postsynaptic neurons, retrogradely activates presynaptic CB1 cannabinoid receptors, and induces short-term or long-term synaptic plasticity. To examine whether and how the endocannabinoid system contributes to reward-based learning of a motor sequence, we subjected male CB1-knockout (KO) and DGLα-KO mice to three types of operant lever-press tasks. First, we trained mice to press one of three levers labeled A, B, and C for a food reward (one-lever task). Second, we trained mice to press the three levers in the order of A, B, and C (three-lever task). Third, the order of the levers was reversed to C, B, and A (reverse three-lever task). We found that CB1-KO mice and DGLα-KO mice exhibited essentially the same deficits in the operant lever-press tasks. In the one-lever task, both strains of knockout mice showed a slower rate of learning to press a lever for food. In the three-lever task, both strains of knockout mice showed a slower rate of learning of the motor sequence. In the reverse three-lever task, both strains of knockout mice needed more lever presses for reversal learning. These results suggest that the endocannabinoid system facilitates reward-based learning of a motor sequence by conferring the flexibility with which animals can switch between strategies.

Role of Striatal Direct Pathway 2-Arachidonoylglycerol Signaling in Sociability and Repetitive Behavior.

BACKGROUND: Endocannabinoid signaling plays an important role in regulating synaptic transmission in the striatum, a brain region implicated as a central node of dysfunction in autism spectrum disorder. Deficits in signaling mediated by the endocannabinoid 2-arachidonoylglycerol (2-AG) have been reported in mouse models of autism spectrum disorder, but a causal role for striatal 2-AG deficiency in phenotypes relevant to autism spectrum disorder has not been explored. METHODS: Using conditional knockout mice, we examined the electrophysiological, biochemical, and behavioral effects of 2-AG deficiency by deleting its primary synthetic enzyme, diacylglycerol lipase α (DGLα), from dopamine D1 receptor-expressing or adenosine A2a receptor-expressing medium spiny neurons (MSNs) to determine the role of 2-AG signaling in striatal direct or indirect pathways, respectively. We then used viral-mediated deletion of DGLα to study the effects of 2-AG deficiency in the ventral and dorsal striatum. RESULTS: Targeted deletion of DGLα from direct-pathway MSNs caused deficits in social interaction, excessive grooming, and decreased exploration of a novel environment. In contrast, deletion from indirect-pathway MSNs had no effect on any measure of behavior examined. Loss of 2-AG in direct-pathway MSNs also led to increased glutamatergic drive, which is consistent with a loss of retrograde feedback inhibition. Subregional DGLα deletion from the dorsal striatum produced deficits in social interaction, whereas deletion from the ventral striatum resulted in repetitive grooming. CONCLUSIONS: These data suggest a role for 2-AG deficiency in social deficits and repetitive behavior, and they demonstrate a key role for 2-AG in regulating striatal direct-pathway MSNs.

Unconventional endocannabinoid signaling governs sperm activation via the sex hormone progesterone.

Steroids regulate cell proliferation, tissue development, and cell signaling via two pathways: a nuclear receptor mechanism and genome-independent signaling. Sperm activation, egg maturation, and steroid-induced anesthesia are executed via the latter pathway, the key components of which remain unknown. Here, we present characterization of the human sperm progesterone receptor that is conveyed by the orphan enzyme α/ß hydrolase domain-containing protein 2 (ABHD2). We show that ABHD2 is highly expressed in spermatozoa, binds progesterone, and acts as a progesterone-dependent lipid hydrolase by depleting the endocannabinoid 2-arachidonoylglycerol (2AG) from plasma membrane. The 2AG inhibits the sperm calcium channel (CatSper), and its removal leads to calcium influx via CatSper and ensures sperm activation. This study reveals that progesterone-activated endocannabinoid depletion by ABHD2 is a general mechanism by which progesterone exerts its genome-independent action and primes sperm for fertilization.

Genetic variation in FADS genes is associated with maternal long-chain PUFA status but not with cognitive development of infants in a high fish-eating observational study.

Long-chain n-6 and n-3 PUFA (LC-PUFA), arachidonic acid (AA) (20:4n-6) and DHA (22:6n-3), are critical for optimal brain development. These fatty acids can be consumed directly from the diet, or synthesized endogenously from precursor PUFA by Δ-5 (encoded by FADS1) and Δ-6 desaturases (encoded by FADS2). The aim of this study was to determine the potential importance of maternal genetic variability in FADS1 and FADS2 genes to maternal LC-PUFA status and infant neurodevelopment in populations with high fish intakes. The Nutrition Cohorts 1 (NC1) and 2 (NC2) are longitudinal observational mother-child cohorts in the Republic of Seychelles. Maternal serum LC-PUFA was measured at 28 weeks gestation and genotyping for rs174537 (FADS1), rs174561 (FADS1), rs3834458 (FADS1-FADS2) and rs174575 (FADS2) was performed in both cohorts. The children completed the Bayley Scales of Infant Development II (BSID-II) at 30 months in NC1 and at 20 months in NC2. Complete data were available for 221 and 1310 mothers from NC1 and NC2 respectively. With increasing number of rs3834458 minor alleles, maternal concentrations of AA were significantly decreased (NC1 p=0.004; NC2 p<0.001) and precursor:product ratios for linoleic acid (LA) (18:2n-6)-to-AA (NC1 p<0.001; NC2 p<0.001) and α-linolenic acid (ALA) (18:3n-3)-to-DHA were increased (NC2 p=0.028). There were no significant associations between maternal FADS genotype and BSID-II scores in either cohort. A trend for improved PDI was found among infants born to mothers with the minor rs3834458 allele.In these high fish-eating cohorts, genetic variability in FADS genes was associated with maternal AA status measured in serum and a subtle association of the FADS genotype was found with neurodevelopment.

Central anandamide deficiency predicts stress-induced anxiety: behavioral reversal through endocannabinoid augmentation.

Stress is a major risk factor for the development of mood and anxiety disorders; elucidation of novel approaches to mitigate the deleterious effects of stress could have broad clinical applications. Pharmacological augmentation of central endogenous cannabinoid (eCB) signaling may be an effective therapeutic strategy to mitigate the adverse behavioral and physiological consequences of stress. Here we show that acute foot-shock stress induces a transient anxiety state measured 24 h later using the light-dark box assay and novelty-induced hypophagia test. Acute pharmacological inhibition of the anandamide-degrading enzyme, fatty acid amide hydrolase (FAAH), reverses the stress-induced anxiety state in a cannabinoid receptor-dependent manner. FAAH inhibition does not significantly affect anxiety-like behaviors in non-stressed mice. Moreover, whole brain anandamide levels are reduced 24 h after acute foot-shock stress and are negatively correlated with anxiety-like behavioral measures in the light-dark box test. These data indicate that central anandamide levels predict acute stress-induced anxiety, and that reversal of stress-induced anandamide deficiency is a key mechanism subserving the therapeutic effects of FAAH inhibition. These studies provide further support that eCB-augmentation is a viable pharmacological strategy for the treatment of stress-related neuropsychiatric disorders.

Anandamide deficiency and heightened neuropathic pain in aged mice.

Damaging of peripheral nerves may result in chronic neuropathic pain for which the likelihood is increased in the elderly. We assessed in mice if age-dependent alterations of endocannabinoids contributed to the heightened vulnerability to neuropathic pain at old age. We assessed nociception, endocannabinoids and the therapeutic efficacy of R-flurbiprofen in young and aged mice in the spared nerve injury model of neuropathic pain. R-flurbiprofen was used because it is able to reduce neuropathic pain in young mice in part by increasing anandamide. Aged mice developed stronger nociceptive hypersensitivity after sciatic nerve injury than young mice. This was associated with low anandamide levels in the dorsal root ganglia, spinal cord, thalamus and cortex, which further decreased after nerve injury. In aged mice, R-flurbiprofen had only weak antinociceptive efficacy and it failed to restore normal anandamide levels after nerve injury. In terms of the mechanisms, we found that fatty acid amide hydrolase (FAAH) which degrades anandamide, was upregulated after nerve injury at both ages, so that this upregulation likely did not account for the age-dependent differences. However, enzymes contributing to oxidative metabolism of anandamide, namely cyclooxygenase-1 and Cyp2D6, were increased in the brain of aged mice, possibly enhancing the oxidative breakdown of anandamide. This may overwhelm the capacity of R-flurbiprofen to restore anandamide homeostasis and may contribute to the heightened risk for neuropathic pain at old age.

Dietary long-chain polyunsaturated fatty acids upregulate expression of FADS3 transcripts.

The fatty acid desaturase (FADS) gene family at 11q12-13.1 includes FADS1 and FADS2, both known to mediate biosynthesis of omega-3 and omega-6 long-chain polyunsaturated fatty acids (LCPUFA). FADS3 is a putative desaturase due to its sequence similarity with FADS1 and FADS2, but its function is unknown. We have previously described 7 FADS3 alternative transcripts (AT) and 1 FADS2 AT conserved across multiple species. This study examined the effect of dietary LCPUFA levels on liver FADS gene expression in vivo and in vitro, evaluated by qRT-PCR. Fourteen baboon neonates were randomized to three diet groups for their first 12 weeks of life, C: Control, no LCPUFA, L: 0.33% docosahexaenoic acid (DHA)/0.67% arachidonic acid (ARA) (w/w); and L3: 1.00% DHA/0.67% ARA (w/w). Liver FADS1 and both FADS2 transcripts were downregulated by at least 50% in the L3 group compared to controls. In contrast, FADS3 AT were upregulated (L3 > C), with four transcripts significantly upregulated by 40% or more. However, there was no evidence for a shift in liver fatty acids to coincide with increased FADS3 expression. Significant upregulation of FADS3 AT was also observed in human liver-derived HepG2 cells after DHA or ARA treatment. The PPARγ antagonist GW9662 prevented FADS3 upregulation, while downregulation of FADS1 and FADS2 was unaffected. Thus, FADS3 AT were directly upregulated by LCPUFA by a PPARγ-dependent mechanism unrelated to regulation of other desaturases. This opposing pattern and mechanism of regulation suggests a dissimilar function for FADS3 AT compared to other FADS gene products.

NGF blocks polyunsaturated fatty acids biosynthesis in n-3 fatty acid-supplemented PC12 cells.

Regulation of polyunsaturated fatty acid (PUFA) biosynthesis in proliferating and NGF-differentiated PC12 pheochromocytoma cells deficient in n-3 docosahexaenoic acid (DHA 22:6n-3) was studied. A dose- and time-dependent increase in eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3) and DHA in phosphatidylethanolamine (PtdEtn) and phosphatidylserine (PtdSer) glycerophospholipids (GPL) via the elongation/desaturation pathway following alpha-linolenic acid (ALA, 18:3n-3) supplements was observed. That was accompanied by a marked reduction of eicosatrienoic acid (Mead acid 20:3n-9), an index of PUFA deficiency. EPA supplements were equally effective converted to 22:5n-3 and 22:6n-3. On the other hand, supplements of linoleic acid (LNA, 18:2n-6) were not effectively converted into higher n-6 PUFA intermediates nor did they impair elongation/desaturation of ALA. Co-supplements of DHA along with ALA did not interfere with 20:5n-3 biosynthesis but reduced further elongation to 22-hydrocarbon PUFA intermediates. A marked decrease in the newly synthesized 22:5n-3 and 22:6n-3 following ALA or EPA supplements was observed after nerve growth factor (NGF)-induced differentiation. NGF also inhibited the last step in 22:5n-6 formation from LNA. These results emphasize the importance of overcoming n-3 PUFA deficiency and raise the possibility that growth factor regulation of the last step in PUFA biosynthesis may constitute an important feature of neuronal phenotype acquisition.

Lipids including cholesteryl linoleate and cholesteryl arachidonate contribute to the inherent antibacterial activity of human nasal fluid.

Mucosal surfaces provide first-line defense against microbial invasion through their complex secretions. The antimicrobial activities of proteins in these secretions have been well delineated, but the contributions of lipids to mucosal defense have not been defined. We found that normal human nasal fluid contains all major lipid classes (in micrograms per milliliter), as well as lipoproteins and apolipoprotein A-I. The predominant less polar lipids were myristic, palmitic, palmitoleic, stearic, oleic, and linoleic acid, cholesterol, and cholesteryl palmitate, cholesteryl linoleate, and cholesteryl arachidonate. Normal human bronchioepithelial cell secretions exhibited a similar lipid composition. Removal of less-polar lipids significantly decreased the inherent antibacterial activity of nasal fluid against Pseudomonas aeruginosa, which was in part restored after replenishing the lipids. Furthermore, lipids extracted from nasal fluid exerted direct antibacterial activity in synergism with the antimicrobial human neutrophil peptide HNP-2 and liposomal formulations of cholesteryl linoleate and cholesteryl arachidonate were active against P. aeruginosa at physiological concentrations as found in nasal fluid and exerted inhibitory activity against other Gram-negative and Gram-positive bacteria. These data suggest that host-derived lipids contribute to mucosal defense. The emerging concept of host-derived antimicrobial lipids unveils novel roads to a better understanding of the immunology of infectious diseases.

The inadequacy of the essential fatty acid content of present preterm feeds.

UNLABELLED: Arachidonic (AA) and docosahexaenoic (DHA) acids are major components of endothelial, pulmonary and neuro-visual cell membranes. Preterm babies may be born with deficits of both AA and DHA. There is evidence that their endogenous anti-oxidant enzymes defence systems have only reached half the activity expected at term. Yet they are exposed to an oxygen tension greater than physiologically anticipated at this time, and the superoxide dismutase shows no evidence of significant catch-up. After birth, present enteral and parenteral feeds for the preterm baby result in a further drop of AA and DHA plasma proportions to a quarter or third of the intra-uterine expectation. At the same time, the proportion of linoleic acid (LA), the precursor for AA, rises in the plasma phosphoglycerides four-fold, thus denying the preterm infant the provision with which the placenta would have perfused the fetus to meet the very rapid demand for endothelial and neural growth. From the biochemistry it is predictable that this situation could lead to fragile cell membranes, leakage, rupture with peroxidation resulting in the formation of inflammatory and vasoconstrictive agents. CONCLUSION: The essential fatty acid content of current enteral and parenteral feeds for preterm infants is incorrectly formulated.

Reduced arachidonate in serum phospholipids and cholesteryl esters associated with vegetarian diets in humans.

Lipid fractions such as phospholipids (PLs), cholesteryl esters (CEs), and free fatty acids (FFAs) represent source pools for eicosanoid synthesis. To determine whether dietary habits affect the enrichment of 20:4n-6 in these precursor pools, we studied humans with partial or complete arachidonate restriction resulting from chronic avoidance of animal fat and tissue. Fasting serum was obtained from omnivorous control subjects (Omni, n = 100), semivegetarians (Semiveg, n = 16), and vegetarians (Veg, n = 25). PLs, CEs, FFAs, and triglyceride (TG) fatty acids were quantitated by thin-layer and gas chromatography. Serum 20:4n-6 was lower in the PL fraction in both Veg (p less than 0.01) and Semiveg groups (p less than 0.05) than in the Omni group and lower in the CE fraction in the Veg group (p less than 0.05). Serum 18:2n-6 did not differ between groups for any serum lipid fraction. 18:3n-3 was elevated in PLs and CEs of both Veg (p less than 0.05 and 0.01) and Semiveg groups (p less than 0.05 and 0.01) compared with the Omni group but did not result in differences in 20:5n-3 in PLs or CEs between diet groups. The lower concentration of 20:4n-6 in serum PLs and CEs of the Veg group indicates that dietary arachidonic acid enriches its circulating pool in humans; however, 20:5n-3 is not similarly responsive to dietary restriction.

Ether phospholipids in control and 20:4-depleted rat PMN: additional evidence for a 1-O-alkyl-2-20:4-sn-glycerol-3-phosphocholine specific phospholipase A2.

Earlier studies from out laboratory have shown that PAF and LTB4 biosynthesis are inhibited in rat PMN depleted of its 20:4 (JBC. '86, 261, 7592). To test whether these cells contain sufficient 1-O-alkyl-2-acyl-GPC to support PAF synthesis, phosphotidyl choline was isolated from these 20:4-depleted cells, fractionated into different subclasses and their fatty acid composition determined. These results were compared with those obtained with control PMN. Both control and 20:4-depleted PMN contained significantly large amounts of alkylacyl-GPC and diacyl-GPC. Small amounts (4%) of alkenyl-acyl-GPC were also present. The amount of 20:3 in 20:4-depleted cells was more or less equal to the amount of 20:4 in control cells. About 62% of PC-bond 20:4 in control PMN and about 56% of PC-bound 20:3 in the 20:4-depleted PMN was found associated with the alkylacyl species. These results show that both control and 20:4 depleted PMN have ample precursor substrates to support PAF biosynthesis and these substrates are enriched with 20:4 in control cells and with 20:3 in 20:4-depleted cells. These findings are consistant with the existance of a highly specific phospholipase A2 capable of distinguising 20:4 from 20:3 containing phospholipids.

Effects of arachidonate deficiency on endothelium-dependent vascular reactions.

1. The release of endothelium-derived relaxing factor (EDRF), which appears to be impaired in vessels chronically exposed to hypertension, may involve mobilization of arachidonate from phospholipids. In this study the effects of arachidonate deficiency on endothelium-dependent responses were examined in rat isolated aorta. 2. Weanling rats were fed an essential fatty acid-deficient (EFAD) diet for 8 weeks which reduced plasma and aortic phospholipid arachidonate content from 17 to 1.8% and from 21 to 8%, respectively. After this time the rats were killed and the reactivity of aortic rings was studied in organ baths. 3. In aortic rings from control rats the concentration-response curves for the contractile action of phenylephrine were shifted to the left 3.5-fold by removal of the endothelium, and the maximum was not altered. 4. In contrast, in EFAD rings with endothelium, the maximal vasoconstriction to phenylephrine was less than in control rings, and removal of the endothelium increased the maximum (from 1.9 +/- 0.2 to 3.2 +/- 0.1 g, P less than 0.05) and reduced the EC50 7-fold. 5. In EFAD rings precontracted with phenylephrine (0.3 mumol/l) the relaxations produced by the endothelium-dependent dilator acetylcholine were not significantly different from those produced in control rings. The dilator actions of sodium nitroprusside were also similar in EFAD and control rings. 6. Thus, endothelium-dependent dilatation in the aorta is not impaired by partial depletion of phospholipid arachidonate. However, contractile responses to alpha-adrenoceptor agonists are depressed by spontaneously released EDRF in rat aorta, so that the results suggest that depletion of phospholipid arachidonate either augments spontaneous release of EDRF, or impairs EDRF inactivating mechanisms.

Decreased pulmonary vascular responsiveness in rats raised on an essential fatty acid deficient diet.

Leukotriene C4 is produced during hypoxic pulmonary vasoconstriction and leukotriene inhibitors preferentially inhibit the hypoxic pressor response in rats. If lipoxygenase products are important in hypoxic vasoconstriction, then an animal deficient in arachidonic acid should have a blunted hypoxic pressor response. We investigated if vascular responsiveness was decreased in vascular rings and isolated perfused lungs from rats raised on an essential fatty acid deficient diet (EFAD) compared to rats raised on a normal diet. Rats raised on the EFAD diet had decreased esterified plasma arachidonic acid and increased 5-, 8-, 11-eicosatrienoic acid compared to rats raised on the normal diet (control). Compared to the time matched responses in control isolated perfused lungs the pressor responses to angiotensin II and alveolar hypoxia were blunted in lungs from the arachidonate deficient rats. This decreased pulmonary vascular responsiveness was not affected by the addition of indomethacin or arachidonic acid to the lung perfusate. Similarly, the pulmonary artery rings from arachidonate deficient rats demonstrated decreased reactivity to norepinephrine compared to rings from control rats. In contrast, the tension increases to norepinephrine were greater in aortic rings from the arachidonate deficient rats compared to control. Stimulated lung tissue from the arachidonate deficient animals produced less slow reacting substance and platelet activating factor like material but the same amount of 6-keto-PGF1 alpha and TXB2 compared to control lungs. Thus there is an association between altered vascular responsiveness and impairment of stimulated production of slow reacting substance and platelet activating factor like material in rats raised on an EFAD diet.

Hyperglycemia-induced teratogenesis is mediated by a functional deficiency of arachidonic acid.

Congenital malformations now represent the largest single cause of mortality in the infant of the diabetic mother. The mechanism by which diabetes exerts its teratogenic effects is not known. This study evaluated whether arachidonic acid might be involved, a possibility raised by the role of arachidonic acid in palatal elevation and fusion, processes analogous to neural tube folding and fusion. This hypothesis was tested in two animal models of diabetic embryopathy, the in vivo pregnant diabetic rat and the in vitro hyperglycemic mouse embryo culture. The subcutaneous injection of arachidonic acid (200-400 mg/kg per day) into pregnant diabetic rats during the period of organ differentiation (days 6-12) did not alter the maternal glucose concentration, the maternal weight gain, or the weight of the embryos. However, the incidence of neural tube fusion defects was reduced from 11% to 3.8% (P less than 0.005), the frequency of cleft palate was reduced from 11% to 4% (P less than 0.005), and the incidence of micrognathia was reduced from 7% to 0.8% (P less than 0.001). The addition of arachidonic acid to B10.A mouse embryos in culture also resulted in a reversal of hyperglycemia-induced teratogenesis. The teratogenic effect of D-glucose (8 mg/ml) in the medium resulted in normal neural tube fusion in only 32% of the embryos (P less than 0.006 when compared to controls). Arachidonic acid supplementation (1 or 10 micrograms/ml) produced a rate of neural tube fusion (67%) that was not significantly different from that observed in controls. The evidence presented indicates that arachidonic acid supplementation exerts a significant protective effect against the teratogenic action of hyperglycemia in both in vivo (rat) and in vitro (mouse) animal models. These data therefore suggest that the mechanism mediating the teratogenic effect of an increased glucose concentration involves a functional deficiency of arachidonic acid at a critical stage of organogenesis.

[Effect of acute stress on the fatty acid composition of lipids of adrenal and heart mitochondria in rabbits]. / Vliianie ostrogo stressa na zhirno-kislotnyi sostav lipidov mitokhondrii nadpochechnikov i serdtsa krolika.

A comparative study of changes in the fatty acid composition of rabbit heart and adrenal mitochondria was carried out after acute (1h) immobilization stress. In heart mitochondria the stress induced a decrease in the content of capric, lauric, myristic and pentadecanic acids. A statistically significant reduction of the amount of heptadecanoic, linoleic, arachidonic acids and an increase in the level of palmitic acid was noted in adrenal mitochondria. The acute stress resulted in differently directed shifts in the saturation of fatty acids. An elevation of the sum of unsaturated fatty acids was observed in the heart, and a decrease was detected in the adrenal glands. The above shifts in the fatty acid composition of adrenal and heart mitochondria provide evidence for different directions of lipid metabolism in these organs following stress.

[Characteristics of early disorders of fatty-acid composition of kidney lipids in spontaneous (hereditary) arterial hypertension]. / Kharakteristika rannikh narushenii zhirnokislotnogo sostava lipidov pochek pri spontannoi (nasledstvenno obuslovlennoi) arterial'noi gipertenzii.

Fatty acid composition of kidney lipids from spontaneously hypertensive Okamoto-Aoki rats (SHR) and normotensive Wistar rats (NR) was investigated two days after birth by gas-liquid chromatography. In SHR kidney phospholipids, as compared to the respective NR values, the content of arachidonic acid (20:4n6) was decreased and the levels of oleic (18:1n9) and docosahexaenoic (22:6n3) acids were increased; in kidney triglycerides, the content of eicosatrionoic acid (20:3n9) and all fatty acids of the linoleic acid series was decreased, except the content of a polyunsaturated long-chain product of linoleic acid metabolism, docosapentaenoic acid (22:5n6) that was increased. These changes may have developed prenatally as a result of genetic peculiarities of SHR.

Abnormal polyunsaturated fatty acid patterns of serum lipids in alcoholism and cirrhosis: arachidonic acid deficiency in cirrhosis.

Patterns of polyunsaturated fatty acids of serum phospholipids were measured for groups of alcoholics without cirrhosis, alcoholics with cirrhosis, cirrhotics without alcoholism, and a control population. Alcoholics without cirrhosis showed increased polyunsaturated fatty acids derived from linoleic and linolenic acids, but in cirrhotics these products were decreased. Alcoholism accentuated the abnormal polyunsaturated fatty acid pattern of cirrhosis. In alcohol abuse without cirrhosis, the level of 20:3 omega 9 (20 acyl carbon atoms:3 double bonds, omega, 9 carbon atoms beyond last double bond) was significantly increased, despite adequate levels of linoleic and arachidonic acids. Liver involvement appears necessary for development of deficiencies of polyunsaturated fatty acids in serum phospholipids, of which arachidonic acid deficiency is of the largest magnitude.