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It was established that in neurodegeneration models in the human neuron-like cell line SH-SY5Y, amide derivatives of arachidonic and docosahexaenoic acids were inactive in experiments with MPP+ and CoCl2 but protected from H2O2. The protective activity of neurolipins decreased in the series DHA-DA > AA-SER >= AA-GLY > AA-GABA >= AA-EA and was manifested starting from a concentration of 0.5 nM.

We have studied the effect of a GABA conjugate with arachidonic acid (AA) on the morphological state of rat brain tissues after left median cerebral artery occlusion. The results showed that a 6- and 12-day course administration of the GABA - AA conjugate at dose of 2 mg/kg (i.p.) in rats with this model of local permanent brain ischemia led to significant recovery processes in brain tissues. The tissue morphology pattern in the group of animals treated with the GABSA - AA conjugate for 12 days was almost identical to that in intact tissues.

The protocol for the quantitative analysis of nitric oxide as nitrite-ion suitable for determination of its production by a mammalian cell culture was developed. The optimal results were obtained using microvolume-adjusted Griess method after the preliminary reduction of NO3- to NO2- with non-activated cadmium. The protocol was verified on a rat glioma C6 cell culture. The developed method may be used for the nitric oxide determination in 96-well and 48-well microplates; the detection limit is 2.1 ± 0.1 μM for NO2- and 2.9 ± 0.1 μM for NO3-.

In experiments on rats, measurements of the local blood flow in the cortex of cerebrum with the aid of a laser Doppler flow meter showed that docosahexaenoic acid (DHA) enhanced the local cerebral circulation in animals with global transient cerebral ischemia, while not influencing that in intact animals. This vasodilatory effect of DHA in ischemized rats is blocked by bicuculline (specific GABA(A) receptor blocker), which is indicative of a GABA-ergic mechanisms of the vascular tone regulation. The results of radioligand binding assay in vitro showed the possibility of direct DHA interaction with cerebrovascular GABA(A) receptors.

The influence two original derivatives of a therapeutically important peptide, bearing arachidonic acid residue with semax and proglyprol, upon platelet aggregation have been studied in vitro. It is established that both derivatives, in contrast to the parent peptide, possess moderate anti-aggregant properties and produce a dose-dependent decrease in the interplatelet interaction induced by ADP, epinephrine, and arachidonic acid within the concentration range of 0.018 - 1.8 mM. This activity was more pronounced for arachidonoylsemax in comparison with arachidonoylproglyprol.

Experiments have shown that GABA conjugate with prostaglandin E2 enhances cerebral blood flow in rats after global transient ischemia, while not affecting the cerebral hemoperfusion in intact animals. It is established that cerebrovascular activity of the GABA conjugate with prostaglandin E2 under conditions of cerebral ischemia is based on GABAergic mechanisms of vascular tone regulation, since it is removed by GABA(A)-receptor blocker bicuculline. At the same time, cerebral blood flow of intact rats and rats after global transient ischemia of brain is equally enhanced by prostaglandin E2 alone. This effect is not neutralized by bicuculline.

A GABA conjugate with docosahexaenoyl dophamine (DHED) enhanced local cerebral blood flow in rats under conditions of global transient cerebral ischemia, experimental myocardial infarction, and combined vascular pathology of brain and heart. At the same time, the GABA-DHED conjugate did not influence brain hemoperfusion in intact animals. The cerebrovascular effect of this conjugate is determined by its direct action on the vascular tone, since no changes in blood pressure have been observed. Under conditions of the combined vascular pathology of brain and heart, the cerebrovascular effect of GABA-DHED conjugate is inhibited by bicuculline, which is evidence for the involvement of GABAergic mechanisms in the drug action upon cerebrovascular tone.

Experiments on rats showed that, under conditions of global transient ischemia, a conjugate of GABA with arachidonic acid enhances the local cerebral blood flow due to a decrease in the vascular tone. In intact rats, the examined neurolipin did not show unidirectional changes in the cerebral perfusion. Under conditions of experimental myocardial infarction and combined vascular pathology of brain and heart, the GABA conjugate with arachidonic acid increased the blood flow in the parietal region of brain cortex in most experiments, while decreasing the level of blood pressure.

A method for isolation of interferon beta1b (Serl7) from inclusion bodies, comprising the steps of solution and reduction of protein from the inclusion bodies, refolding, chromatography on DEAE-Sepharose, chromatography on SP-Sepharose, concentrating, desalting and addition of stabilizers. The solution of reduced protein was diluted with pH 8.0 buffer of 50 mM Tris-HCl, 25 microM CuCl2 and 0.5% Twin 20 for refolding. We used gradient of pH (from 9.3 upto 11.3) for elution of interferon-beta from cation-exchange column. We concentrated of eluate and then desalted on the Sephadex G-50 column with 1 mM NaOH. Then the protein solution was neutralized with mannitol and Na-phosphate. Obtained preparation of interferon-beta was pure by gel-electrophoresis and by HPLC analysis, and had practically indentical level of antiproliferative activity with well-known preparation of Betaferone. Thus we show the possibility of isolation and obtaining of pure and active interferone-beta by ion-exchange chromatography in the presence of non-ion detergent Twin 20. We believe this method for interferon betalb preparation is perspective for scaling and using in the develop of industrial technology for production of this preparation.

The effect of derivatives of arachidonic and docosahexaenoic acids on AMPA receptors in Purkinje cells from the rat cerebellum was studied using the patch-clamp electrophysiological method. It was shown that derivatives of arachidonic acid-arachidonoyl dopamine and docosahexaenoic acid-docosahexaenoyl dopamine and ester of docosahexaenoic acid with ethylene glycol in nanomolar concentrations effectively potentiated the ionic currents caused by activation of AMPA receptors of kainic acid. Ester of docosahexaenoic acid with nitroethylene glycol blocked AMPA receptors, and anandamide (ethanolamide of arachidonic acid) was not effective. A behavioral test showed that docosahexaenoyl dopamine in doses of 0.1-20 mg/kg had no effect on the learning and memory abilities of the animals tested.

Glycerol esters 1,3-dinitrates of the cyclooxygenase metabolites of natural prostaglandin 2-arachidonoylglycerol, an endogenous ligand of cannabinoid receptors, were synthesized for the first time. Four methods of synthesis of these esters were developed via the activation of a carboxyl group and their chemical and pharmacological properties were investigated. The esters exhibit a more selective pharmacological spectrum of activities in comparison with the corresponding natural prostaglandins: some types of myotropic activity were enhanced, while others were loosened. 1,3-dinitroglycerol esters act as vasodilators, whereas the majority of natural prostaglandins act as vasoconstrictors. The observed changes result from the introduction of an NO-releasing fragment into prostaglandin molecule.

The effects of GABA - docosahexaenoyldopamine (DHED) conjugate on the cerebral haemodynamics and thrombocyte aggregation were evaluated and compared to these of docosahexaenoyldopamine alone. The GABA - DHED conjugate was shown to significantly enhance the cerebral circulation in rats with a model of global transient cerebral ischemia, as compared to the intact animals. Administered alone, DHED increased the blood supply of both intact and ischemic brains to an equal extent. The GABA-DHED conjugate demonstrated the antiaggregative activity, but the effect was less expressed than that of DHED alone.

In the terrestrial snail a direct monosynaptic glutamatergic connection between the primary sensory neuron and a premotor interneuron involved in withdrawal behaviour can be functionally identified using electrophysiological techniques. We investigated the involvement of cannabinoids in regulation of this synaptic contact. The results demonstrate that the specific binding sites for agonists to mammalian type 1 cannabinoid receptors (CB1Rs) exist in the snail's nervous system. Application of a synthetic cannabinoid agonist anandamide selectively changed the efficacy of synaptic contacts between the identified neurons. A decrease in the long-term synaptic facilitation of the synaptic contact elicited by high-frequency nerve tetanization in the presence of cannabinoid agonist anandamide was observed, suggesting a possible role of endocannabinoids in regulation of plasticity at this synaptic site. The selective antagonist of CB1Rs [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide] AM251 bath application was changing the efficacy of the synaptic contact only when the postsynaptic neuron had been intracellularly activated before its application. This observation implies an involvement of endocannabinoids in plasticity phenomena induced by activity in the postsynaptic target. Additional support of endocannabinoid involvement in synaptic function at this site was given by experiments in which AM251 blocked the short-term suppression of synaptic excitation evoked by low-frequency nerve tetanization, a phenomenon qualitatively similar to cannabinoid-dependent synaptically evoked suppression of excitation demonstrated in the mammalian nervous system. The results of the present study suggest an involvement of cannabinoids in the regulation of synaptic efficacy. Further, anandamide could be a candidate for an endogenous neuromessenger involved in plasticity processes.

N-Arachidonoyl (AA) derivatives of amino acids (glycine, phenylalanine, proline, valine, gamma-amino butyric acid (GABA), dihydroxyphenylalanine, tyrosine, tryptophan, and alanine) and peptides (Semax, MEHFPGP, and PGP) were synthesized in order to study the biological properties of acylamino acids. The mass spectra of all the compounds at atmospheric pressure electrospray ionization display the most intense peaks of protonated molecular ions; the detection limits for these compounds are 10 fmol per sample. AA-Gly showed the highest inhibitory activity toward fatty acid amide hydrolase from rat brain (IC50 6.5 microM) among all the acylamino acids studied. AA-Phe, AA-Tyr, and AA-GABA exhibited a weak but detectable inhibitory effect (IC50 55, 60, and 50 microM, respectively). The acylated amino acids themselves, except for AA-Gly, were stable to the hydrolysis by this enzyme. All the arachidonoylamino acids inhibited cabbage phospholipase D to various degrees; AA-GABA and AA-Phe proved to be the most active (IC50 20 and 27 microM, respectively). Attempts to detect the biosynthesis of AA-Tyr in homogenates of rat liver and nerve tissue showed no formation in vitro of either this acylamino acid or AA-dopamine and AA-Phe, the products of its metabolism. The highest contents of these metabolites were detected in liver homogenate and in the brain homogenate, respectively. Acylamino acids exert no cytotoxic effect toward the glioma C6 cells. It was shown that N-acylation of Semax with arachidonic acid results in enhancement of its hydrolytic stability and increases its affinity for the sites of specific binding in rat cerebellum membranes. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol. 32, no. 3; see also http://www.maik.ru.

Arachidonoyl dopamine and haloperidol, both separately and in different combinations, inhibit regeneration of the gastral and basal regions of hydra. In addition, both substances induce stable anomalies of morphogenesis in the form of outgrowths and additional tentacles in gastral regenerates. In the presence of both substances at different combinations, anomalies either do not appear altogether, or exist for a short time, thus suggesting the normalization of morphogenesis. Possible mechanisms underlying the effects of these substances are discussed.

A series of six new synthetic dinitroglycerol esters of fatty acids on the human platelet aggregation was studied in vitro. Inclusion of the dinitroglycerol moiety into the molecule of arachidonic acid deprived this acid from pro-aggregant activity. All six compounds produced moderate (dose-dependent) inhibition of the platelet aggregation process induced by arachidonic acid (1 x 10(-3) M). Platelet aggregation was most significantly affected by dinitroglycerol esters of arachidonic and docosahexaenoic acids. This is probably explained by the influence of these esters on the oxidative metabolism of arachidonic acid to eicosanoids playing the role of proaggregants. In the presence of vessel wall (rat aorta fragments), dinitroglycerol esters of arachidonic and docosahexaenoic acids incubated with platelets (5 min, 37 degrees C) significantly reduced their aggregation induced by arachidonic acid (1 x 10(-3) M) or docosahexaenoic acid (1 x 10(-5) M) under the conditions of endothelial cyclooxygenase suppressed by acetylsalicylic acid (10 mg/ml). The pronounced antiaggregant effect of the synthetic dinitroglycerol esters studied is probably related to their ability to act as NO donors suppressing the activity of thrombocytes (provided that the NO production activity is present in the system).

A series of original dopaminamides of polyunsaturated fatty acids were synthesized and characterized with respect to antiaggregant and cerebrovascular stimulant properties. It was established that dopaminamides of linolic, dimethyllinolic, docosapentaenoic, docosahexaenoic (DHEA) and stearidonic (C18:4 and C18:3) acids decrease ADP and arachidonic acid (AA) induced human thrombocyte aggregation in vitro. The most pronounced antiaggregant effect was observed for DHEA dopaminamide: in a dose of 10 mg/kg, this agent produced a significant decrease in the AA induced thrombocyte aggregation. DHEA per se in the same dose increases the activated partial thromboplastin time (APTT), while not affecting the prothrombin time. The synthesized dopaminamides of arachidonic, eicosapentaenoic, and docosahexaenoic acids stimulate local circulation in the cerebral cortex. The most pronounced cerebrovascular effect was also produced by DHEA dopaminamide.

Choline esters of polyenoic fatty acids block cleavage divisions of sea urchins and evoke the formation of one-cell multinuclear embryos. If the fatty acids AA-Ch or DHA-Ch are added at the mid or late blastula stage, many cells are extruded, forming extra-embryonic cell clusters near the animal pole of embryos or larvae. Both effects are prevented by dimethylaminoethyl esters of polyenoic fatty acids (AA-DMAE or DHA-DMAE) or their 5-hydroxytryptamides. Nicotinic acetylcholine receptor antagonists, imechine, d-tubocurarine or QX-222 provide partial protection against AA-Ch or DHA-Ch. The organophosphate pesticide, chlorpyrifos, or a combination of (-)-nicotine + phorbol 12-myristate 13-acetate, also evoke the mass extrusion of transformed embryonic cells at the animal pole of larvae. These effects are similarly antagonized by AA-DMAE, DHA-DMAE, or fatty acids 5-hydroxytryptamides. Taking together, these results suggest that AA-Ch and DHA-Ch act on sea urchin embryos and larvae as agonists of acetylcholine receptors, whereas AA-DMAE and DHA-DMAE act as antagonists. The ability of fatty acids 5-hydroxytryptamides to prevent the effects of AA-Ch or DHA-Ch may be due to restoration of the normal dynamic balance of cholinergic and serotonergic signaling during cleavage divisions and gastrulation.

Three main effects of the amides on embryos of opistobranch molluscs, sea urchins and starfish, were revealed. First, a rather independent and clear protective action of 5-HYDROXYTRYPTAMIDES AND 3-HYDROXYTYRAMIDES against cytostatic antagonists of serotonin and dopamine, resp. Second, prevention of developmental abnormalities induced by protein kinase C activators both by hydroxytryptamides and hydroxytyramides. Third, the cytostatic effect of 3-HYDROXYTRIPTAMIDES eliminated or prevented by 5-HYDROXYTRYPTAMIDES. These effects quantitatively depended on the structure of their fatty acids part. Some functionally active regulatory substances similar to 5-HYDROXYTRYPTAMIDES AND 3-HYDROXYTYRAMIDES may exist in the early embryos.

The interaction of organic nitrates (nitroethyleneglycol, dinitroglycerol, and their esters with arachidonic acid) with oxyhemoglobin and methemoglobin has been studied. Addition of nitroethyleneglycol and dinitroglycerol to oxyhemoglobin is accompanied by a modest but significant increase in oxidation rate of the heme protein to the high-spin ferri-form--methemoglobin. Arachidonoylglycerol dinitrate exerts a similar but more pronounced effect on hemoglobin: a molar excess of this dinitrate induces the transformation of a significant portion of oxyhemoglobin to methemoglobin, whereas arachidonoylnitroethyleneglycol is inactive. Arachidonoylglycerol dinitrate also induces changes in the spectral characteristics of methemoglobin; this may be due to disintegration of the methemoglobin with the loss of heme. The data demonstrate that some organic nitrates can interact with hemoglobin; this should be taken into account when using the oxyhemoglobin technique for measuring nitric oxide generation from these compounds.

Ritanserin and inmecarb hydrochloride, antagonists of serotonin, act cytostatically and teratogenically on early embryos of Tritonia diomedea, a nudibranch mollusk. On the basis of a pharmacological analysis and the type of developmental abnormalities observed, this action appears to be due to disturbances in the functional activity of endogenous serotonin and is associated with damage of to the cytoskeleton. The effects of ritanserin and inmecarb are prevented or attenuated by lipophilic serotonin analogs (serotoninamides of polyenoic fatty acids), as well as by polypeptides isolated from neurons Pd5 and Pd6 of the pedal ganglia of the adult Tritonia. In late embryos (stage of veligers), serotonin and to a lesser extent its lipophilic analogs strongly increase embryonic motility. This effect of serotonin is potentiated by some neuropeptides and inhibited by others. These results provide evidence for functional interaction between serotonin and neuropeptides in the control processes of embryogenesis.

We studied the effects of three inhibitors of catecholamine synthesis on the development of sea urchins Sphaerechinus granularis and Paracentrotus lividus. These drugs affected the early embryogenesis, which was expressed in inhibition of the cleavage divisions, appearance of abnormal embryos, and developmental arrest. The addition of arachidonic acid amide and dopamine to the incubation medium weakened the effects of the inhibitors. Spiperone induced developmental defects in preimplantation mouse embryos and sea urchin embryos. Arachidonic acid amide with dopamine exerted a protective effect against spiperone when introduced to sea urchin embryos at the blastula or late gastrula stages, rather than after fertilization. In murine embryos, this amide induced developmental defects and arrest itself and its effect was reversible. Possible mechanisms underlying the effects of these drugs are discussed.

We reported previously that synthetic amides of polyunsaturated fatty acids with bioactive amines can result in substances that interact with proteins of the endogenous cannabinoid system (ECS). Here we synthesized a series of N-acyl-dopamines (NADAs) and studied their effects on the anandamide membrane transporter, the anandamide amidohydrolase (fatty acid amide hydrolase, FAAH) and the two cannabinoid receptor subtypes, CB(1) and CB(2). NADAs competitively inhibited FAAH from N18TG2 cells (IC(50)=19-100 microM), as well as the binding of the selective CB(1) receptor ligand, [(3)H]SR141716A, to rat brain membranes (K(i)=250-3900 nM). The arachidonoyl (20:4 omega 6), eicosapentaenoyl (20:5 omega 3), docosapentaenoyl (22:5 omega 3), alpha-linolenoyl (18:3 omega 3) and pinolenoyl (5c,9c,12c 18:3 omega 6) homologues were also found to inhibit the anandamide membrane transporter in RBL-2H3 basophilic leukaemia and C6 glioma cells (IC(50)=17.5-33 microM). NADAs did not inhibit the binding of the CB(1)/CB(2) receptor ligand, [(3)H]WIN55,212-2, to rat spleen membranes (K(i)>10 microM). N-arachidonyl-dopamine (AA-DA) exhibited 40-fold selectivity for CB(1) (K(i)=250 nM) over CB(2) receptors, and N-docosapentaenoyl-dopamine exhibited 4-fold selectivity for the anandamide transporter over FAAH. AA-DA (0.1-10 microM) did not displace D1 and D2 dopamine-receptor high-affinity ligands from rat brain membranes, thus suggesting that this compound has little affinity for these receptors. AA-DA was more potent and efficacious than anandamide as a CB(1) agonist, as assessed by measuring the stimulatory effect on intracellular Ca(2+) mobilization in undifferentiated N18TG2 neuroblastoma cells. This effect of AA-DA was counteracted by the CB(1) antagonist SR141716A. AA-DA behaved as a CB(1) agonist in vivo by inducing hypothermia, hypo-locomotion, catalepsy and analgesia in mice (1-10 mg/kg). Finally, AA-DA potently inhibited (IC(50)=0.25 microM) the proliferation of human breast MCF-7 cancer cells, thus behaving like other CB(1) agonists. Also this effect was counteracted by SR141716A but not by the D2 antagonist haloperidol. We conclude that NADAs, and AA-DA in particular, may be novel and useful probes for the study of the ECS.

Most biological functions of unsaturated fatty acids are due to their ability to act as second messengers or modulators of activities of functionally important proteins; these functions are not related to oxidative metabolism of unsaturated fatty acids. These acids regulate the activity of phospholipases, ion channels, ATPases, G-proteins, and protein kinases; they also modulate the phosphoinositide and sphingomyelin cycles, the transfer of hormonal information, and gene transcription. The great diversity of effects of unsaturated fatty acids and their presence at the earliest stages of evolution suggest for these bioregulators a system-forming role in the living body.

Amides of fatty acids are lipid bioregulators formed from long chain saturated and unsaturated fatty acids via amidation by the corresponding amines. Ethanolamides of fatty acids are the most well-studied species of this group; an alternative pathway for their biosynthesis includes hydrolysis of N-acylated phosphatidylethanolamines by phospholipase D. Ethanolamides of fatty acids bind to the cannabinoid receptors of the central nervous system (CB1) or peripheral tissues (CB2) and can be considered as endogenous ligands of these receptors. Their pharmacological properties are similar to that of cannabimimetics. Simple amides of fatty acids are also endogenous bioregulators acting like sleep-inducing (oleamide) or angiogenic factors (erucamide). A new group of bioregulators comprise the amides of fatty acids and biologically active amines (vanillinamine, dopamine, and serotonin).

Dopamine, histamine, serotonin, and serotonin analogs were acylated with arachidonic and eicosapentaenoic acids, and the reaction products were named as artificially functionalized fatty acids (AFFA). The amides of arachidonic acid with serotonin, dopamine, and histamine were found to inhibit human platelet aggregation induced by ADP, arachidonic acid and adrenaline. Amides of arachidonic and eicosapentaeonic acids with serotonin and dopamine protect sea urchin early embryos against cytotoxic action of serotonin and histamine antagonists. These effects are not connected with the possible hydrolytic cleavage of AFFA to their constituent polyenoic fatty acids and amines. Arachidonic acid dopaminamide was shown to be a substrate of soybean 15-lipoxygenase, whereas the arachidonic acid amides with serotonin and its derivatives were resistant to this enzyme. Moreover, arachidonic acid serotoninamide turned out to be an irreversible lipoxygenase inhibitor. Considerable amount of hydroxyl radicals (fluorescent assay) were found for the first time to accompany lipoxygenase oxidation of linoleic acid; arachidonic acid serotoninamide blocked this process completely. Therefore, it was concluded that AFFA possess specific biological activity and can be considered as a novel group of lipid bioregulators.

(+/-)-15-Fluoro-11,15-dideoxyprostaglandin E1 and its methyl and ethyl esters were synthesized. Dehydroxyfluorination reaction (+/-)-11-deoxyprostaglandin E1 esters with various reagents based on SF4 was studied. Along with the target 15-fluorides (mixtures of alpha- and beta-epimers), products of allylic shift and dehydration in a ratio dependent on the fluorination agent were shown to be formed. With a morpholinotrifluorosulfuran-tris(morpholine)sulfonium trimethyldifluorosilicate mixture, the maximal excess (70%) of one of the 15-fluoro epimers was achieved. Possible mechanisms of dehydroxyfluorination of (+/-)-11-deoxyprostaglandin E1 esters with dialkylaminoflluorosulfurans were proposed. Methyl esters of 15-alpha-fluoro- and 15-beta-fluoro-11,15-dideoxyprostaglandin E1 exhibited moderate antiaggregation activity in rabbit platelet tests.

The main arachidonic acid metabolites released into the medium by mouse splenocytes have been identified on the basis of chromatographic and spectral studies as well as by mass spectrometry of the derivatives. In the absence or presence of exogenous arachidonic acid mouse splenocytes produce mainly 12-hydroxy-5,8,10,14-eicosatetraenoic and 12,20-dihydroxy-5,8,10,14-eicosatetraenoic acids. Both products are constantly released by intact cells into surrounding media without stimulation by exogenous substrate or other modulators. For the first time it is shown that exogenously added ganglioside GM3 lactone as well as ganglioside GM3 itself can influence the arachidonic acid metabolism in splenocytes.

The effects of fluorodeoxy prostanoids on platelet aggregability were studied. It was shown that introduction of fluorine into positions 9, 11 or 15 of prostaglandin F2 alpha led to enhanced proaggregation activity. The most active compound among fluorodeoxy analogs was 15-fluoro derivative; bisfluoro analog was moderately active, and 11-fluoro compound had the least activity. In the group of fluorodeoxy prostaglandins E2, a contrary effect was registered. Thus, the most active compound was 1-fluoride and the least, 15-fluoride. The incorporation of fluorine into position 15 of prostacyclin led to insignificantly lower antiaggregatory activity just as this modification of 6-keto-prostaglandin F1 alpha was accompanied by a dramatic increase in its ability to inhibit platelet aggregation.

A practical synthesis of cis-monoepoxides from free arachidonic 20:4 (n-6), eicosapentaenoic 20:5 (n-3) and docosahexaenoic 22:6 (n-3) acids, their cytochrome P-450 epoxygenase metabolites, is described. The free polyunsaturated fatty acids (PUFA) were oxidized each by 1.25 eq. m-chloroperbenzoic acid in ethanol to give a mixture of PUFAs' mono-epoxy derivatives (45%) which was separated by HPLC and the individual isomers were characterised by mass spectrometry. All regioisomers of the free PUFAs' cis-monoepoxides were thus obtained.

Using reverse phase high performance chromatography with UV-detection, the arachidonic acid cascade in human peripheral blood lymphocytes (PBL) was studied. It was found that PBL oxidized arachidonic acid via the lipoxygenase pathway, 12-hydroxyeicosatetraenoic acid (12-HETE) being the major metabolite of endogenous arachidonic acid. Exogenous arachidonic acid added to human PBL suspensions increased 12-HETE synthesis 5-7 times. In another experimental series the effects of gangliosides (GD3, GM1 and GM3) on lipoxygenase-catalyzed oxidation of arachidonic acid in human lymphocytes were investigated. All the gangliosides tested stimulated PBL to secrete 12-HETE both from endogenous and exogenous arachidonic acid. In most cases the stimulating effect of GD3 was much more apparent that those of GM1 and GM3.

The hydrolysis by phospholipase A2 of the following synthetic phospholipids has been investigated: 2-oleoyl-1-palmitoyl-3-sn-glycerophosphorylcholine, 4-stearoyloxybutylphosphorylcholine, 4-oleoyloxy-5-palmitoyloxypentylphosphorylcholine, and 2-(hexadecyloxycarbonyl)ethylphosphorylcholine.

E- and Z-isomers of 15-fluoro-13,14-dehydrocarbacyclin were synthesized starting from 2,3-epoxy-bicyclo[3.3.0]octan-6-one ethylene ketal with the use of 3-fluoro-1-octynydlithium.BF3 reagent and Wittig condensation. The ratio of isomeric the oxirane opening reaction and Wittig olefinization products was in each case 1:1. The synthesized compounds were identified by 13C NMR spectra. The antiaggregating activity of 5E-isomer was 2 x 10(-4) of the activity of corresponding 15-hydroxy compound, 5Z-isomer being even less active.

Prostaglandins E, F, I2 and thromboxane B2 have been studied by secondary ion mass spectrometry. It is shown that the method is suitable for direct identification of these compounds either as free acids or as their sodium salts. The spectra of the former reveal their structural features, while with the latter information on the molecular weight can be obtained. The limit of detection (about 1 microgram) allows the analysis of prostaglandin solutions of 1 microgram/microliter concentrations used in pharmacological tests.