RESUMO
Prostacyclin (PGI2), the main prostanoid in most vascular tissues regulates haemostasis and vascular tone, as well as the proliferation of smooth muscle cells. We have previously reported that lymphocyte contact with endothelium enhances endothelial cell PGI2 output. Here, we demonstrate the specificity of lymphocytes for switching on this response. Co-incubation of human umbilical vein endothelial cells (HUVEC) in serum-free medium with allogeneic peripheral blood lymphocytes (PBL), at a PBL:HUVEC ratio of 9:1, enhanced the basal (HUVEC alone) PGI2 output by 2.5-fold under static conditions, and was not altered in conditions mimicking shear stress. It occurred without previous activation of either cell type and was dependent upon specific interactions with PBL. Indeed, the PGI2 output induced by the co-incubation with resting neutrophils, non-activated platelets or latex beads was significantly lower than that induced by PBL. Blocking endothelial cell adhesion molecules (ECAM) E-selectin, vascular cell adhesion molecule-1 (VCAM-1) or intracellular adhesion molecule-1(ICAM-1) did not modify the PBL-induced PGI2 output, although 51Cr-labelled PBL adhesion was significantly decreased with anti-ICAM-1 antibody. Changes in the fatty acid composition of membrane phospholipids induced by incubation with eicosapentaenoic (EPA) or docosahexaenoic acids (DHA) resulted in diminished basal PGI2 output and adhesion of 51Cr-labelled PBL, whereas the PBL-stimulated PGI2 output was not modified. This specific cell-cell interaction represents a new stimulus for PGI2 synthesis that does not primarily involve the ECAM pathway, is independent of cell membrane fatty acid composition and shear stress. This switch-on for PGI2 synthesis, which is induced by lymphocytes, might serve as a protection against atherogenesis.
Assuntos
Arteriosclerose/metabolismo , Endotélio Vascular/metabolismo , Epoprostenol/biossíntese , Linfócitos/fisiologia , Análise de Variância , Adesão Celular , Membrana Celular/metabolismo , Células Cultivadas , Selectina E/metabolismo , Endotélio Vascular/ultraestrutura , Ácidos Graxos Ômega-3/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Linfócitos/ultraestrutura , Molécula 1 de Adesão de Célula Vascular/metabolismoRESUMO
Prostacyclin (PGI2) contributes to the maintenance of a nonadhesive luminal surface in blood vessels due to its anti-platelet and vasodilatory properties. Here, we sought to determine whether peripheral blood lymphocytes (PBL) may regulate the PGI2 production of human umbilical vein endothelial cells (HUVEC). Cell-cell contact between HUVEC and lymphocytes markedly enhanced PGI2 synthesis as a function of the number of lymphocytes added. This stimulated synthesis was totally suppressed when lymphocytes and HUVEC were separated by a microporous insert. It was not due to prostaglandin H synthase up-regulation. The pretreatment of lymphocytes with the PGI2 synthase inhibitor tranylcypromine partially inhibited PGI2 synthesis (47%), suggesting a transcellular metabolism of the endothelial prostaglandin endoperoxide PGH2 by the lymphocyte PGI2 synthase. Experiments using [14C]arachidonate-labeled lymphocytes coincubated with unlabeled HUVEC, and [14C]arachidonate-labeled HUVEC coincubated with unlabeled lymphocytes showed that the arachidonic acid used for PGI2 synthesis was totally of endothelial origin. Furthermore, the PGI2 synthesis was strongly inhibited by the cytosolic phospholipase A2 inhibitor, MAFP and totally suppressed by the combination of the calcium chelators, BAPTA and EGTA. Collectively, these results suggest that lymphocytes trigger an outside-in signaling in endothelial cells involving cPLA2 activation. Overall, the switch-on for PGI2 synthesis induced by lymphocytes might serve as a protection against atherothrombogenesis.
Assuntos
Ácido Egtázico/análogos & derivados , Endotélio Vascular/citologia , Epoprostenol/biossíntese , Regulação da Expressão Gênica/imunologia , Isoenzimas/fisiologia , Linfócitos/fisiologia , Fosfolipases A/fisiologia , Adulto , Ácido Araquidônico/metabolismo , Ácidos Araquidônicos/farmacologia , Arteriosclerose/metabolismo , Arteriosclerose/prevenção & controle , Cálcio/antagonistas & inibidores , Cálcio/fisiologia , Adesão Celular , Células Cultivadas , Quelantes/farmacologia , Técnicas de Cocultura , Meios de Cultivo Condicionados , Ciclo-Oxigenase 1 , Ciclo-Oxigenase 2 , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Ácido Egtázico/farmacologia , Endotélio Vascular/enzimologia , Inibidores Enzimáticos/farmacologia , Epoprostenol/genética , Fosfolipases A2 do Grupo IV , Humanos , Recém-Nascido , Oxirredutases Intramoleculares/antagonistas & inibidores , Oxirredutases Intramoleculares/metabolismo , Isoenzimas/metabolismo , Lipopolissacarídeos/farmacologia , Proteínas de Membrana , Organofosfonatos/farmacologia , Fosfolipases A2 , Prostaglandina H2 , Prostaglandina-Endoperóxido Sintases/metabolismo , Prostaglandinas H/metabolismo , Tranilcipromina/farmacologia , Veias UmbilicaisRESUMO
We have previously reported that concanavalin A (ConA) stimulation of rat thymocytes induces an increase in the cellular phosphatidic acid mass as well as a change in its fatty acid composition. An increase in phosphodiesterase (PDE) activity, mostly due to cAMP-specific (PDE4) isoforms, has also been observed in thymocytes stimulated by ConA. Furthermore, phosphatidic acid was able to stimulate PDE4 activity in vitro. In the present study, cAMP levels have been shown to decrease upon ConA stimulation of thymocytes. Decreasing phosphatidic acid level using diacylglycerol kinase inhibitors induced a parallel decrease of the ConA-stimulated cAMP-specific PDE activity in these cells. Analyses of phosphatidic acid molecular species in cells stimulated for 5 min by ConA revealed a significant increase in 1-stearoyl-2-arachidonoyl-sn-glycerol-3-phosphate and a relative decrease in the other molecular species of phosphatidic acid, mainly species containing palmitate. On the other hand, phosphatidic acid extracted from ConA-stimulated cells activated more efficiently the recombinant PDE4A5 isoform in vitro, as compared to phosphatidic acid extracted from unstimulated cells. In addition, phosphatidic acid species containing unsaturated fatty acids were stimulatory, while those containing two saturated fatty acids had only a marginal effect on the enzyme activity. Taken together, these data suggest that the mitogenic stimulation of thymocytes is accompanied by the synthesis of peculiar phosphatidic acid molecular species able to activate a PDE4 isoform. This activation might be of physiological relevance since cAMP is a major negative effector of the mitogenic response.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Ácidos Fosfatídicos/metabolismo , Timo/efeitos dos fármacos , Animais , Concanavalina A , Diacilglicerol Quinase , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Masculino , Ácidos Fosfatídicos/biossíntese , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/metabolismo , Timo/citologia , Timo/metabolismoRESUMO
Stimulation of rat thymocytes by concanavalin A (Con A) results in a very early increase of the cellular level of phosphatidic acid (PA), while that of diacylglycerol (DAG) was not affected. As the biological activity of PA is very likely to be determined by its molecular species composition, the present study aims to investigate the pathways leading to the production of PA in Con A-stimulated rat thymocytes. Prelabeling the cells with [3H]arachidonic acid, [3H]myristic acid, [3H]choline, or [14C]lysophosphatidylcholine allowed us to determine that PA is formed by both phosphoinositide (PIs) and phosphatidylcholine (PC) hydrolysis. We then investigated whether PA derived from PC was formed by phospholipase C (PLC) or phospholipase D (PLD) hydrolysis. In the presence of 1-butanol, the production of phosphatidylbutanol was only observed in tetradecanoyl phorbol acetate (TPA)-stimulated cells. The use of a specific PC phospholipase C inhibitor resulted in a decrease of Con A-stimulated PA production in cells labeled with [3H]myristate. When cells were labeled with [3H]choline, only TPA stimulation induced a release of labeled choline. All together, these experiments suggest that PA is originated from two phospholipid sources, predominantly PI via PLC hydrolysis and to a lesser extent PC, by PLC hydrolysis also. Molecular species analyses by reverse phase HPLC are in agreement with this hypothesis, as diacyl-GP molecular species composition is similar to that of diacyl-GPC and DAG in resting cells, but resembles that of diacyl-GPI in Con A-treated cells. Thus, in stimulated cells, the amount of 18:0/20:4 species doubled while those of saturated and monounsaturated species decreased.
Assuntos
Concanavalina A/farmacologia , Ácidos Fosfatídicos/biossíntese , Fosfatidilcolinas/metabolismo , Fosfatidilinositóis/metabolismo , Timo/efeitos dos fármacos , Timo/metabolismo , Animais , Ácido Araquidônico/metabolismo , Diglicerídeos/biossíntese , Hidrólise , Masculino , Fosfolipase D/metabolismo , Ratos , Ratos Sprague-Dawley , Acetato de Tetradecanoilforbol/farmacologia , Trítio , Fosfolipases Tipo C/metabolismoRESUMO
The appearance of 13C in rat lipoprotein, blood cells, and brain lipids was followed as a function of time after the ingestion of triglycerides (TG) containing [13C]22:6n-3. The time course of 13C abundance in 22:6n-3 of various lipid pools, measured by gas chromatography combustion-isotope mass spectrometry, established precursor-product relationships within lipids. The [13C]22:6n-3 was rapidly incorporated into very low density lipoprotein-chylomicron-TG and unesterified fatty acids bound to albumin, with a concomitant maximal appearance at 3 h and further decline. Lysophosphatidylcholines (lysoPC) bound to albumin were also enriched in [13C]22:6n-3, and their labeling appeared to be mainly due to hepatic secretion at the earliest time points. From 12 h postingestion, the synthesis of [13C]22:6n-3-lysoPC was twice as high as that of unesterified [13C]22:6n-3, making lysoPC a potential source of 22:6n-3 supply for tissues. The labeling of platelets, red blood cells, and brain phospholipids presented different kinetics, presumably involving the two lipid forms of [13C]22:6n-3 bound to albumin, to different extents. We conclude that [13C]22:6n-3 esterified in TG is rapidly redistributed within blood lipoproteins and the albumin fraction and that its incorporation in lipid species bound to albumin influences its uptake by target tissues.
Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Triglicerídeos/metabolismo , Administração Oral , Animais , Células Sanguíneas/metabolismo , Encéfalo/metabolismo , Isótopos de Carbono , Lipídeos/biossíntese , Lipoproteínas/biossíntese , Masculino , Fosfolipídeos/metabolismo , Ratos , Ratos Sprague-Dawley , Albumina Sérica/biossíntese , Fatores de TempoRESUMO
Several studies have shown the potential role of phosphatidic acid (PA) as a second messenger in different cell types. Thus, PA has been shown to mimic physiological agonists leading to various cellular responses, such as neurotransmitter and hormone release, cell proliferation by modulating DNA or RNA synthesis, the expression of several proto-oncogenes and growth factors, and the stimulation of enzyme activities such as phospholipase C (PLC), protein kinases and cyclic AMP (cAMP) phosphodiesterase. Stimulation of [3H]arachidonate-labelled rat thymocytes with the mitogen lectin concanavalin A (con A) resulted in enhanced production of radiolabelled PA after only 5 min of activation. The radiolabelled PA increase corresponded to a real increase in PA mass as determined by GLC quantification of its fatty acid content. In the presence of ethanol (0.5%), formation of phosphatidylethanol was not observed after 5 min of con A activation. Pretreatment of cells with R 59022 (10 microM), a diacylglycerol (DAG) kinase inhibitor, showed an inhibition in the formation of radiolabelled PA and in PA mass. These results suggest that the PLC-DAG kinase may be the pathway for PA synthesis in the first minutes of mitogenic thymocyte activation. A detailed analysis of the fatty acid composition showed that the relative amount of unsaturated fatty acids was increased in PA from stimulated cells concomitantly with a decrease in saturated ones; in particular, arachidonic acid was increased approximately 2-fold only 2 min after con A addition whereas palmitic acid was decreased for the whole period investigated (20 min). These changes favour the hydolysis of phosphoinositides rather than phosphatidylcholines by PLC. As PA remains a minor phospholipid, these changes are unlikely to affect cell membrane fluidity; but PA being now well recognized as a potential second messenger, its increased content as well as its increased unsaturation in the fatty acyl moiety might modulate several signalling pathways or the activity of enzymes such as cyclic nucleotide phosphodiesterase, controlling in this way the cellular level of cAMP, a negative regulator of blastic transformation.
Assuntos
Ácidos Graxos/metabolismo , Ácidos Fosfatídicos/metabolismo , Timo/metabolismo , Animais , Ácido Araquidônico/metabolismo , Concanavalina A/farmacologia , Diacilglicerol Quinase , Diglicerídeos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Ativação Linfocitária , Masculino , Lipídeos de Membrana/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Pirimidinonas/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Tiazóis/farmacologia , Fatores de TempoRESUMO
The phospholipase A2 (PLA2) activity was measured in the oviduct of immature and estradiol benzoate (EB)-treated quails. The pH profiles demonstrate the presence of two PLA2 isoforms in the avian oviduct: a neutral isoform, optimally active at pH 7-7.5 and calcium independent, responsible for most of the hydrolytic activity in the immature oviduct and poorly stimulated by estradiol; and an alkaline isoform, optimally active at pH 8-9.5 and calcium dependent, with little activity in the immature tissue but markedly stimulated by EB. After EB injection, PLA2 activation occurs at first during the prereplicative period of oviduct cells (+172% at 6 h), it is dose dependent from 0.01 to 1 mg/kg EB and can be prevented by cycloheximide together with ornithine decarboxylase activation. Moreover, estradiol was inactive on cell-free extracts of immature oviducts. These results suggest that EB increases PLA2 activity through gene activation and de novo protein synthesis. The correlation between the early stimulation of PLA2 activity and the proliferation of oviduct cells is discussed.
Assuntos
Estradiol/farmacologia , Tubas Uterinas/efeitos dos fármacos , Tubas Uterinas/enzimologia , Fosfolipases A/metabolismo , Animais , Divisão Celular , Coturnix , Ativação Enzimática , Feminino , Humanos , Cinética , Fosfolipases A2RESUMO
Stimulation of rat thymocytes with the lectin ConA produced an early peak of ornithine decarboxylase (ODC) activity within 10 min. This ODC induction appeared as early as the well-known inositol phosphate accumulation following mitogenic stimulation, and may be part of the signal transduction mechanism. The distribution of counts among the inositol phosphates was constant during the overall time of Concanavalin A (ConA) stimulation. We conclude that early induction of pre-existing ODC may be independent of protein kinase C action.
Assuntos
Fosfatos de Inositol/metabolismo , Ornitina Descarboxilase/biossíntese , Linfócitos T/metabolismo , Animais , Concanavalina A/farmacologia , Ativação Enzimática , Indução Enzimática , Ativação Linfocitária , Masculino , Proteína Quinase C/metabolismo , Ratos , Ratos Endogâmicos , Transdução de Sinais , Linfócitos T/efeitos dos fármacosRESUMO
1. Both adenosine 3':5'-cyclic monophosphate and guanosine 3':5'-cyclic monophosphate phosphodiesterase activities of peripheral blood mononuclear cells were markedly decreased in elderly women as compared with young control women. 2. In contrast, the ability of these cells to bind guanosine 5'-[beta, gamma-imido]triphosphate, a non-hydrolysable analogue of guanosine 5'-triphosphate, was the same in both groups. 3. These findings are discussed in the context of the decline in immune function which occurs with increasing age.
Assuntos
2',3'-Nucleotídeo Cíclico Fosfodiesterases/sangue , Envelhecimento/sangue , Leucócitos Mononucleares/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , AMP Cíclico/sangue , GMP Cíclico/sangue , Feminino , HumanosRESUMO
Pretreatment of rat thymic lymphocytes with Concanavalin A induced a very early (30 min) and substantial increase (+90%) of the soluble cAMP phosphodiesterase activity. The crude cytosolic phosphodiesterase activity of rat thymocytes could reproducively be resolved by Mono-Q ion exchange high performance liquid chromatography into four separate phosphodiesterase peaks: a cGMP-stimulated, two cAMP-specific Rolipram-sensitive and a cGMP-inhibited cardiotrope-sensitive peaks. Concanavalin A stimulated very specifically the activity of the two predominant cAMP-specific Rolipram sensitive peaks whereas it only slightly modified the cGMP-stimulated and the cGMP-inhibited forms. The present results strongly suggest that the Rolipram-sensitive cAMP PDE activity may play a key role in the control and regulation of mitogen-induced thymocyte proliferation.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , 3',5'-GMP Cíclico Fosfodiesterases/metabolismo , Concanavalina A/farmacologia , Linfócitos/enzimologia , Pirrolidinonas/farmacologia , 3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , 3',5'-AMP Cíclico Fosfodiesterases/isolamento & purificação , 3',5'-GMP Cíclico Fosfodiesterases/antagonistas & inibidores , 3',5'-GMP Cíclico Fosfodiesterases/isolamento & purificação , Animais , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Citosol/enzimologia , Isoenzimas/isolamento & purificação , Isoenzimas/metabolismo , Cinética , Ativação Linfocitária , Milrinona , Piridonas/farmacologia , Ratos , Ratos Endogâmicos , Rolipram , Timo/citologiaRESUMO
Rats were chronically intoxicated with triethyltin in the drinking water (0.002%) for a period of 15 days. Starting with day 5 of the intoxication period a decrease in the body weight was observed and, in parallel, the development of a cerebral oedema could be followed by measuring white matter density. At the same time, an increase of phosphatidylethanolamine-N-methyltransferase and cholinephosphate cytidylyltransferase activities was noted. This increase might be a compensatory mechanism for counteracting the membrane damages induced by triethyltin.
Assuntos
Encéfalo/enzimologia , Citidina Trifosfato/metabolismo , Nucleotídeos de Citosina/metabolismo , Nucleotidiltransferases/metabolismo , Compostos de Trialquitina/toxicidade , Compostos de Trietilestanho/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Edema Encefálico/fisiopatologia , Clorofórmio , Colina-Fosfato Citidililtransferase , DNA/metabolismo , Técnicas In Vitro , Masculino , Membranas/metabolismo , Metilação , Metiltransferases/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Endogâmicos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismoRESUMO
Triethyltin intoxication induces, in vivo, a significant increase of malondialdehyde concentration in rat brain. After treatment with a Ginkgo biloba extract, an extract known to possess antiedematous and radical scavenging properties, the malondialdehyde level in the brain is significantly decreased. This suggests that a lipid peroxidation process is associated with cerebral oedema induced by triethyltin.
Assuntos
Edema Encefálico/induzido quimicamente , Compostos de Trialquitina/toxicidade , Compostos de Trietilestanho/toxicidade , Animais , Química Encefálica/efeitos dos fármacos , Edema Encefálico/tratamento farmacológico , Fígado/análise , Masculino , Malondialdeído/análise , Malondialdeído/sangue , Extratos Vegetais/uso terapêutico , Ratos , Ratos EndogâmicosRESUMO
For clarification of the beneficial effects of the extract of Ginkgo biloba (EGB) on triethyltin (TET) toxicity in rats, the phosphodiesterase (PDE) activities of the cerebral tissue were measured under in vitro and ex vivo conditions. Under in vitro conditions, low concentrations of EGB (0.25-4.0 mg/L) activated the enzyme, whereas after higher concentrations (5-250 mg/L), dose-dependent inhibition of the enzyme activity was observed. In the lower concentration range, the extract also partially restored the high-affinity PDE activity (measured with 0.25 microM cyclic AMP) of the particulate fraction of the brain inhibited by TET in vitro. In contrast, the inhibitory influence of TET on the low-affinity PDE activity (measured with 50 microM cyclic AMP) of the particulate fraction was enhanced by the extract. Although treatment with a single large dose of EGB lowered the particulate PDE activities of the brain of normal rats, no effects of the extract could be detected in animals after repeated daily administrations of EGB during a 4-day period. Curative treatment of the TET-intoxicated rats with EGB during a 7-day period accelerated the recovery of the edematous state of the white matter caused by the intoxication and also normalized the lowered PDE activity of the particulate fraction of the edematous brain tissue. Furthermore, when preventively administered, EGB counteracted both the edema formation and the fall in PDE activity observed with treatment by TET alone. These observations strongly suggest that some beneficial effects of EGB might be due to its modulating influences on cellular cyclic AMP levels via activation of membrane-bound PDE.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Encéfalo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Compostos de Trialquitina/farmacologia , Compostos de Trietilestanho/farmacologia , Animais , Encéfalo/enzimologia , Edema Encefálico/enzimologia , Masculino , Ratos , Ratos EndogâmicosRESUMO
The possible involvement of cerebral cAMP-phosphodiesterase (PDE) in the intoxication and brain edema formation after exposure to triethyltin (TET) has been studied in vitro and in vivo in the rat. In vitro studies showed an irreversible inhibition of the particulate and soluble phosphodiesterase activities. In vivo, both high i.v. single dose and repeated oral administration of low TET doses led to a significant decrease of the particulate activities. Phosphodiesterase inhibition preceded edema formation. The soluble activities were less influenced and their inhibition could be a consequence of the edema formed in the brain tissue rather than of a TET direct action upon the enzyme. Kinetic analysis of the brain particulate enzyme from the TET-treated rats showed a significant decrease in the Vmax of the substrate high affinity enzyme form when compared to controls.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Encéfalo/enzimologia , Compostos de Trialquitina/toxicidade , Compostos de Trietilestanho/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Citosol/enzimologia , Cinética , Masculino , Ratos , Ratos Endogâmicos , Frações Subcelulares/enzimologiaRESUMO
Methylation of membrane phospholipids is an important stage in the process of histamine release. This methylation reaction can be modulated by S-adenosyl-methionine (SAM) as well as by S-adenosyl-homocysteine (SAH). The influence of SAM and of SAH upon the histamine release of leucocytes from asthmatic and normal subjects were compared. In concentration of 10(-4) M, SAM enhanced spontaneous and the specifically induced histamine release. In concentration of 10(-5) M SAM enhanced the histamine release only in normals. This phenomenon could indicate a deficit in methyl-transferase activity in the asthamatics. In concentration of 10(-4) M, SAH reduced spontaneous and specifically induced histamine release, having an effect comparable to that of 10(-4) M Theophylline.
Assuntos
Liberação de Histamina/efeitos dos fármacos , Homocisteína/análogos & derivados , Leucócitos/metabolismo , S-Adenosil-Homocisteína/farmacologia , S-Adenosilmetionina/farmacologia , Alérgenos/imunologia , Cromolina Sódica/farmacologia , Humanos , Teofilina/farmacologiaRESUMO
We studied the incorporation of [3H]methyl from [3H]methyl-S-adenosylmethionine into leukocyte phospholipids. A higher incorporation in leukocytes from control subjects than from allergic subjects was noticed.
Assuntos
Asma/sangue , Leucócitos/metabolismo , Metiltransferases/metabolismo , Fosfolipídeos/metabolismo , Adulto , Membrana Celular/metabolismo , Feminino , Granulócitos/metabolismo , Humanos , Cinética , Contagem de Leucócitos , Linfócitos/metabolismo , Masculino , Metilação , Pessoa de Meia-Idade , Fosfatidiletanolamina N-Metiltransferase , S-Adenosilmetionina/metabolismoRESUMO
Phosphatidyl ethanolamine methylation was compared in alveolar macrophage membrane from asthmatic and control subjects. Phosphatidyl ethanolamine methylase activity was determined by measuring the incorporation of (3H) methyl group from (3H) adenosyl methionine into membrane phospholipids. (3H) methyl group incorporation was significantly higher in macrophages from asthmatic patients. This result is consistent with macrophage membrane activation and could signify: a membrane phospholipid pool regeneration after allergenic or toxic disturbance or an enzymatic activation by inflammatory mediators.
Assuntos
Asma/metabolismo , Macrófagos/metabolismo , Fosfatidiletanolaminas/metabolismo , Alvéolos Pulmonares/metabolismo , Adulto , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Humanos , Macrófagos/enzimologia , Macrófagos/ultraestrutura , Masculino , MetilaçãoRESUMO
In the rabbit striated muscle tissue the free and biostructured water content have been investigated using the pressing-out method. The following percent values have been found: 20% bound water to cell colloids and different cell particles, 61% biostructure-integrated water and 19% free water.