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Biomedical subjects

J J Moreno

Publications and source records attributed to J J Moreno.

At least 37 records · Page 2Linked to original sources
PubMed1996

Influence of superoxide radical and hydrogen peroxide on arachidonic acid mobilization.

Murine resident peritoneal macrophages can produce potent reactive oxygen species (ROS) and arachidonic acid metabolites such as eicosanoids, which have important roles in host defense and the pathogenesis of inflammation. Phagocytosis and macrophage activation are believed to enhance secretion of ROS and eicosanoids. Therefore, we investigated the influence of ROS release on arachidonate mobilization. Our results shown that ROS could be involved in the pathways that result in [3H]AA release. We suggested that phosphorylation and dephosphorylation processes stimulated by ROS could increase arachidonic acid mobilization via a PKC-independent pathway.

Animals↗
PubMed1996

Antiflammin-2, a nonapeptide of lipocortin-1, inhibits leukocyte chemotaxis but not arachidonic acid mobilization.

We have studied the effects of antiflammin-2, a fragment corresponding to amino acids 246-254 of lipocortin-1 (HDMNKVLDL), on arachidonate mobilization and metabolism and we also determined the effect of antiflammin-2 on the chemotaxis of phagocytes. Our results demonstrated that the antiflammin-2 was not able to diminish significantly [3H]arachidonic acid mobilization stimulated by 4 beta-phorbol-12-myristate 13-acetate or calcium ionophore A23187 in murine 3T6 fibroblasts or resident peritoneal macrophages. Further, antiflammin-2 had no effect on arachidonate metabolism. In contrast, a glucocorticoid such as dexamethasone reduced significantly [3H]arachidonic acid release and arachidonate metabolism induced in both cells. This study confirms the inhibitory effect of antiflammin on leukocyte migration and suggests that it acts partly through the inhibition of leukocyte binding to endothelial cells.

Animals↗
PubMed1996

Effect of degree of unsaturation in dietary fatty acids on arachidonic acid mobilization by peritoneal macrophages.

Cells from rats fed with a tripalmitin diet showed a depletion of phospholipid arachidonate and n-3 fatty acids such as eicosapentaenoic and docosahexaenoic acids (EPA and DHA). In rats fed fish oil diet, a significant reduction in arachidonic acid (AA) content was observed whereas EPA and DHA were incorporated into membranes lipids. These changes in lipid composition of membranes did not affect cellular adherence, phagocytic capability, or [3H]AA incorporation. However, both tripalmitin and fish oil diets induced a decrease in [3H]AA mobilization stimulated by 4 beta-phorbol-12-myristate 13-acetate, A23187, or opsonized-zymosan in rat peritoneal macrophages. These results demonstrate that the antiinflammatory effects of essential fatty acids deficiency or n-3 enrichment diets may be associated with a decreased AA mobilization in resident rat peritoneal macrophages treated with proinflammatory agents.

Animals↗
PubMed1996

Proliferation-dependent changes in arachidonic acid mobilization from phospholipids of 3T6 fibroblasts.

When we stimulated 3T6 fibroblasts, we observed a mobilization of arachidonic acid (AA) from phospholipids. The magnitude of this response decreased as the cells became confluent and the change coincided with a decrease in the percentage of cells in growth phases (G2 + M); this was not a consequence of the time in culture or a factor in the growth medium. Preconfluent fibroblasts incubated with the calcium ionophore A23187 (1 microM), 4beta-phorbol-12-myristate acetate (PMA, 10 microM), bradykinin (10 microM) or fetal calf serum (20%) released 38.8%, 62.5%, 11.2% and 45.6% [3H]AA, respectively. Confluent cells stimulated under the same conditions released only 16.9%, 1.5%, 0.5% and 18.5% [3H]AA, respectively. This decreasing mobilization of AA was demonstrated using metabolic labelling and measurement of prostaglandin PGE2. The decrease was not due to a changing pool of AA. [3H]AA release from each phospholipid decreased with confluence. Conversion of confluent cells to the proliferative phenotype by mechanical wounding of the monolayer increased the release of [3H]AA. This effect is consistent with regulated, growth-dependent changes in the activity of phospholipase A2, a process regulated by changes in phosphorylation of the enzyme. The increased release of [3H]AA from preconfluent, actively dividing cells may have important physiological implications and may help elucidate mechanisms regulating release of AA.

Animals↗
PubMed1996

Stimulation of arachidonic acid mobilization by adherence of resident peritoneal macrophages to plastic substrate.

To interpret results of studies on arachidonic acid (AA) mobilization and metabolism in vitro, it is essential that the influence of culture and conditions should be well defined. Thus, we investigated the effects of murine resident peritoneal macrophage adherence and the presence of foetal calf serum in culture medium on arachidonic acid mobilization. The present data demonstrate that [3H] AA mobilization was triggered simply by contact between cell and substrate. The presence of serum can modulate cell-substrate interactions but not AA mobilization. Protein kinase C, and calmodulin inhibitors failed to inhibit [3H] AA release induced by cell adherence. Finally, low molecular weight PLA2 inhibitors were not able to inhibit [3H] AA mobilization stimulated by cell adherence.

Animals↗
PubMed1996

Role of kinases and G-proteins on arachidonate release induced by zymosan in mouse peritoneal macrophages.

The present study investigated the role of kinases and G-proteins in arachidonic acid (AA) mobilization by resident mouse peritoneal macrophages in response to phagocytosis of opsonized zymosan. Stimulation of resident murine peritoneal macrophages with opsonized zymosan caused an increase in [3H] arachidonic acid release. This increase was dose-dependent and was not accompanied by de novo synthesis of proteins. Neither staurosporine, a protein kinase C inhibitor, nor genistein, a tyrosine kinase inhibitor, had any effect on [3H] AA mobilization, although trifluoperazine significantly inhibited AA release. The involvement of G proteins and phospholipase C (PLC) in the regulation of arachidonic acid release induced by opsonized zymosan was also examined in mouse peritoneal macrophages. Prior treatment of cells with pertussis toxin induced a partial decrease in AA mobilization. However, neomycin or aspirin, at doses that inhibit inositol phosphate formation (PLC activity), did not [3H] AA mobilization by PLA2. We proposed that the AA release by peritoneal macrophages in response to opsonized zymosan phagocytosis could be due to the participation of enzymes other than PLC and PKC, or proteins other than G proteins.

Analysis of Variance↗
PubMed1995

Influence of calcium on arachidonic acid mobilization by murine resident peritoneal macrophages.

Stimulation of resident peritoneal macrophages resulted in release of arachidonic acid (AA) from phospholipids. This AA release is believed to occur as a result of the activation of phospholipases, usually by a phospholipase A2 (PLA2). The purpose of this study was to elucidate the role of cytosolic calcium ion concentration ([Ca2+]i) in the modulation of [3H]AA mobilization in peritoneal macrophages. [3H]AA release induced by ionophore A23187, opsonized zymosan, or 4 beta-phorbol 12-myristate acetate (PMA) occurred in the absence of extracellular calcium. Studies in fura-2/AM-loaded cells showed that zymosan and PMA did not increase [Ca2+]i significantly, whereas A23187 induced PLA2 activity translocation up to plasmatic membrane. Thapsigargin, an inhibitor of endomembrane Ca(2+)-ATPase, induced a rise in [Ca2+]i when cells were incubated in a Ca2+ medium. However, thapsigargin was not an effective stimulator of the translocation of PLA2 activity and [3H]AA release. These data indicate that changes in [Ca2+]i were not sufficient to elicit [3H]AA mobilization; this process seems tightly modulated by phosphorylation-dependent mechanisms in the presence of low [Ca2+]i.

Animals↗
PubMed1995

Effects of an anti-inflammatory peptide (antiflammin 2) on cell influx, eicosanoid biosynthesis and oedema formation by arachidonic acid and tetradecanoyl phorbol dermal application.

Antiflammins are synthetic peptides with sequence homology to proteins inhibitory for phospholipase A2 (EC 3.1.1.4). The effect of antiflammin 2 on murine arachidonate or 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear oedema has been studied. Topical application of arachidonic acid (AA) produced a short-lived oedema response with rapid onset associated with marked increases in prostaglandin E2 levels. TPA produced a longer-lasting oedema associated with marked influx of neutrophils and mononuclear cells as well as predominant formation of leukotriene B4 (LTB4). Topical pretreatment with indomethacin or dexamethasone reduced plasma leakage, oedema and prostaglandin E2 biosynthesis in AA-induced oedema, whereas antiflammin 2 had no effect. However, topical pretreatment with antiflammin 2 dose-dependently reduced plasma leakage, cell influx, oedema and LTB4 levels in response to TPA. These results indicate that the anti-inflammatory effect of antiflammins can be attributed to AA mobilization and/or 5 lipoxygenase inhibition but can be dissociated from an effect on arachidonic acid metabolism by the cyclooxygenase pathway.

Acetylglucosaminidase↗
PubMed1995

Ca2+ influx, phosphoinositide hydrolysis, and histamine release induced by lysophosphatidylserine in mast cells.

We have previously demonstrated that snake venom phospholipases A2 (PLA2s) and mammalian PLA2s induced inflammatory processes. This effect was correlated with the activity of the enzymes and the release of lipid mediators. We have now determined the role of lysophosphatidylserine (LysoPS) as an inflammatory lipid mediator. Thus, we have studied the possibility that intracellular calcium concentration, phosphoinositide hydrolysis, and the subsequent histamine release in mast cells is due to the action of lysophosphatidylserine. Lysophosphatidylserine-stimulated release of histamine was significantly higher than release by other lysophospholipids. The contribution of increased phospholipase C activity and the intracellular Ca2+ influx were therefore examined. LysoPS increased mast cell calcium concentration, and this increment was associated with phospholipase C activation and release of inositol phosphates. The increase in intracellular calcium and histamine degranulation induced by LysoPS were inhibited by apomorphine. Pretreatment of mast cells with pertussis toxin decreased the secretagogic effect of LysoPS and compound 48/80 without modifying the effect of the ionophore A23187. These results suggest that pertussis toxin-sensitive G-protein might be involved in the mast cell degranulation produced by lysophosphatidylserine and allow the increase in phospholipase C activity, thus enhancing intracellular calcium concentration, which then induces exocytosis of histamine.

Animals↗
PubMed1994

Effect of nonapeptide fragments of uteroglobin and lipocortin I on oedema and mast cell degranulation.

The anti-inflammatory action of nonapeptide fragments of uteroglobin or lipocortin I known as antiflammins, was tested in the carrageenan or phospholipase A2 rat paw oedema model. The development of carrageenan-induced oedema in rats was significantly inhibited during the early and late phases of the oedema by the local administration of antiflammins 1 and 2. However, the peptides were not able to inhibit phospholipase A2-induced oedema. The time course of the anti-oedematous activity of nonapeptides after intradermal carrageenan injection may be attributed to their effect on mast cell degranulation and accumulation and activation of leukocytes. Naja naja phospholipase A2 exhibited strong histamine release-inducing activity, which may have contributed to the rat paw oedema induction. Surprisingly, antiflammins had a limited but significant inhibitory effect on histamine secretion.

Animals↗
PubMed1994

Immunochemical relatedness between secretory phospholipase A2 and intracellular phospholipase A2 activity linked with arachidonic acid mobilization in macrophages.

To determine whether low mol. wt phospholipase A2 (PLA2) is involved in the mechanism of arachidonic acid mobilization induced by zymosan in mouse peritoneal macrophages, we developed an immunoblot analysis and ELISA assay using the polyclonal antibodies anti-PLA2 type I and type II previously characterized. We also measured the effect of low mol. wt PLA2 inhibitors such as p-bromophenacyl bromide, aristolochic acid, nordihydroguaiaretic acid, all trans-retinal and all trans-retinoic acid on the action of these enzymes. The antibodies antitype I PLA2 bound to mouse platelet protein fraction, while the antibodies antitype I or antitype II did not recognize components of the macrophages. Furthermore, low mol. wt PLA2 inhibitors did not inhibit arachidonic acid release produced during the phagocytosis of zymosan. This suggests that low mol. wt PLA2 are not present in cells such as macrophages. These results are consistent with a role for high mol. wt PLA2 in arachidonic acid mobilization.

Acetophenones↗
PubMed1993

Oedema formation and degranulation of mast cells by phospholipase A2 purified from porcine pancreas and snake venoms.

Phospholipase A2 is ubiquitous in nature, with the highest concentrations occurring in pancreatic juice and in the venom of snakes. Local oedema formation is a common feature of the effects caused by snakebite, and indicates an increase in vascular permeability that could be produced by lipid mediators such as lysophospholipids, eicosanoids or PAF release by the enzymatic activity of PLA2. Desalted porcine pancreatic PLA2 exhibited strong oedema-inducing activity in a similar form to PLA2 venom from Naja naja or Crotalus durissus terrificus. Furthermore, all three PLA2S caused the release of histamine from rat peritoneal mast cells. However, non-desalted pancreatic PLA2 that was presented as an ammonium sulphate suspension (3.2 M) had no proinflammatory activity and clearly did not release histamine in vitro. When the enzymatic activity of PLA2 on mast cell membranes prelabelled with [3H] arachidonic acid was determined, a relationship between the enzymatic activity and mast cell degranulation and the minimum oedema dose was observed. However, non-desalted porcine pancreatic PLA2 had the same enzymatic activity as the desalted enzyme but had little proinflammatory activity. This may be due to decreased histamine secretion caused by the presence of ammonium sulphate. Our study supports the idea that the proinflammatory activity of extracellular phospholipases could depend on their ability to cause mast cell degranulation. Moreover, the biological effects of PLA2 are correlated with the specific activities of the enzymes.

Ammonium Sulfate↗
PubMed1993

Time-course of phospholipase A2, eicosanoid release and cellular accumulation in rat immunological air pouch inflammation.

Phospholipase A2 activity in the rat air pouch cavity was determined after induction of a reverse passive Arthus reaction. Time-course of phospholipase A2 activity appeared to correlate with increased prostaglandin E2 levels in inflammatory exudate and with the influx of mononuclear inflammatory cells. Local administration of anti-inflammatory drugs such as dexamethasone, indomethacin, or a PLA2 inhibitor such as p-bromophenacyl bromide significantly inhibited exudate volume, cellular influx, granuloma formation, exudate PGE2 levels and PLA2 activity, to varying degrees. Dexamethasone treatment significantly reduced all parameters determined, whereas p-bromophenacyl bromide had a significant inhibitory effect on PLA2 activity and PGE2 release, and indomethacin only restored PGE2 levels. These results show that PLA2 is neither the only nor the most important factor involved in the development of subchronic inflammation.

Acetophenones↗
PubMed1993

N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) excretion after acute administration of acetaminophen, salsalate and aspirin in rats.

The present study was performed to compare renal injury induced by high acute doses of both the nonacetylated salicylate, salsalate (SSA) and the acetylated salicylate, aspirin (ASA). As a marker of renal injury, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) were measured after oral administration of 600 mg/kg of each drug. Other tests to detect renal injury were also performed. Serum salicylic levels after SSA or ASA were determined in a different experiment. Acetaminophen (APAP) was used as a standard of renal toxicity. Both drugs increase NAG and to a greater extent, AAP excretion. Proteinuria and polyuria appear after both drugs. Changes in urinary sodium and potassium were also shown. Our results support the view that both acetylated and non-acetylated salicylates induce renal injury at toxicological doses.

Acetaminophen↗
PubMed1992

[Incidence of hip fractures in Cantabria].

BACKGROUND: Fracture of the hip constitutes a serious social/health care problem with very little information concerning incidence in Spain being available. METHODS: The diagnosis of hospital admissions and the diagnosis of release from the traumatology units of health care centers for acute patients in Cantabria were reviewed. The study was carried out from the 1st of January to the 31st of December 1988 and only included patients over 49 years of age. Patients who did not habitually reside in the region were excluded. The following data were collected in each case: age, sex, place of residence (urban or rural), time of the year, side fractured, type of injury, previous contralateral fracture and perioperative mortality. RESULTS: The rate of fracture referred to the population of more than 49 years of age was 277/100,000 in the case of females and 100/100,000 for males. The mean age of women was 80.4 +/- 8.5 years and of men was 76.9 +/- 10.9 years (p > 0.02), respectively. No differences were observed with regard to the place of residence or the time of year. The fracture was left sided in 61% of the females and 58% of the males. The injury was almost always due to a fall. Six percent of the patients had a previous contralateral fracture. Perioperative mortality was 6%. CONCLUSIONS: The incidence of hip fracture in Cantabria is similar to that of other regions in Spain and lower to that of parts of central and northern Europe and the United States.

Accidents, Home↗
PubMed1992

In vitro and in vivo effects of the anti-inflammatory peptides, antiflammins.

The anti-inflammatory synthetic polypeptides referred to as antiflammins are thought to be inhibitors of phospholipase A2 (PLA2) (EC 3.1.1.4). These peptides are from the sequence of amino acids of greatest similarity between uteroglobin and lipocortin I. The effect of these peptides was studied on PLA2 activation in rat platelets and on acute inflammatory models after local or parenteral administration of drug. We found that antiflammins decreased collagen-induced platelet activation, but had no effect when arachidonic acid was used as activator. The peptides were able to inhibit acute inflammatory processes induced by carrageenan or phorbol esters when administered locally or parenterally. However, antiflammins had no effect on inflammation induced by exogenous PLA2 administration. These results indicate that the antiflammins may have a direct inhibitory effect on PLA2 activation but not on the enzyme or enzyme-substrate interaction.

Amino Acid Sequence↗
PubMed1992

Antiflammins. Anti-inflammatory activity and effect on human phospholipase A2.

Two anti-inflammatory peptides (antiflammins) corresponding to a high amino acid similarity region between lipocortin I and uteroglobin were tested for their ability to inhibit purified human synovial fluid phospholipase A2 (HSF-PLA2). No inhibitory activity was observed, even at such high concentrations of peptides as 50 microM. When antiflammins were preincubated with the enzyme and/or the substrate, no HSF-PLA2 inhibition was detected. In vivo anti-inflammatory activity of these peptides was evaluated in several experimental models of inflammation induced by carrageenan, croton-oil, oxazolone and Naja naja naja venom phospholipase A2 (PLA2). In contrast to the in vitro results, anti-inflammatory activity was observed in all tests, except when inflammation was induced by snake venom PLA2. Taken together, our results do not support the hypothesis that the in vivo anti-inflammatory effect of antiflammins is directly related to inhibition of PLA2 activity.

Animals↗