The Protective Effect of Lithium Against Rotenone may be Evolutionarily Conserved: Evidence from Eisenia fetida, a Primitive Animal with a Ganglionic Brain

Chronic exposure to stress is a non-adaptive situation that is associated with mitochondrial dysfunction and the accumulation of reactive oxygen species (ROS), especially superoxide anion (SA). This accumulation of ROS produces damage-associated molecular patterns (DAMPs), which activate chronic inflammatory states and behavioral changes found in several mood disorders. In a previous study, we observed that an imbalance of SA triggered by rotenone (Ro) exposure caused evolutionarily conserved oxi-inflammatory disturbances and behavioral changes in Eisenia fetida earthworms. These results supported our hypothesis that SA imbalance triggered by Ro exposure could be attenuated by lithium carbonate (LC), which has anti-inflammatory properties. The initial protocol exposed earthworms to Ro (30 nM) and four different LC concentrations. LC at a concentration of 12.85 mg/L decreased SA and nitric oxide (NO) levels and was chosen to perform complementary assays: (1) neuromuscular damage evaluated by optical and scanning electron microscopy (SEM), (2) innate immune inefficiency by analysis of Eisenia spp. extracellular neutrophil traps (eNETs), and (3) behavioral changes. Gene expression was also evaluated involving mitochondrial (COII, ND1), inflammatory (EaTLR, AMP), and neuronal transmission (nAchR α5). LC attenuated the high melanized deposits in the circular musculature, fiber disarrangement, destruction of secretory glands, immune inefficiency, and impulsive behavior pattern triggered by Ro exposure. However, the effects of LC and Ro on gene expression were more heterogeneous. In summary, SA imbalance, potentially associated with mitochondrial dysfunction, appears to be an evolutionary component triggering oxidative, inflammatory, and behavioral changes observed in psychiatric disorders that are inhibited by LC exposure.

Rotenone-exposure as cytofunctional aging model of human dermal fibroblast prior replicative senescence

Rotenone (Ro), causes superoxide imbalance by inhibiting complex I of the mitochondrial electron transport chain, being able to serve as a model for functional skin aging by inducing cytofunctional changes in dermal fibroblasts prior to proliferative senescence. To test this hypothesis, we conducted an initial protocol to select a concentration of Ro (0.5, 1, 1.5, 2, 2.5, and 3 μM) that would induce the highest levels of the aging marker beta-galactosidase (β-gal) in human dermal HFF-1 fibroblasts after 72 h of culture, as well as a moderate increase in apoptosis and partial G1 arrestment. We evaluated whether the selected concentration (1 μM) differentially modulated oxidative and cytofunctional markers of fibroblasts. Ro 1.0 μM increased β-gal levels and apoptosis frequency, decreased the frequency of S/G2 cells, induced higher levels of oxidative markers, and presented a genotoxic effect. Fibroblasts exposed to Ro showed lower mitochondrial activity, extracellular collagen deposition, and fewer fibroblast cytoplasmic connections than controls. Ro triggered overexpression of the gene associated with aging (MMP-1), downregulation genes of collagen production (COL1A, FGF-2), and cellular growth/regeneration (FGF-7). The 1 μM concentration of Ro could serve as an experimental model for functional aging fibroblasts prior to replicative senescence. It could be used to identify causal aging mechanisms and strategies to delay skin aging events.

A coffee enriched with guarana, selenium, and l-carnitine (GSC) has nutrigenomic effects on oxi-inflammatory markers of relapsing-remitting multiple sclerosis patients: A pilot study

Relapsing-remitting multiple sclerosis (RRMS) is the most common clinical course of multiple sclerosis (MS), characterized by a chronic inflammatory state and elevated levels of oxidative markers. Food supplements with potential anti-inflammatory, antioxidant and neuroprotective effects have been tested as possible adjuvants in the treatment of MS. In this sense, this pilot study was carried out with the aim of verifying whether a minimum daily dose of a guarana, selenium and l-carnitine (GSC) based multi supplement, mixed in cappuccino-type coffee, administered for 12 weeks to 28 patients with RRMS could differentially modulate oxidative blood markers (lipoperoxidation, protein carbonylation and DNA oxidation) and inflammatory blood markers (protein levels of cytokines IL-1β, IL-6, TNF-α, IFN-γ, IL-10, gene expression of these cytokines, and NLRP3 and CASP-1 molecules, and C-reactive protein levels). The results indicate that a low concentration of GSC is capable of decreasing the plasma levels of oxidized DNA and pro-inflammatory cytokines of RRMS patients. The results support further research into the action of GSC on clinical symptoms, not only in patients with MS, but also with other neurological conditions.

Superoxide-imbalance pharmacologically induced by rotenone triggers behavioral, neural, and inflammatory alterations in the Eisenia fetida earthworm

BACKGROUND

Some studies have suggested that mitochondrial dysfunction and a superoxide imbalance could increase susceptibility to chronic stressful events, contributing to the establishment of chronic inflammation and the development of mood disorders. The mitochondrial superoxide imbalance induced by some molecules, such as rotenone, could be evolutionarily conserved, causing behavioral, immune, and neurological alterations in animals with a primitive central nervous system.

OBJECTIVE

Behavioral, immune, and histological markers were analyzed in Eisenia fetida earthworms chronically exposed to rotenone for 14 days.

METHODS

Earthworms were placed in artificial soil containing 30 nM of rotenone distributed into a plastic cup that allowed the earthworms to leave and return freely into the ground. Since these organisms prefer to be buried, the model predicted that the earthworms would necessarily have to return to the rotenone-contaminated medium, creating a stressful condition. The effect on survival behavior in the immune and histological body wall and ventral nervous ganglia (VNG) structures, as well as gene expression related to inflammation and mitochondrial and neuromuscular changes.

RESULTS

Rotenone-induced loss of earthworm escape behavior and immune alterations indicated a chronic inflammatory state. Some histological changes in the body wall and VNG indicated a possible earthworm reaction aimed at protecting against rotenone. Overexpression of the nicotinic acetylcholine receptor gene (nAChR α5) in neural tissues could also help earthworms reduce the degenerative effects of rotenone on dopaminergic neurons.

CONCLUSION

These data suggest that mitochondrial dysfunction could be an evolutionarily conserved element that induces inflammatory and behavioral changes related to chronic stress.

Superoxide-anion triggers impairments of immune efficiency and stress response behaviors of Eisenia fetida earthworms

Superoxide-hydrogen peroxide (S-HP), triggered by Val16Ala-SOD2 human polymorphism, may influence the risk of depression. Therefore, it is plausible that higher basal S-anion levels and chronic inflammatory states associated with the VV-SOD2 genotype can negatively modulate the stress response associated with resilience in various species, from primitive species to humans. To test this hypothesis, Eisenia fetida earthworms were exposed for 24 h to 30 nM rotenone, which causes mitochondrial dysfunction by generating high S-anion levels (known as the "VV-like phenotype"), and 10 μM porphyrin, a SOD2-like compound, which generates elevated HP levels (known as the "AA-like phenotype"). The results suggested that both S-anion and HP acted as signaling molecules, differentially altering the immune function and acute hydric stressful response. Although the AA-like phenotype improved the immune and stress response efficiencies, the VV-like phenotype showed a downregulated expression of the toll-like receptor (EaTLR, JX898685) and antimicrobial peptide (AMP) (AF060552) genes, which triggered the impairment of encapsulation and earthworms extracellular trap (EET) processes used by earthworms to trap and destroy microorganisms. When exposed to adverse environments and dangerous hydric stress, VV-like earthworms exhibited an impulsive behavior and failed to quickly identify and migrate to a protected environment, unlike control earthworms and AA-like earthworms. All results corroborated that the S-anion imbalance could concomitantly induce alterations in immune function and stress behavior related to earthworm survival. From a human perspective, this information may corroborate the potential specific role of superoxide anion in the modulation of the stress response, resilience, and risk of depression.

Avocado oil (Persea americana) protects SH-SY5Y cells against cytotoxicity triggered by cortisol by the modulation of BDNF, oxidative stress, and apoptosis molecules

Chronic psycho-environmental stress can induce neurological dysfunction due to an increase in cortisol levels. It is possible that some food supplements could attenuate its negative impact, such as avocado oil (AO), which is rich in fatty acids with beneficial effects on the brain. This hypothesis was tested by an in vitro model using undifferentiated neuroblastoma cells (SH-SY5Y) exposed to hydrocortisone (HC), an active cortisol molecule with and without AO-supplementation. Cortisol can induce oxidative stress, apoptosis events, and a lowering effect on brain-derived neurotrophic factor (BDNF), a neurogenic molecule. As AO protective effects on HC-exposed cells could involve these routes, some markers of these routes were compared among neuroblastoma cultures. In the first assay, the range concentrations of HC exposure that trigger cell mortality and range AO-concentrations that could revert the HC effect. AO at all concentrations tested (2-30 µg/ml) did not present a cytotoxic effect on SH-SY5Y cells, whereas HC at 0.3-10 ng/ml had a dose-dependent cytotoxic effect on these cells. From these results, HC at 10 ng/ml and AO at 5 µg/ml were chosen for mechanistic analysis. AO was able to decrease the oxidative molecules; however, both AO- and HC-induced differential and varied gene expression modulation of these enzymes. AO partially reverted the protein and gene expression of apoptotic markers that were higher in HC-exposed cells. AO also increases the BDNF levels, which are lower HC-exposed cultures. The results indicate that AO could be a beneficial supplement in situations where cortisol levels are elevated, including chronic psycho-environmental stress. PRACTICAL APPLICATIONS: Psychological chronic stress that induces high cortisol exposure has been linked to premature aging and decreased healthy life expectancy. Neurobiological models involving cortisol have suggested a neurotoxic effect of this molecule, increasing the risk of psychiatric and other CNTDs. This effect can have a high impact mainly in infants and elderly people. In child abuse situations, chronic cortisol exposure could induce extensive apoptosis events, causing impairment in synaptogenesis. In both age groups, chronic cortisol exposure increased the risk of psychiatric conditions, especially anxiety and major depression. However, it is possible that the negative effects associated with chronic cortisol exposure could be attenuated by some food supplements. This is the case for molecules acquired through diet, such as polyunsaturated fatty acids (PUFAs), including omega-3. As inadequate omega-3 levels in the brain can increase the risk factor for neuropsychiatric disorders, it is possible to infer that some from food supplements, such as avocado oil, could attenuate the neurotoxic effects of chronic cortisol exposure. This hypothesis was tested using an exploratory in vitro protocol, and the results suggested that avocado oil could be used as a cytoprotective food supplement by decreasing the oxidative stress and apoptotic events induced by cortisol.

Unmetabolized quetiapine exerts an in vitro effect on innate immune cells by modulating inflammatory response and neutrophil extracellular trap formation

Quetiapine is an antipsychotic drug that is used to treat psychiatric and neurological disorders. Despite its efficiency and low-toxicity, quetiapine administration has been associated with undesirable side effects such as the development of low-grade inflammatory disorders and neutropenia states. As the liver rapidly metabolizes quetiapine to metabolites, the non-metabolized part of this molecule might play a role in immune alterations. In an in vitro study, this hypothesis was tested by exposing activated and inactivated RAW-264.7 macrophages and human neutrophils to unmetabolized quetiapine (u-QUE). Based on our findings, u-QUE was not cytotoxic to these cells. u-QUE differentially modulates macrophages according to their activation states. In inactivated macrophages, u-QUE induced a proinflammatory state as observed by an increase in cellular proliferation; increased levels of oxidative molecules (nitric oxide and superoxide), protein levels, and gene overexpression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α); and decreased levels of IL-10, an anti-inflammatory cytokine. Conversely, on phytohemagglutinin (PHA)-activated macrophages, u-QUE exerted an anti-inflammatory effect. u-QUE induced neutrophil extracellular trap (NET) formation and increased the sensitivity of the neutrophils previously activated by exposure to dead yeast cells for NET formation. These results confirm the effect of quetiapine on macrophage and neutrophil function, which may be associated with the side effects of this psychopharmaceutical agent.

In vitro effect of low-level laser therapy on the proliferative, apoptosis modulation, and oxi-inflammatory markers of premature-senescent hydrogen peroxide-induced dermal fibroblasts

Skin aging is a complex biological process induced by intrinsic and extrinsic factors which is characterized by clinical and cellular changes, especially dermal fibroblasts. It is possible that, some procedures, such as low-level laser therapy (LLLT), could decelerate this process. To test this hypothesis, this study evaluated the in vitro LLLT on dermal fibroblast cell line (HFF-1) with premature senescence H2O2-induced. HFF-1 cells were cultured in standardized conditions, and initially H2O2 exposed at different concentrations. Fibroblasts were also just exposed at different LLLT (660 nm) doses. From these curves, the lowest H2O2 concentration that induced indicators of premature senescence and the lowest LLLT doses that triggered fibroblast proliferation were used in all assays. Cellular mortality, proliferation, and the levels of oxidative, inflammatory cytokines, apoptotic markers, and of two growth signaling molecules (FGF-1 and KGF) were compared among treatments. The H2O2 at 50 μM concentration induced some fibroblast senescence markers and for LLLT, the best dose for treatment was 4 J (p < 0.001). The interaction between H2O2 at 50 μM and LLLT at 4 J showed partially reversion of the higher levels of DNA oxidation, CASP 3, CASP 8, IL-1B, IL-6, and INFy induced by H2O2 exposure. LLLT also trigger increase of IL-10 anti-inflammatory cytokine, FGF-1 and KGF levels. Cellular proliferation was also improved when fibroblasts treated with H2O2 were exposed to LLLT (p < 0.001). These results suggest that in fibroblast with some senescence characteristics H2O2-induced, the LLLT presented an important protective and proliferative action, reverting partially or totally negative effects triggering by H2O2.

Lithium is able to minimize olanzapine oxidative-inflammatory induction on macrophage cells

Background

Olanzapine (OLZ) is a second-generation antipsychotic drug used for treatment of schizophrenia, bipolar disorder, and other neuropsychiatric conditions. Undesirable side effects of OLZ include metabolic alterations associated with chronic oxidative-inflammation events. It is possible that lithium (Li), a mood modulator that exhibits anti-inflammatory properties may attenuate OLZ-induced oxi-inflammatory effects.

Methodology

To test this hypothesis we activated RAW 264.7 immortalized macrophages with OLZ and evaluated oxidation and inflammation at the gene and protein levels. Li and OLZ concentrations were determined using estimated plasma therapeutic concentrations.

Results

OLZ triggered a significant increase in macrophage proliferation at 72 h. Higher levels of oxidative markers and proinflammatory cytokines, such as TNF-α, IL-1β, and IL-6, with a concomitant reduction in IL-10, were observed in OLZ-exposed macrophages. Lithium (Li) exposure triggered a short and attenuated inflammatory response demonstrated by elevation of superoxide anion (SA), reactive oxygen species (ROS), IL-1β, and cellular proliferation followed by elevation of anti-inflammatory IL-10 levels. Li treatment of OLZ-supplemented macrophages was able to reverse elevation of oxidative and inflammatory markers and increase IL-10 levels.

Conclusions

Despite methodological limitations related to in vitro protocols, results suggested that Li may attenuate OLZ-induced oxidative and inflammatory responses that result from metabolic side effects associated with OLZ.

The anti-inflammatory effects of resveratrol on human peripheral blood mononuclear cells are influenced by a superoxide dismutase 2 gene polymorphism

Resveratrol is an molecule that provides both anti-inflammatory and antioxidant properties. However, it is unclear whether the basal oxidative state of the cell has any influence on the effects of this compound. In humans, a single nucleotide polymorphism (SNP) is present in the enzyme manganese superoxide dismutase (SOD2), localized in codon 16 (rs4880), which can either be an alanine (A) or valine (V). This SNP causes an imbalance in the cellular levels of SOD2, where AA- and VV-genotypes result in higher or lower enzymatic activity, respectively. Furthermore, the VV-genotype has been associated with high levels of inflammatory cytokines. Here, we examined the effects of a range of resveratrol concentrations on the in vitro activation of human peripheral blood mononuclear cells (PBMCs) carrying different Ala16Val-SOD2 genotypes. Cell proliferation, several oxidative biomarkers and cytokines (IL-1β, IL-6, TNFα, Igγ and IL-10) were analyzed. In addition, the effects of resveratrol on the expression of the sirt1 gene were evaluated by qRT-PCR. After 24 h exposure to resveratrol, A-genotype PBMCs displayed a decrease in cell proliferation, whilst VV-cells contrasted; At 10 µM resveratrol, there was a significant decrease in the production of inflammatory cytokines in A-allele cells; however, VV-cells generally displayed a subtle decrease in these, except for TNFα, which was not affected. In all SOD2 genotypes cells exposed to resveratrol resulted in an upregulation of Sirt1 levels. Together, these results suggest that the effect of resveratrol on human PBMC activation is not universal and is dependent on the Ala16Val-SOD2 SNP.

Bothrops asper and Bothrops jararaca snake venoms trigger microbicidal functions of peritoneal leukocytes in vivo

Venoms from snakes of the genus Bothrops cause pronounced local effects in the victims. These alterations result not only from the direct toxic action of venom components, but also from the prominent inflammatory reaction associated with these envenomations. In this study we investigated the ability of Bothrops asper (BaV) and Bothrops jararaca (BjV) venoms to induce cellular influx and microbicidal functions in leukocytes. BaV and BjV (5 microg/animal) caused a long lasting infiltration of leukocytes (3-48 h) when injected into mouse peritoneal cavity. Both venoms increased phagocytosis and production of hydrogen peroxide (H2O2) by polymorphonuclear (PMN) and mononuclear (MN) peritoneal leukocytes. In addition, nitric oxide (NO) production by macrophages was also enhanced after the venom injections. This effect was inhibited by treating animals with L-NAME and aminoguanidine, thus suggesting the induction of iNOS synthesis by the venoms. Western blot analysis confirmed the expression of iNOS in macrophages. BaV and BjV injection led to increased levels of IFN-gamma at the site of inflammation. Since IFN-gamma is an effective inducer of iNOS expression, an indirect action of the venoms on iNOS expression can be proposed. A marked formation of nitrotyrosine-containing proteins was also observed in macrophage homogenates. Based on these results, we suggest that reactive oxygen and nitrogen-derived species are involved in the pathogenesis of the local tissue damage characteristic of Bothrops sp envenomations.

Cytochemical study of Streptococcus agalactiae and macrophage interaction

Light and electron microscopy were used to analyse the process of interaction of Streptococcus agalactiae (serotypes Ia, III, and V) with resident and activated mouse peritoneal macrophages. Transmission electron microscopy showed that adherence of the S. agalactiae serotype Ia, but not III and V serotypes, to the surface of activated macrophages triggers the respiratory oxidative burst as revealed by the presence of reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H]-oxidase in the phagocytic vacuoles. Fusion of macrophage lysosomes with bacteria-containing phagocytic vacuoles was observed in macrophages treated with Lucifer yellow as well as by localization of acid phosphatase for all serotypes.

Pharmacological modulation of hyperalgesia induced by Bothrops asper (terciopelo) snake venom

The ability of Bothrops asper snake venom to cause hyperalgesia was investigated in rats, using the paw pressure test. Intraplantar injection of the venom (5-15 microg/paw) caused a dose and time-related hyperalgesia, which peaked 2h after venom injection. Bothrops asper venom-induced hyperalgesia was blocked by the bradykinin B(2) receptor antagonist HOE 140 and attenuated by dexamethasone, an inhibitor of phospholipase A(2). Inhibition of the lipoxygenase pathway by NDGA abrogated the algogenic phenomenon. The hyperalgesic response was not modified by pretreatment with indomethacin, an inhibitor of the cyclo-oxygenase pathway, by meloxicam, an inhibitor of the type 2 cyclo-oxygenase pathway, by the PAF receptor antagonist BN52021 or by anti-TNF-alpha or anti-interleukin 1 antibodies. Intraplantar injection of the venom also caused an oedematogenic response which was not modified by any of these pharmacological treatments. These results suggest that hyperalgesia induced by Bothrops asper venom is, at least partially, mediated by bradykinin, phospholipase A(2) activity and leukotrienes. Distinct mechanisms are involved in the development of hyperalgesia and oedema induced by the venom.

Increments in serum cytokine and nitric oxide levels in mice injected with Bothrops asper and Bothrops jararaca snake venoms

Changes in serum levels of several cytokines and nitric oxide were studied in BALB/c mice injected intraperitoneally with one median lethal dose (LD(50)) of the venoms of Bothrops asper and Bothrops jararaca, two of the medically most important poisonous snakes of Latin America. Despite differences observed in the time-course of cytokine increments and in serum cytokine levels, both venoms induced prominent elevations of TNF-alpha, IL-1, IL-6, IL-10 and IFN-gamma. There was an early increase in TNF-alpha and IL-1, followed by a more pronounced increment by 18 h. IL-6 levels peaked between 4 and 6 h, and this cytokine probably modulates the secretion of TNF-alpha and IL-1 and the synthesis of acute-phase proteins. Both venoms induced an early increment in serum IL-10, whereas IFN-gamma levels reached higher values in mice injected with B. jararaca venom than in those receiving B. asper venom. Serum nitric oxide concentration increased in mice injected with both venoms rapidly after envenomation, remaining elevated for 24 h. It is concluded that a complex pattern of cytokine and nitric oxide synthesis and secretion occurs in severe experimental envenomation by B. asper and B. jararaca venoms. Furthermore, it is suggested that some of these mediators, particularly TNF-alpha, IL-1 and nitric oxide, might play a relevant role in the pathophysiology of systemic alterations induced by these venoms.

Platelet-activating factor and eicosanoids are mediators of local and systemic changes induced by immune-complexes in mice

A passive Arthus reaction (AR) induced in the peritoneal cavity of mice was followed by increased local vascular permeability and haemoconcentration. The intensity of the increased vasopermeability was higher in BALB/c compared with C3H/HePas mice despite the latter being 10 times more sensitive to platelet-activating factor (PAF). C3H/HePas mice however, exhibited higher levels of haemoconcentration and shock-like symptoms. Both events were inhibited by the PAF antagonist, WEB 2170. Indomethacin reduced both pathological events whereas L663,536, that inhibits leukotrienes synthesis reduced haemoconcentration but only in BALB/c mice. PAF was released into the peritoneal cavity, peak release being at 10 min after induction of AR. Prostaglandin E2 (PGE2), thromboxane B2 (TXB2), leukotriene B4 (LTB4), and leukotriene C4/D4 (LTC4/D4) were also released at this time. Similar levels of PAF and eicosanoids were found in BALB/c and C3H/HePas mice except for LTB4, which was higher in C3H/HePas. It is concluded that PAF and eicosanoids are mediators of local and systemic changes induced by immune complexes in the peritoneal cavity of mice.

Lipid mediators, tumor necrosis factor and nitric oxide and their interactions in immune-complex-induced lung injury

We investigated the contribution of eicosanoids, platelet-activating factor, tumor necrosis factor and nitric oxide to the neutrophil influx and development of pulmonary haemorrhagic lesions following immune-complex-induced pneumonitis in rats and possible interactions between these mediators. Increased levels of leukotriene B4 and tumor necrosis factor, measured by enzyme immunoassay and L-929 cytotoxicity assay, were found in the bronchoalveolar lavage 1 and 4 h after induction of the reaction, respectively, and their release was dependent on the previous generation of platelet activating factor. Antagonism of leukotriene B4 receptors by RO-0254094 (2-[(5-carboxypentyl])oxy]-6-[6-[3,4-dihydro-4-oxo-8-propyl-2H-1-benzopy ran-7-yl)oxy]hexyl] benzenepropanoic acid), inhibition of nitric oxide synthesis by L-NAME (Nw-nitro-L-arginine methyl ester) and antagonism of PAF-receptors by WEB-2170 (5-(2-chlorphenyl)-3-4-dihydro-10-methyl-3-((4-morpholinyl)carbony l)-2 H,7H-cyclopenta (4,5)thieno(3,2-f)(1,2,4)-triazolo-4,3,a)91,4)diazepine), significantly inhibited the intensity of haemorrhage, evaluated by the increased levels of extravascular hemoglobin in homogenates of lung tissues. Little evidence support the role of tumor necrosis factor in these lesions. The infiltration of neutrophils, evaluated by measuring myeloperoxidase in homogenates of lungs, was reduced by compounds L-663,536 (3-[1-(4 chlorobenzyl)-3-t-butyl thio-5-isopropylindol-2-yl]-2-2-dimethylpropanoic acid), WEB-2170 and L-NAME. These results indicate that neutrophil infiltration and haemorrhagic lesions in immune-complex-induced lung inflammation are mediated by platelet activating factor, leukotriene B4 and nitric oxide and point out to interesting interactions between these mediators.

Lack of effect of endogenous corticosteroids on the acute inflammatory reaction (edema) induced by Bothrops jararaca venom (BjV) in rats

Intraplantar injection of 5 or 10 micrograms of BjV caused local edema in rats that was not affected by ablation of adrenal glands. In addition, no changes in plasma corticosterone levels were observed. Simultaneous injections of the venom into both hindpaws of normal animals, or injections made at varying intervals, resulted in local inflammatory reactions of comparable time-course development and analogous magnitude. These data might be related to an inability of the venom to evoke secretion of corticosteroids.

Leukocyte response induced by Bothrops jararaca crude venom: in vivo and in vitro studies

The effect of Bothrops jararaca crude venom (BjV) on the cellular component of inflammatory responses was investigated in vivo and in vitro. In vivo leukocyte accumulation and release of eicosanoids (thromboxane A2, TXA2, and leukotriene B4, LTB4) at the site of injection of the venom were assessed using the air pouch method in rats. Administration of BjV caused a significant cell accumulation, maximal values being obtained after 6-8 hr. Neutrophils were the predominant cell type in the inflammatory exudate. High concentrations of LTB4 were detected 1-4 hr after the injection of the venom. TXA2 concentrations were significantly increased only at the early stages of the response to the venom. In vitro chemotaxis assays were performed and showed that the venom per se was not able to induce oriented neutrophil migration because varying concentrations of the venom dissolved in Hanks' balanced salt solution (HBSS) evoked a response equivalent to that of HBSS alone. Furthermore, the venom did not affect cellular intrinsic mechanisms involved with neutrophil locomotion because previous incubation of the cells with BjV produced no effect. However, high concentrations of the venom were able to generate serum chemotactic factor(s). Incubation of serum with the venom evoked a neutrophil migration similar to that observed with serum activated by lipopolysaccharide from Escherichia coli. Participation of chemotactic factors derived from the complement system is suggested by data showing loss of this activity when serum was heated (56 degrees C) before the addition of BjV. The present results suggest that leukocyte accumulation in the locality of a lesion induced by BjV is dependent on secretion or activation of endogenous components responsible for several steps in leukocyte recruitment instead of a direct effect of the venom on leukocytes.

Increased permeability of bovine aortic endothelial cell monolayers in response to a thromboxane A2-mimetic

The present study was designed to investigate the ability of thromboxane to modulate the clearance rate of 125I-albumin through bovine aortic endothelial cell (BAEC) monolayer grown on polycarbonate micropore membrane. Stimulation of BAEC with the TXA2 mimetic U44069 (10(-8), 10(-7) and 10(-6) M) elicited a dose-dependent increase of labeled albumin passage across BAEC monolayers. This effect was markedly reduced by the TXA2 antagonist L655240 (10(-7) and 10(-6) M). Our results suggest that TXA2 may modulate the permeability of endothelial cells directly through activation of specific receptors.

Edematogenic responses induced by Bothrops jararaca venom in rats: role of lymphocytes

The intraplantar injection of Bothrops jararaca venom (Bjv) caused an edematogenic response in the rat which was of rapid onset, and reached a peak in about 60 min. The response was markedly attenuated in animals rendered leucopenic by the administration of amethopterin. This inhibition was partially reverted when leucopenic rats were given i.v. suspensions of lymphocytes. Suspensions of neutrophils were ineffective. If the animals were submitted to an experimental obstruction of the thoracic duct, which leads to specific lymphocytopenia, similar inhibition of the edematogenic response was observed. These results suggest that lymphocytes can directly influence the development of the edema induced by Bothrops jararaca venom.

Hyperalgesia induced by Bothrops jararaca venom in rats: role of eicosanoids and platelet activating factor (PAF)

In this study we investigated the ability of Bothrops jararaca venom (BjV) to induce hyperalgesia and the modulation of this effect by lipid mediators. It was found that intraplantar injection of BjV (1 to 25 micrograms) caused a dose and time-related hyperalgesia. The peak of the hyperalgesic response was 1 hr after injection of the venom and persisted for 24 hr with the higher dose. The BjV-induced hyperalgesia was markedly attenuated by dexamethasone. Dexamethasone blocks the generation of biologically active metabolites from arachidonic acid by inhibiting PLA2 activation. Inhibition of the cyclo-oxygenase pathway by indomethacin, or inhibition of lipoxygenases by NDGA both significantly inhibited BjV-induced hyperalgesia. Two antagonists of PAF, WEB2170 and BN52021, also significantly inhibited the initial phase of the hyperalgesia. These results suggest that hyperalgesia induced by BjV is, at least partially, mediated by lipid mediators such as prostaglandins, leukotrienes and PAF.

O contexto político-administrativo da implantação de Distritos Sanitários no Estado da Bahia, Brasil

O presente trabalho foi realizado com o objetivo de caracterizar o contexto político-administrativo da implantação dos Distritos Sanitários na Bahia. Procedeu-se a uma revisão documental abrangendo acordos, convênios e leis, nos âmbitos estadual e federal, no período compreendido entre 1987 e 1989, correspondente à primeira fase da gestão estadual após as eleições de 1986. As informações foram completadas através de entrevistas com informantes-chave e ex-dirigentes do nível central da Secretaria Estadual de Saúde. Descreve-se o processo de formulação da política de regionalização territorial e populacional e faz-se uma revisão do processo de planificação, a níveis nacional e estadual, com a identificação dos eventos que conduziram à decisão de se criar os Distritos Sanitários. São listados os instrumentos de política que materializaram esta decisão e analisada a posição dos distintos atores do sistema de saúde em relação a esta opção estratégica de reorientação da organização dos serviços. Conclui-se com breves comentários sobre as dificuldades que esta proposta encontra para institucionalizar-se no período em estudo.

Inhibitory effect of econazole on the release of thromboxanes

The effect of econazole on the release of thromboxanes was investigated. It was found that econazole inhibited concentration-dependently the aggregation of guinea pig platelets stimulated with arachidonic acid. The compound also reduced significantly the LTB4-induced contraction of guinea pig lung parenchyma strips and the contraction of rabbit aorta to the effluent of LTD4-stimulated guinea pig lungs, both effects mediated mostly by thromboxane generation. The concentration of TXB2 in the effluents from LTD4 stimulated lungs, assayed by EIA, was significantly reduced following pretreatment of the lungs with 10(-4) M and 10(-5) M of econazole, whereas the levels of PGE2 were increased. These results demonstrate that econazole is a selective inhibitor of thromboxane synthesis.

Inhibitory effects of beryllium chloride on rat liver microsomal enzymes

A single i.v. dose (0.1 mmol Be2+/kg) of beryllium chloride prolonged the duration of pentobarbital-induced sleep and zoxazolamine-induced paralysis, in rats. The effects are correlated with changes of the pharmacokinetic parameters and with the in vitro inhibition of both aliphatic and aromatic hydroxylation of pentobarbital and zoxazolamine. In vitro N-demethylation of meperidine and aminopyrine was partially inhibited while O-demethylation of quinidine was unaffected by liver microsomes of rats pretreated with beryllium salt. The findings give clues that beryllium chloride inhibits some forms of cytochrome P-450, especially those responsible for hydroxylation of substrates, like pentobarbital and zoxazolamine.

Propylene glycol enhances anti-inflammatory effects of phenylbutazone

1. The interference of propylene glycol with anti-inflammatory effects of phenylbutazone was investigated. 2. Inhibitory effect of phenylbutazone on both carrageenin-induced edema and the cotton pellet granuloma was increased when propylene glycol was used as solvent. 3. Propylene glycol given alone inhibited carrageenin-induced edema and pleurisy, as well as granulomatous tissue formation. 4. Some pharmacokinetic parameters of phenylbutazone were also changed by propylene glycol administered simultaneously. 5. These results suggest that propylene glycol probably increases the anti-inflammatory effect of phenylbutazone by summation and by raising the plasma half-life and the distribution volume of phenylbutazone.