RESUMO
Canine rangeliosis (popular names: "nambi-uvú", i.e. ``bleeding ears''; "peste de sangue", i.e. ``bleeding plague''; and "febre amarela dos cães", i.e. ``yellow fever of dogs'') is a tick-borne haemolytic and haemorrhagic disease caused by the protozoan parasite Rangelia vitalii which infects erythrocytes, leukocytes, and endothelial cells of blood capillaries. Rangelia vitalii was first reported as a novel piroplasm of dogs in 1910 in Brazil, a discovery that was met with skepticism at that time. Canine rangeliosis has been diagnosed in domestic dogs not only in Brazil but also in other South American countries (Argentina and Uruguay). Rangelia vitalii infection has also been found incidentally in Brazil in wild dogs (Cerdocyon thous, the crab-eating fox). Despite the fact that researchers in the early 1900s suggested that R. vitalii was a hitherto unidentified piroplasm that would be transmitted by the tick Amblyomma aureolatum, it was not until 2012 that these hypotheses were actually confirmed by PCR and transmission studies. Molecular studies have shown that R. vitalii is related to the Babesia sensu strictu clade, but genetically different from other morphologically similar species of Babesia that infect dogs. Another difference between Babesia spp. and R. vitalii is the ability of R. vitalii to invade endothelial cells, erythrocytes, and leukocytes. Experimental infection in dogs has successfully reproduced the clinical picture and pathology of the natural disease. In this article, epidemiology, clinical signs, laboratory findings, pathogenetic mechanisms including oxidative stress and immune response, necropsy findings, microscopic lesions, diagnosis, and treatment of canine rangeliosis are reviewed. What is currently known about this protozoal disease since its first report over a century ago is presented herein.
Assuntos
Doenças do Cão/microbiologia , Piroplasmida/isolamento & purificação , Infecções Protozoárias em Animais/parasitologia , Doenças Transmitidas por Carrapatos/veterinária , Animais , Brasil/epidemiologia , Doenças do Cão/epidemiologia , Doenças do Cão/história , Cães , História do Século XX , História do Século XXI , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/história , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/história , Doenças Transmitidas por Carrapatos/parasitologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Scutia buxifolia is a native tree of Southern Brazil, Uruguay, and Argentina, which is popularly known as "coronilha" and it is used as a cardiotonic, antihypertensive and diuretic substance. The aim of this study was to assess the acute and sub-acute toxicity of the ethyl acetate fraction from the stem bark Scutia buxifolia in male and female mice. MATERIALS AND METHODS: The toxicity studies were based on the guidelines of the Organization for Economic Cooperation and Development (OECD-guidelines 423 and 407). In an acute study, a single dose of 2000 mg/kg of Scutia buxifolia was administered orally to male and female mice. Mortality, behavioral changes, and biochemical and hematological parameters were evaluated. In the sub-acute study, Scutia buxifolia was administered orally to male and female mice at doses of 100, 200, and 400mg/kg/day for 28 days. Behavioral changes and biochemical, hematological, and histological analysis were evaluated. RESULTS: The acute administration of Scutia buxifolia did not cause changes in behavior or mortality. Male and female mice presented decreased levels of platelets. Female mice presented decreased levels of leukocytes. On the other hand, in a sub-acute toxicity study, we observed no behavioral changes in male or female mice. Our results demonstrated a reduction in glucose levels in male mice treated to 200 and 400mg/kg of Scutia buxifolia. Aspartate aminotransferase (ASAT) activity was increased by Scutia buxifolia at 400mg/kg in male mice. In relation to the hematological parameters, male mice presented a reduction in hemoglobin (HGB) and hematocrit (HCT) when treated to 400mg/kg of plant fraction. Female mice showed no change in these parameters. Histopathological examination of liver tissue showed slight abnormalities that were consistent with the biochemical variations observed. CONCLUSION: Scutia buxifolia, after acute administration, may be classified as safe (category 5), according to the OECD guide. However, the alterations observed, after sub-acute administration with high doses of ethyl acetate fraction from the stem bark Scutia buxifolia, suggest that repeated administration of this fraction plant can cause adverse hepatic, renal, and hematological effects.
Assuntos
Extratos Vegetais/toxicidade , Rhamnaceae , Acetatos/química , Animais , Aspartato Aminotransferases/sangue , Feminino , Hematócrito , Hemoglobinas/análise , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Casca de Planta , Caules de Planta , Solventes/química , Testes de Toxicidade Aguda , Testes de Toxicidade SubagudaRESUMO
AIM: The purpose of this study was to investigate whether the flavonoid quercetin can prevent alterations in the behavioral tests and of cholinergic neurotransmission in rats submitted to the ethidium bromide (EB) experimental demyelination model during events of demyelination and remyelination. MAIN METHODS: Wistar rats were randomly distributed into four groups (20 animals per group): Control (pontine saline injection and treatment with ethanol), Querc (pontine saline injection and treatment with quercetin), EB (pontine 0.1% EB injection and treatment with ethanol), and EB+Querc (pontine 0.1% EB injection and treatment with quercetin). The groups Querc and Querc+EB were treated once daily with quercetin (50mg/kg) diluted in 25% ethanol solution (1ml/kg) and the animals of the control and EB groups were treated once daily with 25% ethanol solution (1ml/kg). Two stages were observed: phase of demyelination (peak on day 7) and phase of remyelination (peak on day 21 post-injection). Behavioral tests (beam walking, foot fault and inclined plane test), acetylcholinesterase (AChE) activity and lipid peroxidation in pons, cerebellum, hippocampus, hypothalamus, striatum and cerebral cortex were measured. KEY FINDINGS: The quercetin promoted earlier locomotor recovery, suggesting that there was demyelination prevention or further remyelination velocity as well as it was able to prevent the inhibition of AChE activity and the increase of lipidic peroxidation, suggesting that this compound can protect cholinergic neurotransmission. SIGNIFICANCE: These results may contribute to a better understanding of the neuroprotective role of quercetin and the importance of an antioxidant diet in humans to provide benefits in neurodegenerative diseases such as MS.
Assuntos
Neurônios Colinérgicos/efeitos dos fármacos , Doenças Desmielinizantes/prevenção & controle , Etídio/toxicidade , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Quercetina/uso terapêutico , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Neurônios Colinérgicos/fisiologia , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/fisiopatologia , Masculino , Atividade Motora/fisiologia , Fármacos Neuroprotetores/farmacologia , Quercetina/farmacologia , Distribuição Aleatória , Ratos , Ratos Wistar , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologiaRESUMO
The aim of this study was to assess whether α-tocopherol administration prevented alterations in the ectonucleotidase activities and platelet aggregation induced by high-fat diet in rats. Thus, we examined four groups of male rats which received standard diet, high-fat diet (HFD), α-tocopherol (α-Toc), and high-fat diet plus α-tocopherol. HFD was administered ad libitum and α-Toc by gavage using a dose of 50 mg/kg. After 3 months of treatment, animals were submitted to euthanasia, and blood samples were collected for biochemical assays. Results demonstrate that NTPDase, ectonucleotide pyrophosphatase/phosphodiesterase, and 5'-nucleotidase activities were significantly decreased in platelets of HFD group, while that adenosine deaminase (ADA) activity was significantly increased in this group in comparison to the other groups (P < 0.05). When rats that received HFD were treated with α-Toc, the activities of these enzymes were similar to the control, but ADA activity was significantly increased in relation to the control and α-Toc group (P < 0.05). HFD group showed an increased in platelet aggregation in comparison to the other groups, and treatment with α-Toc significantly reduced platelet aggregation in this group. These findings demonstrated that HFD alters platelet aggregation and purinergic signaling in the platelets and that treatment with α-Toc was capable of modulating the adenine nucleotide hydrolysis in this experimental condition.
Assuntos
Dieta Hiperlipídica , Nucleotídeos/metabolismo , Agregação Plaquetária , alfa-Tocoferol/farmacologia , Animais , RatosRESUMO
The aim of this study was to investigate neurochemical and enzymatic changes in rats infected with Trypanosoma evansi, and their interference in the cognitive parameters. Behavioural assessment (assessment of cognitive performance), evaluation of cerebral L-[3H]glutamate uptake, acetylcholinesterase (AChE) activity and Ca+2 and Na+, K+-ATPase activity were evaluated at 5 and 30 days post infection (dpi). This study demonstrates a cognitive impairment in rats infected with T. evansi. At 5 dpi memory deficit was demonstrated by an inhibitory avoidance test. With the chronicity of the disease (30 dpi) animals showed anxiety symptoms. It is possible the inhibition of cerebral Na+, K+-ATPase activity, AChE and synaptosomal glutamate uptake are involved in cognitive impairment in infected rats by T. evansi. The understanding of cerebral hostparasite relationship may shed some light on the cryptic symptoms of animals and possibly human infection where patients often present with other central nervous system (CNS) disorders.
Assuntos
Ansiedade/parasitologia , Interações Hospedeiro-Parasita , Trypanosoma/fisiologia , Tripanossomíase/fisiopatologia , Acetilcolinesterase/metabolismo , Animais , Ataxia , Comportamento Animal , ATPases Transportadoras de Cálcio/metabolismo , Transtornos Cognitivos , Cães , Ácido Glutâmico/análise , Humanos , Masculino , Aprendizagem em Labirinto , Sistema Nervoso/química , Parasitemia , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/metabolismo , Trítio/análise , Tripanossomíase/parasitologiaRESUMO
BACKGROUND: Rangelia vitalii is a tick-transmitted piroplasm that causes both hemolytic and hemorrhagic disease in dogs in Brazil. OBJECTIVE: The aim of this study was to evaluate the response of the bone marrow in dogs experimentally infected with R vitalii during the acute stage of the disease. METHODS: For this study, 2 groups of a total of 12 young dogs were used. Group A was composed of healthy dogs (n = 5), and group B consisted of animals infected with R vitalii (n = 7). Blood samples were collected on days 0, 10, 20, and 30 post-inoculation and stored in EDTA tubes for a full hematology profile, including a reticulocyte count. On days 10 and 20, bone marrow samples were collected, stained, and examined. RESULTS: In infected dogs anemia was identified on days 10 and 20 post-inoculation (P < .01), and on day 20 reticulocytosis was present. Infected dogs had leukopenia due to neutropenia and eosinopenia, along with lymphocytosis and monocytosis, when compared with control animals. In bone marrow, the myeloid:erythroid ratio was significantly decreased (P < .05) in infected dogs due to increased erythroid precursors. CONCLUSIONS: Dogs experimentally infected with R vitalii develop regenerative extravascular hemolytic anemia accompanied by erythroid hyperplasia in the bone marrow. During the acute phase of the disease, leukopenia due to neutropenia and eosinopenia suggests intense tissue recruitment of these cells in response to the endothelial damage caused by this parasite.
Assuntos
Anemia Hemolítica/veterinária , Babesia/classificação , Babesiose/veterinária , Medula Óssea/patologia , Doenças do Cão/parasitologia , Anemia Hemolítica/parasitologia , Animais , Antiprotozoários/uso terapêutico , Babesiose/sangue , Babesiose/tratamento farmacológico , Babesiose/parasitologia , Babesiose/patologia , Diminazena/análogos & derivados , Diminazena/uso terapêutico , Doenças do Cão/sangue , Doenças do Cão/tratamento farmacológico , Doenças do Cão/patologia , Cães , Células Eritroides/patologia , Feminino , Hiperplasia/veterináriaRESUMO
The purpose of the present investigation was to evaluate the hydrolysis of adenine nucleotides on synaptosomes and platelets obtained from rats exposed to cadmium (Cd) and treated with N-acetylcysteine (NAC). Rats received Cd (2 mg/kg) and NAC (150 mg/kg) by gavage every other day for 30 days. Animals were divided into four groups (n = 4-6): control/saline, NAC, Cd, and Cd/NAC. The results of this study demonstrated that NTPDase and 5'-nucleotidase activities were increased in the cerebral cortex synaptosomes of Cd-poisoned rats, and NAC co-treatment reversed these activities to the control levels. In relation to hippocampus synaptosomes, no differences on the NTPDase and 5'-nucleotidase activities of Cd-poisoned rats were observed and only the 5'-nucleotidase activity was increased by the administration of NAC per se. In platelets, Cd-intoxicated rats showed a decreased NTPDase activity and no difference in the 5'-nucleotidase activity; NAC co-treatment was inefficient in counteracting this undesirable effect. Our findings reveal that adenine nucleotide hydrolysis in synaptosomes and platelets of rats were altered after Cd exposure leading to a compensatory response in the central nervous system and acting as a modulator of the platelet activity. NAC was able to modulate the purinergic system which is interesting since the regulation of these enzymes could have potential therapeutic importance. Thus, our results reinforce the importance of the study of the ecto-nucleotidases pathway in poisoning conditions and highlight the possibility of using antioxidants such as NAC as adjuvant against toxicological conditions.
Assuntos
5'-Nucleotidase/metabolismo , Acetilcisteína/farmacologia , Plaquetas/efeitos dos fármacos , Cádmio/farmacologia , Sequestradores de Radicais Livres/farmacologia , Pirofosfatases/metabolismo , Sinaptossomos/efeitos dos fármacos , Análise de Variância , Animais , Encéfalo/ultraestrutura , Masculino , Ratos , Ratos WistarRESUMO
The present study aimed to evaluate the serum proteinogram, acute phase proteins (APPs) and immunoglobulins (Igs) of dogs experimentally infected by Rangelia vitalii in the acute phases of the disease. Banked serum samples collected on days 0, 10 and 20 during a previously reported R. vitalii experimental infection were used to analyze the serum proteinogram, APPs (C-reactive protein - CRP and alpha-1-acid glycoprotein - AGP) and Igs (IgM, IgG, IgA and IgE) in the current study. Total protein and albumin level were significantly (P<0.05) decreased at day 10 PI and 20 PI in infected sera compared to the control sera. Alpha-1 globulin (day 10 PI) and gamma globulin (day 20 PI) were increased (P<0.01) in infected sera. Alpha-2 globulin (days 10 and 20 PI) and beta-2 globulin (day 10 PI) were decreased (P<0.05) in infected sera compared to control sera. Beta-1 globulin fraction did not differ statistically between sera. Serum CRP and AGP concentrations were significantly increased (P<0.05) at days 10 and 20 PI in infected sera. IgG was increased at days 10 (P<0.05) and 20 PI (P<0.01) in infected sera. Furthermore, it was also observed an increase (P<0.01) in the levels of IgM, IgA, and IgE in infected sera than control sera. We conclude that R. vitalii infection causes alterations in the proteinogram, and increases in the levels of APPs and Igs. Further studies are essentials to define the causes of these pathological changes in this disease.
Assuntos
Proteínas de Fase Aguda/metabolismo , Proteínas Sanguíneas/metabolismo , Doenças do Cão/metabolismo , Imunoglobulinas/metabolismo , Piroplasmida/fisiologia , Infecções Protozoárias em Animais/metabolismo , Animais , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Cães , Infecções Protozoárias em Animais/imunologia , Infecções Protozoárias em Animais/parasitologiaRESUMO
The potent activity against Trypanosomes and health beneficial effects of curcumin (Cur) has been demonstrated in various experimental models. In this study, we evaluated the in vivo effect of Cur as trypanocide and as potential anti-inflammatory agent, through the evaluation of immunomodulatory mechanisms in rats infected with Trypanosoma evansi. Daily oral Cur was administered at doses of 0, 20 or 60mg/kg as preventive treatment (30 and 15days pre infection) and as treatment (post infection). The treatment of the groups continued until the day of euthanasia. Fifteen days after inoculation, parasitemia, plasma proinflammatory cytokines (IFN-γ, TNF-α, IL-1, IL-6), anti-inflammatory cytokines (IL-10) and blood acetylcholinesterase activity (AChE) were analyzed. Pretreatment with Cur reduced parasitemia and lethality. Cur inhibited AChE activity and improved immunological response by cytokines proinflammatory, fundamental during T. evansi infection. We found that Cur is not so important as an antitrypanosomal activity but as immunomodulator agent. These findings reveal that the preventive use of Cur stimulates anti-inflammatory mechanisms, reducing an excessive inflammatory response.
Assuntos
Acetilcolinesterase/sangue , Anti-Inflamatórios não Esteroides/farmacologia , Curcumina/farmacologia , Citocinas/sangue , Fatores Imunológicos/farmacologia , Tripanossomíase/imunologia , Acetilcolinesterase/metabolismo , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Curcumina/administração & dosagem , Curcumina/uso terapêutico , Citocinas/metabolismo , Modelos Animais de Doenças , Fatores Imunológicos/uso terapêutico , Masculino , Parasitemia , Distribuição Aleatória , Ratos , Ratos Wistar , Trypanosoma/efeitos dos fármacos , Trypanosoma/imunologia , Tripanossomíase/tratamento farmacológico , Tripanossomíase/enzimologia , Tripanossomíase/prevenção & controleRESUMO
AIMS: We investigated whether the treatment with anthocyanins prevents the scopolamine-induced memory deficits and whether ectonucleotidase activities and purine levels are altered in the cerebral cortex (CC) and hippocampus (HC) in this model of mnemonic deficit in rats. MAIN METHODS: The animals were divided into 4 experimental groups: control (vehicle), anthocyanins (Antho), scopolamine (SCO), and scopolamine plus anthocyanins (SCO+Antho). After seven days of treatment, they were tested in the inhibitory avoidance task and open field test and submitted to euthanasia. The CC and the HC were collected for biochemical assays. The effect of treatment with Antho (200 mgkg(-1), i.p.) was investigated in rats trained to a stable level of performance and post-treated with SCO (1 mgkg(-1), i.p. 30 min after training). KEY FINDINGS: The treatment with SCO decreased the step-down latency in inhibitory avoidance task. Antho prevented the scopolamine-induced memory impairment and also the increase of NTPDase activity in the CC and HC. Furthermore, the treatment with anthocyanins prevents the decrease in 5'-nucleotidase activity and the increase in adenosine deaminase activity induced by SCO in HC. In addition, the treatment with Antho prevented the decrease in ATP levels induced by SCO in the CC and HC. SIGNIFICANCE: Our results show that scopolamine may affect purinergic enzymatic cascade or cause alterations in energy metabolism inducing loss of memory. In contrast Antho could reverse these changes, suggesting a neuroprotective effect of Antho on ectonucleotidase activities and neuronal energetic metabolism.
Assuntos
Antocianinas/farmacologia , Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/prevenção & controle , Nucleotidases/metabolismo , Escopolamina/toxicidade , Análise de Variância , Animais , Antocianinas/metabolismo , Aprendizagem da Esquiva/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , L-Lactato Desidrogenase/metabolismo , Masculino , Ratos , Ratos Wistar , Sinaptossomos/metabolismoRESUMO
The present study aimed to investigate the influence of N-acetylcysteine (NAC) on cadmium (Cd) poisoning by evaluating Cd concentration in tissues, hematological indices as well as the activity of NTPDase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes of rats exposed to Cd and co-treated with NAC. For this purpose, the rats received Cd (2 mg/kg) and NAC (150 mg/kg) by gavage every other day for 30 days. Animals were divided into four groups (n = 6-8): control/saline, NAC, Cd, and Cd/NAC. Cd exposure increased Cd concentration in plasma, spleen and thymus, and NAC co-treatment modulated this augment in both lymphoid organs. Cd exposure reduced red blood cell count, hemoglobin content and hematocrit value. Cd intoxication caused a decrease in total white blood cell count. NAC treatment per se caused an increase in lymphocyte and a decrease in neutrophil counts. On contrary, Cd exposure caused a decrease in lymphocyte and an increase in neutrophil and monocyte counts. NAC reversed or ameliorated the hematological impairments caused by Cd poisoning. There were no significant alterations in the NTPDase activity in lymphocytes of rats treated with Cd and/or NAC. Cd caused a decrease in the activities of lymphocyte AChE, whole blood AChE and serum BChE. However, NAC co-treatment was inefficient in counteracting the negative effect of Cd in the cholinesterase activities. The present investigation provides ex vivo evidence supporting the hypothesis that Cd induces immunotoxicity by interacting with the lymphoid organs, altering hematological parameters and inhibiting peripheral cholinesterase activity. Also, it highlights the possibility to use NAC as adjuvant against toxicological conditions.
Assuntos
Acetilcolinesterase/metabolismo , Acetilcisteína/farmacologia , Antígenos CD/metabolismo , Apirase/metabolismo , Butirilcolinesterase/metabolismo , Cádmio/farmacologia , Acetilcolinesterase/sangue , Acetilcisteína/administração & dosagem , Animais , Antígenos CD/sangue , Apirase/antagonistas & inibidores , Apirase/sangue , Butirilcolinesterase/sangue , Cádmio/administração & dosagem , Cádmio/sangue , Linfócitos/efeitos dos fármacos , Linfócitos/enzimologia , Linfócitos/metabolismo , Masculino , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
Several chemical and immunohistochemical techniques can be used for the detection of acetylcholinesterase (AChE) activity. In this experiment we aimed to detect AChE activity in Trypanosoma evansi. For this, the parasites were isolated from the blood of experimentally infected rats using a DEA-cellulose column. Enzymatic activity was determined in trypomastigote forms at 0, 0.2, 0.4, 0.8 and 1.2 mg/mL of protein concentrations by a standard biochemical protocol. At all concentrations tested, the study showed that T. evansi expresses the enzyme AChE and its activity was proportional to the concentration of protein, ranging between 0.64 and 2.70 µmol of AcSCh/h. Therefore, we concluded that it is possible to biochemically detect AChE in T. evansi, an enzyme that may be associated with vital functions of the parasite and also can be related to chemotherapy treatments, as further discussed in this article.
Assuntos
Acetilcolinesterase/análise , Trypanosoma/enzimologia , Acetilcolina/metabolismo , Acetilcolinesterase/fisiologia , Animais , Bioquímica/métodos , Cromatografia DEAE-Celulose , Humanos , Linfócitos/enzimologia , Linfócitos/parasitologia , Parasitemia/parasitologia , Ratos , Espectrofotometria , Tripanossomíase/parasitologiaRESUMO
The aim of this study is to evaluate the role of cholinesterases as an inflammatory marker in acute and chronic infection by Trypanosoma evansi in rabbits experimentally infected. Twelve adult female New Zealand rabbits were used and divided into two groups with 6 animals each: control group (rabbits 1-6) and infected group (rabbits 7-12). Infected group received intraperitoneally 0.5 mL of blood from a rat containing 108 parasites per animal. Blood samples used for cholinesterases evaluation were collected on days 0, 2, 7, 12, 27, 42, 57, 87, 102 and 118 days post-inoculation (PI). Increased activity (P<0.05) of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) were observed in the blood on days 7 and 27, respectively and no differences were observed in cholinesterase activity in other periods. No significant difference in AChE activity (P>0.05) was observed in the encephalic structures. The increased activities of AChE and BChE probably have a pro-inflammatory purpose, attempting to reduce the concentration of acetylcholine, a neurotransmitter which has an anti-inflammatory property. Therefore, cholinesterase may be inflammatory markers in infection with T. evansi in rabbits.
Assuntos
Acetilcolinesterase/sangue , Butirilcolinesterase/sangue , Tripanossomíase/enzimologia , Doença Aguda , Animais , Biomarcadores/sangue , Doença Crônica , Feminino , Parasitemia/sangue , Coelhos , RatosRESUMO
Resveratrol is a phytoestrogen that has many beneficial actions. This study aimed to evaluate the effect of resveratrol on the complete blood count (CBC) and the acetylcholinesterase (AChE) activity of lymphocytes of ovariectomized rats experimentally demyelinated by ethidium bromide (EB). Forty adult female Wistar rats (60 days, 200-220 g) were divided randomly into five groups (n = 4) to evaluate the demyelination phase and five groups (n = 4) to evaluate the remyelination phase. In each phase, the groups consisted of sham rats-G1; ovariectomized rats, not demyelinated, treated only with vehicle (ethanol 25%)-G2; demyelinated ovariectomized rats treated only with vehicle-G3; ovariectomized rats, not demyelinated, treated with resveratrol-G4; and demyelinated ovariectomized rats treated with resveratrol-G5. Only during the remyelination phase, CBC showed a significant difference (p < 0.05) in the number of monocytes between G2 and G5 groups. In the demyelination phase, there was a significant decrease (p < 0.05) in the AChE activity in the G4 group, while the G5 group was statistically similar to the G1, G2 and G4 groups. In the remyelination phase, there were no significant differences in the AChE activity among the groups. The treatment for 7 days with resveratrol with or without the experimental demyelization with EB appears to influence the AChE activity of lymphocytes, without changing the number of these cells in the circulation. However, in the remyelination phase, there seems to be stabilization in its effect on the lymphocyte AChE activity.
Assuntos
Acetilcolinesterase/sangue , Anti-Inflamatórios não Esteroides/farmacologia , Doenças Desmielinizantes/sangue , Linfócitos/enzimologia , Ovariectomia , Estilbenos/farmacologia , Animais , Contagem de Células Sanguíneas , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/patologia , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/farmacologia , Etídio/efeitos adversos , Etídio/farmacologia , Feminino , Linfócitos/patologia , Ratos , Ratos Wistar , ResveratrolRESUMO
Rangeliosis is a disease which affects dogs in Brazil, caused by a piroplasm known as Rangelia vitalii. This disease causes a lot of clinico-pathological features, including the coagulation disorders associated with bleeding. The cause of these changes has not yet been determined. Considering the association of purinergic system and hemostasis this study aimed to evaluate the activity of enzymes that hydrolyze ATP, ADP and AMP; and deamination of adenosine in platelets from dogs experimentally infected with R. vitalii. For this study, 12 healthy young dogs (females) were used, separated in two groups. Group A (n=5) were uninfected controls, and group B were experimentally infected with R. vitalii (n=7). After being inoculated with R. vitalii-infected blood, animals were monitored by blood smear examinations, which showed intra-erythrocytic forms of the parasite after five days post-inoculation (PI). Blood samples were collected to quantitate and separate platelets (Day 0, 12 and 21 PI) and to measure the enzymatic activities (Day 12 and 21 PI). The activity of NTPDase, 5'-nucleotidase and adenosine deaminase (ADA) was measured in platelets. A reduction (P<0.01) in the number of platelets was observed in R. vitalii-infected blood at Days 12 and 21 PI. At Day 12 PI, a reduction (P<0.01) in the hydrolysis of ATP, ADP and AMP, and deamination of adenosine was observed in dogs infected with R. vitalii. At Day 21 PI the ADA activity remained decreased, unlike the activity of NTPDase which increased (P<0.05). Based on these results we can conclude that ATP, ADP and AMP hydrolysis and adenosine deamination were altered in platelets of R. vitalii-infected dogs. Considering the importance of the purinergic system in hemostasis, it is believed that those changes contribute to the coagulation disorders and bleeding observed in R. vitalii-infected dogs and discussed in this manuscript.
Assuntos
Adenosina Desaminase/sangue , Babesia/fisiologia , Babesiose/veterinária , Plaquetas/enzimologia , Doenças do Cão/sangue , Nucleotidases/sangue , Adenosina/metabolismo , Difosfato de Adenosina/metabolismo , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Babesiose/sangue , Babesiose/enzimologia , Transtornos da Coagulação Sanguínea/parasitologia , Transtornos da Coagulação Sanguínea/veterinária , Brasil , Desaminação , Doenças do Cão/enzimologia , Doenças do Cão/parasitologia , Cães , Feminino , Hemorragia/parasitologia , Hemorragia/veterinária , Hidrólise , Contagem de Plaquetas/veterináriaRESUMO
The aim of this study was to evaluate lipid peroxidation, protein oxidation and activity of enzymes that are indicators of oxidative stress in Rangelia vitalii infection in dogs. Animals were divided into two groups: negative control (n=5) and infected with R. vitalii (n=7). After inoculation, the parasitemia was estimated daily by microscopic examination of smears. Lipid peroxidation (TBARS) and advanced oxidation protein products (AOPP); and delta-aminolevulinate dehydratase (δ-ALA-D), superoxide dismutase (SOD) and catalase (CAT) activities in blood were evaluated. The samples were collected at days 10 and 20 post-inoculation (PI). TBARS and AOPP levels were higher in the infected group in both analyzed periods (P<0.01). The δ-ALA-D activity was reduced in blood of dogs infected with R. vitalii on days 10 and 20 PI. SOD activity was significantly increased (P<0.01) in the blood of dogs infected with R. vitalii at days 10 and 20 PI, while CAT activity was significantly increased (P<0.01) only at day 20 PI when compared to non-infected animals. A positive correlation was observed between the degree of parasitemia and TBARS and AOPP levels and activity of antioxidant enzymes. The δ-ALA-D activity was negatively correlated with the degree of parasitemia. Based on the increased levels of TBARS, AOPP, SOD and CAT activities, and inhibition δ-ALA-D activity, we concluded that dogs experimentally infected with R. vitalii develop a state of redox unbalance and that these changes might be involved in the pathophysiology of disease.
Assuntos
Apicomplexa/fisiologia , Doenças do Cão/parasitologia , Estresse Oxidativo/fisiologia , Infecções Protozoárias em Animais/parasitologia , Produtos da Oxidação Avançada de Proteínas/metabolismo , Animais , Apicomplexa/classificação , Catalase/genética , Catalase/metabolismo , Cães , Feminino , Regulação Enzimológica da Expressão Gênica , Parasitemia , Sintase do Porfobilinogênio/genética , Sintase do Porfobilinogênio/metabolismo , Infecções Protozoárias em Animais/patologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Sporotrichosis is a fungal infection of subcutaneous or chronic evolution, inflammatory lesions characterized by their pyogranulomatous aspect, caused by the dimorphic fungus Sporothrix schenckii. Adenosine deaminase (ADA) is a "key" enzyme in the purine metabolism, promoting the deamination of adenosine, an important anti-inflammatory molecule. The increase in ADA activity has been demonstrated in several inflammatory conditions; however, there are no data in the literature associated with this fungal infection. The objective of this study was to evaluate the activity of serum ADA (S-ADA) and lymphocytes (L-ADA) of rats infected with S. schenckii. We used seventy-eight rats divided into two groups. In the first experiment, rats were infected subcutaneously and in the second experiment, infected intraperitoneally. Blood samples for hematologic evaluation and activities of S-ADA and L-ADA were performed at days 15, 30, and 40 post-infection (PI) to assess disease progression. In the second experiment, it was observed an acute decrease in activity of S-ADA and L-ADA (P < 0.05), suggesting a compensatory mechanism in an attempt to protect the host from excessive tissue damage. With chronicity of disease the rats in the first and second experiment at 30 days PI showed an increased activity of L-ADA (P < 0.05), promoting an inflammatory response in an attempt to combat the spread of the agent. Thus, it is suggested that infection with S. schenckii alters the activities of S-ADA in experimentally infected rats, demonstrating the involvement of this enzyme in the pathogenesis of sporotrichosis.
Assuntos
Adenosina Desaminase/sangue , Interações Hospedeiro-Patógeno , Soro/química , Sporothrix/imunologia , Sporothrix/patogenicidade , Esporotricose/imunologia , Esporotricose/patologia , Animais , Linfócitos/enzimologia , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Ovarian hormone loss contributes to cognitive decline in postmenopausal women. Studies have demonstrated a positive role of the level of the element selenium in cognitive performance. The present study investigated the effects of the synthetic organoselenium compound diphenyl diselenide (PhSe)2 on cognitive functions in ovariectomized rats. Ninety-day-old female Wistar rats were subjected to ovariectomy (OVX) or Sham operation. One week after surgery, rats were orally treated with (PhSe)2 (5 mg/kg, per oral route) or vehicle once a day for 30 days. Next, the rats were evaluated in behavioral tests [Morris water maze (MWM) and open-field tests] and biochemical [cerebral acetylcholinesterase (AChE)] analyses were carried out. In MWM probe trial, (PhSe)2 decreased the latency to reach the platform location and increased the number of crossings over the platform location, protecting against cognitive impairment induced by OVX. Furthermore, (PhSe)2 prevented the stimulation of AChE activity caused by OVX. In conclusion, the present study showed a cognition-enhancing effect of (PhSe)2 treatment for 30 days in ovariectomized rats in the MWM test, which could be related to its ability to prevent the stimulation of AChE activity caused by OVX in rats. These findings suggest that (PhSe)2 might have a promising role in preventing the cognitive decline related to menopause.
Assuntos
Derivados de Benzeno/uso terapêutico , Transtornos Cognitivos/tratamento farmacológico , Menopausa/psicologia , Compostos Organosselênicos/uso terapêutico , Acetilcolinesterase/metabolismo , Animais , Feminino , Aprendizagem em Labirinto , Modelos Animais , Ovariectomia , Ratos , Ratos WistarRESUMO
The aim of this study was evaluate changes in the cholinesterase activity in blood, lymphocytes and serum of rats infected with Leptospira interrogans serovar Icterohaemorrhagiae ('L. icterohaemorrhagiae'). Sixty adult Wistar rats were divided into six groups of 10 animals: three control groups and three test groups. The animals from the test groups were intraperitoneally inoculated with 1 ml medium containing 1 × 10(8) leptospires. The activity of acetylcholinesterase in blood and butyrylcholinesterase in serum increased on days 5 (P<0.05) and 30 (P<0.021) post-infection, respectively. A decrease in lymphocyte count was observed on days 15 (P<0.01) and 30 post-infection (P<0.05). On day 15 post-infection, acetylcholinesterase activity (P<0.001) in lymphocytes decreased in infected rats. However, on day 30 post-infection there was an increase in acetylcholinesterase activity in lymphocytes. In conclusion, our results showed that the activity of enzymes of the cholinergic system in the total blood, lymphocytes and serum is altered as a result of inflammation caused by infection with L. icterohaemorrhagiae. The possible causes of these alterations will be discussed in this paper.
Assuntos
Acetilcolinesterase/sangue , Butirilcolinesterase/sangue , Leptospira interrogans serovar icterohaemorrhagiae/patogenicidade , Leptospirose/patologia , Linfócitos/enzimologia , Animais , Leptospirose/microbiologia , Contagem de Linfócitos , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
The aim of this study was to evaluate the platelet count, coagulation time and platelet activity in dogs experimentally infected with Rangelia vitalii during the acute phase of the disease. For this study, 12 young dogs (females) were used, separated in two groups. Group A (uninfected control) was composed by healthy dogs (n=5), and group B consisted of R. vitalii-infected animals (n=7). After being inoculated with R. vitalii-infected blood, animals were monitored by blood smear examinations, which showed intra-erythrocytic forms of the parasite five days post-inoculation (PI). Blood samples were collected on days 0, 10, 20 and 30 PI. The material collected was placed in tubes containing EDTA for quantification of platelets, citrate anticoagulant platelet aggregation, and measuring the clotting time. Right after blood collection on days 10 and 20 PI, dogs were anesthetized for collecting bone marrow samples. A significant reduction (P<0.01) of the number of platelets was observed in R. vitalii-infected blood, when compared with uninfected dogs on days 10 and 20 PI. Additionally, macro-platelets were observed only in infected dogs. Prothrombin time and activated partial thromboplastin time did not differ between infected and uninfected dogs. The megakaryocyte count increased (P<0.01) significantly in infected dogs when compared with uninfected ones on days 10 and 20 PI. Platelet aggregation decreased (P<0.01) significantly in infected dogs in comparison to the control on days 10 and 20 PI. Therefore, rangeliosis in dogs causes a severe thrombocytopenia during the acute phase of infection. This platelets reduction probably occurred due to splenic sequestration and/or immune-mediated thrombocytopenia.