RESUMO
The aim of this study was to investigate the effect of nerolidol-loaded nanospheres (N-NS) on the treatment of memory impairment caused by Trypanosoma evansi in mice, as well as oxidative stress, and Na+, K+-ATPase and acetylcholinesterase (AChE) activities in brain tissue. Animals were submitted to behavioral tasks (inhibitory avoidance task and open-field test) 4 days postinfection (PI). Reactive oxygen species (ROS) and thiobarbituric acid-reactive substance (TBARS) levels and catalase (CAT), superoxide dismutase (SOD), Na+, K+-ATPase and AChE activities were measured on the fifth-day PI. T. evansi-infected mice showed memory deficit, increased ROS and TBARS levels and SOD and AChE activities, and decreased CAT and Na+, K+-ATPase activities compared to uninfected mice. N-NS prevented memory impairment and oxidative stress parameters (except SOD activity), while free nerolidol (N-F) restored only CAT activity. Also, N-NS treatment was able to prevent alterations in Na+, K+-ATPase and AChE activities caused by T. evansi infection. A significantly negative correlation was observed between memory and ROS production (p < 0.001; r = -0.941), as well as between memory and AChE activity (p < 0.05; r = -0.774). On the contrary, a significantly positive correlation between memory and Na+, K+-ATPase activity was observed (p < 0.01; r = 0.844). In conclusion, N-NS was able to reverse memory impairment and to prevent increased ROS and TBARS levels due to amelioration of Na+, K+-ATPase and AChE activities and to activation of the antioxidant enzymes, respectively. These results suggest that N-NS treatment may be a useful strategy to treat memory dysfunction and oxidative stress caused by T. evansi infection.
Assuntos
Antioxidantes/administração & dosagem , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Infecções Protozoárias do Sistema Nervoso Central/tratamento farmacológico , Inibidores da Colinesterase/administração & dosagem , Nanosferas , Estresse Oxidativo/efeitos dos fármacos , Sesquiterpenos/administração & dosagem , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Trypanosoma/patogenicidade , Tripanossomíase/tratamento farmacológico , Acetilcolinesterase/metabolismo , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Encéfalo/enzimologia , Encéfalo/patologia , Catalase/metabolismo , Infecções Protozoárias do Sistema Nervoso Central/enzimologia , Infecções Protozoárias do Sistema Nervoso Central/parasitologia , Infecções Protozoárias do Sistema Nervoso Central/psicologia , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/enzimologia , Transtornos Cognitivos/parasitologia , Transtornos Cognitivos/psicologia , Modelos Animais de Doenças , Feminino , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/metabolismo , Memória/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/enzimologia , Transtornos da Memória/parasitologia , Transtornos da Memória/psicologia , Camundongos , Atividade Motora/efeitos dos fármacos , Nootrópicos/administração & dosagem , Tempo de Reação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Tripanossomíase/enzimologia , Tripanossomíase/parasitologia , Tripanossomíase/psicologiaRESUMO
The adenosine deaminase represents a control point in the regulation of extracellular adenosine levels, thus playing a critical role in the modulation of purinergic responses to certain pathophysiological events. Several studies have shown that serum and plasma enzyme levels are elevated in some diseases caused by microorganisms, which may represent a compensatory mechanism due to the elevated levels of adenosine and the release of inflammatory mediators. Recent research indicates that adenosine deaminase activity decreases and affects hematological parameters of infected animals with Trypanosoma evansi, so that such alterations could have implications in the pathogenesis of the disease. In addition, the enzyme has been detected in this parasite; allowing the inference that it could be associated with the vital functions of the same, similar to what occurs in mammals. This knowledge may be useful in the association of chemotherapy with specific inhibitors of the enzyme in future studies.
Assuntos
Adenosina Desaminase/metabolismo , Trypanosoma/enzimologia , Tripanossomíase/enzimologia , Adenosina/metabolismo , Adenosina Desaminase/sangue , Animais , Modelos Animais de Doenças , Humanos , Mediadores da Inflamação/metabolismo , Trypanosoma/isolamento & purificaçãoRESUMO
La adenosin deaminasa representa un punto de control en la regulación de los niveles extracelulares de adenosina, desempeñando así un papel fundamental en la modulación de las respuestas purinérgicas a ciertos eventos patofisiológicos. Diversos estudios señalan que los niveles séricos y plasmáticos de la enzima se elevan en algunas enfermedades causadas por microorganismos, lo cual podría representar un mecanismo compensatorio como consecuencia de la elevación de las concentraciones de adenosina y la liberación de mediadores inflamatorios. Recientes investigaciones indican que la actividad de la adenosin deaminasa disminuye e influye en los parámetros hematológicos de animales infectados con Trypanosoma evansi, de manera que tales alteraciones podrían tener implicaciones en la patogénesis de la enfermedad. Adicionalmente, la enzima ha sido detectada en este parásito; lo que permite inferir que podría estar asociada a las funciones vitales del mismo, de manera similar a lo que ocurre en los mamíferos. Este conocimiento puede ser útil al asociar la quimioterapia con inhibidores específicos de la enzima en futuros estudios.
The adenosine deaminase represents a control point in the regulation of extracellular adenosine levels, thus playing a critical role in the modulation of purinergic responses to certain pathophysiological events. Several studies have shown that serum and plasma enzyme levels are elevated in some diseases caused by microorganisms, which may represent a compensatory mechanism due to the elevated levels of adenosine and the release of inflammatory mediators. Recent research indicates that adenosine deaminase activity decreases and affects hematological parameters of infected animals with Trypanosoma evansi, so that such alterations could have implications in the pathogenesis of the disease. In addition, the enzyme has been detected in this parasite; allowing the inference that it could be associated with the vital functions of the same, similar to what occurs in mammals. This knowledge may be useful in the association of chemotherapy with specific inhibitors of the enzyme in future studies.
Assuntos
Animais , Humanos , Trypanosoma/enzimologia , Tripanossomíase/enzimologia , Adenosina Desaminase/metabolismo , Trypanosoma/isolamento & purificação , Adenosina/metabolismo , Adenosina Desaminase/sangue , Mediadores da Inflamação/metabolismo , Modelos Animais de DoençasRESUMO
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
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
The aim of this study was to evaluate the nitric oxide (NO()) level, protein oxidation and antioxidant enzymes in rats infected with Trypanosoma evansi and establish the association of NO() levels with the degree of parasitemia. Thirty-six male rats (Wistar) were divided into two groups with 18 animals each. Group A was not infected while Group B was intraperitoneally infected, receiving 7.5×10(6) trypomastigotes per animal. Each group was divided into three subgroups with 6 rats each and blood was collected during different periods post-infection (PI), as follows: day 5 (A(5) and B(5)), day 15 (A(15) and B(15)) and day 30 PI (A(30) and B(30)). Blood samples were collected by cardiac puncture to estimate the levels of nitrites/nitrates (NO(x)) and advanced oxidation protein products (AOPP) in serum, and superoxide dismutase (SOD) and catalase (CAT) activities in blood. On days 15 and 30 PI NO(x) and AOPP levels were increased in serum of rats infected. Rodents infected with T. evansi showed a significant increase in SOD (days 5 and 15 PI) and CAT (day 30 PI) activities. Based on the physiological role of NO(), we can conclude that its increased concentration is related to an inflammatory response against the parasite, once a redox imbalance was observed during infection.
Assuntos
Catalase/metabolismo , Óxido Nítrico/metabolismo , Proteínas/metabolismo , Superóxido Dismutase/metabolismo , Tripanossomíase/metabolismo , Produtos da Oxidação Avançada de Proteínas/análise , Animais , Masculino , Óxido Nítrico/sangue , Oxirredução , Parasitemia/enzimologia , Parasitemia/metabolismo , Ratos , Ratos Wistar , Tripanossomíase/enzimologiaRESUMO
The aim of this study was to evaluate the activity of delta-aminolevulinate dehydratase (δ-ALA-D) in red blood cells of rats infected with Trypanosoma evansi and establish its association with haematocrit, serum levels of iron and zinc and lipid peroxidation. Thirty-six male rats (Wistar) were divided into 2 groups with 18 animals each. Group A was non-infected while Group B was intraperitoneally infected, receiving 7·5×106 trypomastigotes per animal. Each group was divided into 3 subgroups of 6 rats and blood was collected during different periods post-infection (p.i.) as follows: day 5 (A1 and B1), day 15 (A2 and B2) and day 30 PI (A3 and B3). Blood samples were collected by cardiac puncture to estimate red blood cell parameters (RBC), δ-ALA-D activity and serum levels of iron, zinc and thiobarbituric acid reactive substances (TBARS). Rats in group B showed a significant (P<0·05) reduction of RBC count, haemoglobin concentration and haematocrit at days 5 and 15 p.i. The activity of δ-ALA-D in blood was significantly (P<0·001) increased at days 15 and 30 p.i. δ-ALA-D activity in blood had a significant (P<0·05) negative correlation with haematocrit (r=-0·61) and haemoglobin (r=-0·70) at day 15 p.i. There was a significant (P<0·05) decrease in serum iron and zinc levels and an increase in TBARS levels (P<0·05) during infection. The δ-ALA-D activity in blood was negatively correlated with the levels of iron (r=-0·68) and zinc (r=-0·57) on day 30 p.i. It was concluded that the increased activity of δ-ALA-D in blood might have occurred in response to the anaemia in remission as heme synthesis was enhanced.
Assuntos
Anemia/enzimologia , Sintase do Porfobilinogênio/sangue , Trypanosoma/fisiologia , Tripanossomíase/enzimologia , Anemia/sangue , Anemia/complicações , Anemia/parasitologia , Animais , Contagem de Eritrócitos , Eritrócitos/química , Hematócrito , Hemoglobinas/análise , Ferro/análise , Peroxidação de Lipídeos , Masculino , Parasitemia/sangue , Ratos , Ratos Wistar , Espectrofotometria , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Tripanossomíase/sangue , Tripanossomíase/complicações , Tripanossomíase/parasitologia , Zinco/análiseRESUMO
The aim of this study was to evaluate Ca(2+) ATPase activity and the lipid peroxidation in muscles from rats experimentally infected by Trypanosoma evansi and its roles in the muscle pathogenesis in trypanosomosis. Thirty-six rats were divided in two groups. Group A was infected with an isolate from T. evansi and group B was used as a negative control. Group A was divided into three subgroups (A1, A2 and A3), three animals each group, as well as group B (B1, B2 and B3). The collection of samples were performed at days 5 (A1 and B1), 15 (A2 and B2) and 30 (A3 and B3) post-infection (PI) with the purpose of comparison between healthy and infected rats in the course of the disease. The Ca(2+) ATPase enzyme activity was determined in skeletal muscle samples. Muscle tissue lipid peroxidation was determined by TBARS levels, and histopathologically it was investigated a possible damage to the muscle tissue of rats infected with T. evansi. It was observed a significant decrease of Ca(2+) ATPase activity in infected rats compared to not-infected. This enzymatic inhibition was observed at days 5, 15 and 30 PI. A significant increase was observed for TBARS levels in the muscles of infected rats at days 5, 15 and 30 PI. It was not identified any histological alterations for gastrocnemius in rats infected by T. evansi at days 5 and 15 PI. Nevertheless, at day 30 PI it was verified inflammatory infiltrate with mononuclear cells between muscle fibers in three infected rats (50%). T. evansi infections in rats showed a negative correlation between Ca(2+) ATPase and TBARS levels. Based on these results we suggest that the leg weakness and muscle injuries common in infected animals with T. evansi may be related to a reduced activity of Ca(2+) ATPase and oxidative stress.
Assuntos
ATPases Transportadoras de Cálcio/metabolismo , Peroxidação de Lipídeos , Músculo Esquelético/metabolismo , Tripanossomíase/metabolismo , Animais , Estudos de Casos e Controles , Cães , Feminino , Músculo Esquelético/enzimologia , Músculo Esquelético/patologia , Parasitemia/enzimologia , Parasitemia/metabolismo , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Tripanossomíase/enzimologiaRESUMO
This study aimed to evaluate the activities of the ectoenzymes NTPDase and 5'-nucleotidase in synaptosomes from cerebral cortex of rats experimentally infected with Trypanosoma evansi. The animals were divided in four groups (n=10) according to the time and degree of parasitemia (groups A, B, C and D). The animals from group A were euthanized on day 3 (low parasitemia), group B on day 5 (high parasitemia) and group C on day 15 (low parasitemia). Group D consisted of healthy rats (not-infected, n=15) and were divided in three periods (n=5) in order to compare with the infected groups. After euthanasia, cerebral cortex was removed for the preparation of synaptosomes and enzymatic assays. Group A showed no changes in enzymatic activities compared with control. The hydrolysis of ATP, ADP and AMP by the enzymes NTPDase and 5'-nucleotidase were increased (P<0.05) in group B (38%, 140% and 61%, respectively) when compared with control. In the group C it was observed a decreased (22%) hydrolysis of ATP when compared with control group. The activities of NTPDase and 5'-nucleotidase in synaptosomes alters the acute phase of the disease when the number of circulating parasites is high, thus the change observed is probably due to the parasitemia.
Assuntos
5'-Nucleotidase/metabolismo , Nucleotídeos de Adenina/metabolismo , Córtex Cerebral/enzimologia , Pirofosfatases/metabolismo , Tripanossomíase/enzimologia , Animais , Córtex Cerebral/patologia , Cães , Masculino , Parasitemia/enzimologia , Parasitemia/parasitologia , Ratos , Sinaptossomos/enzimologia , Tripanossomíase/parasitologia , Tripanossomíase/patologiaRESUMO
In Trypanosoma evansi infections changes in the haemogram are commonly observed, and the enzyme adenosine deaminase (ADA) plays an important role in the production and differentiation of blood cells. Thus, the aim of this study was to evaluate the activity of ADA in serum, erythrocytes and lymphocytes of rats infected with T. evansi compared to non-infected rats. Thirty adult rats were used, divided into 3 uniform groups. The animals in groups A and B were infected intraperitoneally with 2 x 106 trypomastigotes/rat. Rodents from group C (control group), were not-infected. Blood collection was performed on days 4 and 20 post-infection (p.i.) in order to obtain acute and chronic infection stages of disease. The blood was used to assess the activity of ADA. In the blood, reduced haematocrit and increased lymphocytes were correlated with ADA activity in erythrocytes and lymphocytes. We observed reduction of ADA activity in serum and erythrocytes in rats infected with T. evansi compared to non-infected rats (P < 0.05). ADA activity in lymphocytes was decreased after 4 days, when the parasitaemia was high and increased after 20 days, when the number of circulating parasites was low. In conclusion, our results showed that the ADA activity was altered in serum, lymphocytes and erythrocytes of rats, concomitantly with haematological parameters, in experimental infection by T. evansi.
Assuntos
Adenosina Desaminase/sangue , Trypanosoma/enzimologia , Tripanossomíase/enzimologia , Animais , Contagem de Células , Eritrócitos/enzimologia , Hematócrito , Linfócitos/enzimologia , Masculino , Parasitemia/sangue , Parasitemia/enzimologia , Ratos , Soro/enzimologia , Tripanossomíase/sangueRESUMO
The study was undertaken to evaluate changes in the activity of adenosine deaminase (ADA) in brains of rats infected by Trypanosoma evansi. Each rat was intraperitoneally infected with 10(6) trypomastigotes either suspended in fresh (group A; n = 13) and cryopreserved blood (group B; n = 13). Thirteen animals were used as control (group C). ADA activity was estimated in the cerebellum, cerebral cortex, striatum and hippocampus. No differences (P > 0.05) in ADA activity were observed in the cerebellum between infected and non-infected animals. Significant (P < 0.05) reductions in ADA activity occurred in cerebral cortex in acutely (day 4 post-infection; PI) and chronically (day 20 PI) infected rats. ADA activity was significantly (P < 0.05) decreased in the hippocampus in acutely infected rats, but significantly (P < 0.05) increased in the chronically infected rats. Significant (P < 0.05) reductions in ADA activity occurred in the striatum of chronically infected rats. Parasites could be found in peripheral blood and brain tissue through microscopic examination and PCR assay, respectively, in acutely and chronically infected rats. The reduction of ADA activity in the brain was associated with high levels of parasitemia and anemia in acute infections. Alterations in ADA activity of the brain in T. evansi-infected rats may have implications for pathogenesis of the disease.
Assuntos
Adenosina Desaminase/metabolismo , Encéfalo/enzimologia , Trypanosoma/fisiologia , Tripanossomíase/enzimologia , Animais , Encéfalo/parasitologia , DNA de Protozoário/isolamento & purificação , Contagem de Eritrócitos , Hemoglobinas/análise , Contagem de Leucócitos , Masculino , Parasitemia/parasitologia , Reação em Cadeia da Polimerase , Ratos , Trypanosoma/genética , Trypanosoma/isolamento & purificação , Tripanossomíase/sangue , Tripanossomíase/parasitologiaRESUMO
The existence of cholinergic receptors in the immune system cells is well documented. This study aimed to evaluate the acetylcholinesterase activity (AChE) in lymphocytes from rats infected with Trypanosoma evansi in acute and chronic phase disease. Twenty animals were infected with 10(6) trypomastigotes forms each and 10 were used as negative controls. The two groups of inoculated rats were formed according to the degree of parasitemia and the period post-infection (PI). Group A: rats with 4 days PI and between 24 and 45 parasites/field (1000×); group B: rats with 30 days PI and parasitemia with jagged peaks between 0 and 1 parasites/field; group C: not-infected animals. At 4 days PI (acute phase) and 30 days PI (chronic phase) the rats were anesthetized to collect blood for hemogram and separation of lymphocytes. After separation, the AChE activity was measured in lymphocytes. It was observed that the number of lymphocytes increased significantly in group A compared to group C. The activity of AChE in lymphocytes significantly increased in acute phase and decreased in chronic phase in the infected rats when compared to not-infected (P<0.05). Statistical analysis showed a positive correlation between the number of lymphocytes and AChE activity in lymphocytes in 4 days PI (r(2): 0.59). Therefore, the infection by T. evansi influences AChE activity in lymphocytes of rats indicating changes in the responses of cholinergic system in acute phase, possibly due to immune functions performed by these enzymes.
Assuntos
Acetilcolinesterase/sangue , Linfócitos/enzimologia , Trypanosoma/imunologia , Tripanossomíase/enzimologia , Tripanossomíase/imunologia , Animais , Imunidade Celular , Contagem de Leucócitos , Linfócitos/citologia , Masculino , Parasitemia/enzimologia , Parasitemia/imunologia , Parasitemia/parasitologia , Ratos , Tripanossomíase/sangueRESUMO
The aim of this study was to evaluate cholinesterase activity during the early acute phase of Trypanosoma evansi infection in rats. Fifteen male Wistar rats were randomly distributed into three groups (n=5 animals per group): two trypanosome-infected groups (T3 and T5) and uninfected controls (C). The animals were inoculated intraperitoneally with 10(6) trypanosomes. The blood was collected by cardiac puncture on the 3rd (T3) or 5th day post-infection (T5 and C). Cerebrum and cerebellum were removed for the evaluation of acetylcholinesterase (AChE) activity. AChE activity was also evaluated in whole blood and butyrylcholinesterase activity (BUChE) in plasma samples. Parasitemia were progressive increase and parasites were observed in the peripheral blood of all infected animals one day post-inoculation. AChE activity was not altered in cerebrum and cerebellum tissues. AChE activity in blood significantly decreased in the T3 and T5 groups (26.63 and 25.86mU/lmolHb) compared with the control (37.84mU/lmolHb). In addition BUChE activity in plasma was lower in the T3 (7.01micromol BTC hydrolyzed/h/mL) than the T5 and C groups (9.84 and 12.00micromol BTC hydrolyzed/h/mL). This study therefore, shows that reductions in the activity of cholinesterase occur in acute infection by T. evansi in rats and this demonstrates an important change occurring in animals infected by the protozoan and may indicate a potential role the enzymes play in the mechanism of disease.
Assuntos
Acetilcolinesterase/metabolismo , Infecções Protozoárias do Sistema Nervoso Central/enzimologia , Trypanosoma/enzimologia , Tripanossomíase/enzimologia , Acetilcolinesterase/sangue , Doença Aguda , Análise de Variância , Animais , Butirilcolinesterase/sangue , Infecções Protozoárias do Sistema Nervoso Central/parasitologia , Cerebelo/enzimologia , Cérebro/enzimologia , Modelos Animais de Doenças , Masculino , Parasitemia/enzimologia , Parasitemia/parasitologia , Distribuição Aleatória , Ratos , Ratos Wistar , Tripanossomíase/sangue , Tripanossomíase/parasitologiaRESUMO
Changes in blood, plasma and brain cholinesterase activities in Trypanosoma evansi-infected cats were investigated. Seven animals were infected with 10(8) trypomastigote forms each and six were used as control. Animals were monitored for 56 days by examining daily blood smears. Blood samples were collected at days 28 and 56 post-inoculation to determine the activity of acetylcholinesterase (AChE) in blood and the activity of butyrylcholinesterase (BChE) in plasma. AChE was also evaluated in total brain. The activity of AChE in blood and brain, and the activity of BChE in plasma significantly reduced in the infected cats. Therefore, the infection by T. evansi influenced cholinesterases of felines indicating changes in the responses of the cholinergic system.
Assuntos
Acetilcolinesterase/metabolismo , Encéfalo/enzimologia , Doenças do Gato/enzimologia , Trypanosoma/isolamento & purificação , Tripanossomíase/veterinária , Animais , Doenças do Gato/sangue , Doenças do Gato/parasitologia , Gatos , Feminino , Tripanossomíase/sangue , Tripanossomíase/enzimologiaRESUMO
Protease activities in the haemolymph and fat body in a bloodsucking insect, Rhodnius prolixus, infected with Trypanosoma rangeli, were investigated. After SDS-polyacrylamide gel electrophoresis containing gelatin as substrate, analysis of zymograms performed on samples of different tissues of controls and insects inoculated or orally infected with short or long epimastigotes of T. rangeli, demonstrated distinct patterns of protease activities: (i) proteases were detected in the haemolymph of insects which were fed on, or inoculated with, short epimastigotes of T. rangeli (39 kDa and 33 kDa, respectively), but they were not observed in the fat body taken from these insects; (ii) protease was also presented in the fat bodies derived from naive insects or controls inoculated with sterile phosphate-saline buffer (49 kDa), but it was not detected in the haemolymph of these insects; (iii) no protease activity was observed in both haemolymph and fat bodies taken from insects inoculated with, or fed on, long epimastigotes of T. rangeli. Furthermore, in short epimastigotes of T. rangeli extracts, three bands of the protease activities with apparent molecular weights of 297, 198 and 95 kDa were detected while long epimastigotes preparation presented only two bands of protease activities with molecular weights of 297 and 198 kDa. The proteases from the insect infected with T. rangeli and controls belong to the class of either metalloproteases or metal-activated enzymes since they are inhibited by 1,10-phenanthroline. The significance of these proteases in the insects infected with short epimastigotes of T. rangeli is discussed in relation to the success of the establishment of infection of these parasites in its vector, R. prolixus.