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Cássia Bagolin da Silva, Patrícia Wolkmer,
Francine Chimelo Paim,
Aleksandro Schafer Da Silva,
Lucas Carvalho Siqueira,
Camila Lopes de Souza,
Raqueli Teresinha França,
Guilherme Lopes Dornelles,
Marta Maria Medeiros Frescura Duarte,
Silvia Gonzalez Monteiro,
Cinthia Melazzo Mazzanti,
Sonia Teresinha Dos Anjos Lopes
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ABSTRACT: The aim of this study was to evaluate biochemical parameters of iron metabolism in rats experimentally infected with T. evansi. To this end, 20 rats (Wistar) were intraperitoneally inoculated with blood containing trypomastigotes 10(6) (Group T) and 12 animals were used as negative control (Group C) and received saline (0.2 mL) through same route. Blood samples were collected by cardiac puncture on day 5 (C5, T5) and 30 (C30, T30) post-inoculation (pi) to perform complete blood count and determination of serum iron, transferrin, ferritin, total and latent iron fixation capacity, transferrin saturation and prohepcidin concentration. Also, bone marrow samples were collected, to perform Pearls staining reaction. Levels of iron, total and latent iron binding capacity and prohepcidin concentration were lower (P <0.05) in infected rats (T5 and T30 groups) compared to controls. On the other hand, levels of transferrin and ferritin were higher when compared to controls (P <0.05). The transferrin saturation increased on day 5 pi, but decreased on day 30 pi. The Pearls reaction showed a higher accumulation of iron in the bone marrow of infected animals in day 5 pi (P <0.01). Infection with T. evansi in rats caused anemia and changes in iron metabolism associated to the peaks of parasitemia. These results suggest that changes in iron metabolism may be related to the host immune response to infection and anemic status of infected animals.
Experimental Parasitology 12/2012; · 2.12 Impact Factor
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Patrícia Wolkmer,
Cássia B da Silva,
Francine C Paim,
Marta M M F Duarte,
Verônica Castro,
Heloisa E Palma,
Raqueli T França,
Diandra V Felin,
Lucas C Siqueira,
Sonia T A Lopes,
Maria Rosa C Schetinger,
Silvia G Monteiro,
Cinthia M Mazzanti
[show abstract]
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ABSTRACT: 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 60 mg/kg as preventive treatment (30 and 15 days 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.
Parasitology International 11/2012; · 2.13 Impact Factor
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Patrícia Wolkmer,
Cássia B da Silva,
Francine C Paim,
Aleksandro S Da Silva,
Kaio C S Tavares,
Cícera R Lazzarotto,
Heloisa E Palma,
Gustavo R Thomé,
Luiz C Miletti,
Maria Rosa C Schetinger,
Sonia T A Lopes,
Cinthia M Mazzanti
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ABSTRACT: 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 1.2mg/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 2.70μmol 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.
Experimental Parasitology 09/2012; · 2.12 Impact Factor
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ABSTRACT: The aim of this study was to investigate the changes in the levels of liver enzymes and urea associated with an outbreak of
cysticercosis (Taenia taeniformis) in rat liver. At the end of a previous trial, the animals were euthanized and necropsied when cysts of T. taeniformis were found. The number of cysts ranged from ten to 30 per rat liver. Blood samples were collected from ten rats with cysticercoids
(from 12 to 22 cysts) and from ten non-affected rats that were kept in another animal house. Alanine aminotransferase (ALT),
aspartate aminotransferase (AST), and urea values were reduced when compared with non-parasitized animals; alkaline phosphatase
(ALP) and gamma-glutamyltransferase (GGT) values were increased. Since the current experiment had to be repeated due to hepatic
impairment evidenced by reduced ALT, AST, and urea values and increased ALP and GGT values, this study aims to alert the scientific
community to the importance of sanitary barriers in animal housing.
Keywords
Cysticercus fasciolaris
-Rodents-Liver
Comparative Clinical Pathology 05/2012; 19(5):527-529.
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ABSTRACT: One of the main characteristics of the trypanosomosis is the development of anemia, although its pathogenesis still remains
unclear. Therefore, the objective of this study was to discuss the possible pathogenesis of anemia in the infection by Trypanosoma evansi in cats. A study using an experimental model with T. evansi-infected cats reported changes in serum iron levels, alterations in the activity of enzymes of the cholinergic system, and
oxidative stress correlated to normocytic, normochromic, and regenerative anemia. During this article, the aforementioned
parameters will be simultaneously analyzed and related to hematological parameters that determine anemia in cats infected
with this protozoan.
KeywordsAcetylcholinesterase–Anemia–Iron–Lipid peroxidation
Comparative Clinical Pathology 04/2012; 20(4):393-396.
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ABSTRACT: The aims of this study were to evaluate clotting disturbances in the acute infection by Trypanosoma evansi in rats and to investigate two possible causes. To address this issue, 21 2-month-old male rats were separated into three
groups with seven animals each. The control group (group I) was composed of non-infected animals and group II was composed
of 14 T. evansi-infected animals. This group was subdivided into two homogeneous groups. Animals from group II-a and from group II-b were
euthanized at days 3 and 5 post-inoculation (PI), respectively. Hematological parameters were evaluated for monitoring of
the disease. Infected animals showed anemia and leukocytosis 3days PI and a significant decrease was observed in platelet
count at days 3 and 5 PI. The prothrombin time (PT) and activated partial thromboplastin time (aPTT) were longer in the infected
groups. The averages of the megakaryocyte count significantly increased (P < 0.05) in group II-b (5days PI). Splenomegaly was observed in all T. evansi-infected rats at necropsy. Based upon the results, it is concluded that the acute infection by T. evansi in rats causes thrombocytopenia and longer prothrombin and activated partial thromboplastin times. In response to the thrombocytopenia,
an increased number of bone marrow megakaryocytes were observed in the infected rats. Thus, the decrease in circulating platelets
may be a consequence of splenic sequestration.
KeywordsTrypanosomosis–Platelets–Megakaryocytes–Prothrombin time–Activated partial thromboplastin time
Comparative Clinical Pathology 04/2012; 20(2):151-154.
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ABSTRACT: Coagulopathy in cats (Felis catus) parasitized by Trypanosoma evansi in both the initial and chronic phases of the disease has been investigated. To address this issue, seven animals were infected
with 108 trypomastigote forms each, and six were used as control. Animals were monitored for 56days by examining daily blood smears.
Blood samples for hematocrit, platelet counting, and fibrinogen levels were collect at 15-day intervals. Prothrombin time,
activated partial thromboplastin time, and number of megakaryocytes were analyzed at days 14 and 42 post-inoculation. A decrease
in hematocrit values and platelet counts and an increase in plasmatic fibrinogen concentration were observed in the infected
cats (P < 0.05). Coagulation time did not differ between the infected and non-infected groups. The reduction in platelet count increased
the number of megakaryocytes in the infected group (P < 0.05). These results indicate that the infection by T. evansi in cats increased the number of megakaryocytes in response to primary clotting disorders.
Keywords
Trypanosoma evansi
-Coagulopathies-Cats
Comparative Clinical Pathology 04/2012; 19(2):207-210.
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ABSTRACT: The aim of this study was to evaluate clinical signs of cats experimentally infected with Trypanosoma evansi. Thirteen adult female nonbreeding Felix catus were separated into two groups: seven animals were infected with 108 trypomastigotes each, and six animals were used as negative controls. Blood smears were performed daily for 56days. Cardiorespiratory
frequency was observed weekly, and blood samples for hematocrit analyses were collected at 15-day intervals. The protozoan
was found in the blood 24 to 48 hours post-inoculation and irregular peaks of parasitemia were observed. Hematocrit significantly
decreased in the infected group 7days post-inoculation. Moreover, we observed the same clinical signs in this study that
had previously been reported in other species commonly infected by T. evansi, including hyperthermia, lymphadenopathy, cachexia, and generalized edema. Based on these results, we conclude that domestic
cats are susceptible to T. evansi infection, showing severe clinical alterations and mortality due to the chronic evolution of the disease.
Comparative Clinical Pathology 04/2012; 19(1):85-89.
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Verônica S P Castro,
Victor C Pimentel,
Aleksandro S Da Silva,
Gustavo R Thomé, Patrícia Wolkmer,
Jorge L C Castro,
Márcio M Costa,
Cássia B da Silva,
Daniele C Oliveira,
Sydney H Alves,
Maria R C Schetinger,
Sonia T A Lopes,
Cinthia M Mazzanti
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ABSTRACT: 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.
Mycopathologia 12/2011; 174(1):31-9. · 1.65 Impact Factor
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Cássia B da Silva, Patrícia Wolkmer,
Aleksandro S Da Silva,
Francine C Paim,
Alexandre A Tonin,
Verônica S P Castro,
Diandra V Felin,
Roberta Schmatz,
Jamile F Gonçalves,
Manoel R T Badke,
Vera M Morsch,
Cinthia M Mazzanti,
Sonia T A Lopes
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ABSTRACT: 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.
Journal of Medical Microbiology 09/2011; 61(Pt 2):278-84. · 2.50 Impact Factor
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Raqueli T França,
Aleksandro S Da Silva, Patrícia Wolkmer,
Vitor A Oliveira,
Maria E Pereira,
Marta L R Leal,
Cássia B Silva,
Matheus A G Nunes,
Valderi L Dressler,
Cinthia M Mazzanti,
Silvia G Monteiro,
Sonia T A Lopes
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ABSTRACT: 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.
Parasitology 09/2011; 138(10):1272-7. · 2.96 Impact Factor
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Francine C Paim,
Aleksandro S Da Silva, Patrícia Wolkmer,
Márcio M Costa,
Cássia B Da Silva,
Carlos B V Paim,
Mauro S Oliveira,
Luiz F A Silva,
Carlos F Mello,
Silvia G Monteiro,
Cinthia M A Mazzanti,
Sonia T A Lopes
[show abstract]
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ABSTRACT: Nitric oxide (NO) is involved in many physiological processes, such as blood pressure control, neurotransmission, inhibition of platelet and neutrophil adherence, and the ability to kill tumor cells and parasites. The indirect determination of NO can be made by detection of 3-nitrotyrosine (3-NT) residues. The aim of this study was to measure the concentration of 3-NT in the brain of rats experimentally infected with Trypanosoma evansi. Twenty-four were inoculated intraperitoneally with cryopreserved blood containing 1×10(6) trypomastigotes per animal. Twenty-four animals were used as negative controls and received 0.2 mL of saline by the same route. The experimental groups (group C and T) were established according to the time after infection and the degree of parasitemia as follows: four control subgroups (C3, C5, C10 and C20) with six non-inoculated animals each and four test subgroups (T3, T5, T10 and T20) with six animals infected with T. evansi in each group. The animals were anesthetized with isoflurane and subsequently euthanized at the days 3 (C3, T3), 5 (C5, T5), 10 (C10, T10) and 20 (C20, T20) post-infection (PI). The brain was removed and dissected into cerebellum, cerebral cortex, striatum and hippocampus. Concentration of 3-NT in the brain was determined by Slot blot technique. At the day 3 PI no changes were observed in the concentration of 3-NT among the groups. There was a significant reduction (p<0.05) of 3-NT concentration in the striatum and cerebellum at the days 5 and 10 PI, respectively. At the day 20 PI a significant increase (p<0.05) of 3-NT was observed in the cerebellum, cerebral cortex and hippocampus from the infected animals. Therefore, T. evansi infection caused changes in the concentrations of 3-NT in the central nervous system (CNS), which may be related to clinical signs and infection management.
Experimental Parasitology 06/2011; 129(1):27-30. · 2.12 Impact Factor
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Aleksandro S Da Silva, Patrícia Wolkmer,
Joao T S Nunes,
Marcos R K Duck,
Camila B Oliveira,
Lucas T Gressler,
Marcio M Costa,
Régis A Zanette,
Cinthia M Mazzanti,
Sonia T A Lopes,
Silvia G Monteiro
[show abstract]
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ABSTRACT: Drugs, which are effective during the early stage of trypanosomosis, but poorly penetrate the blood-brain barrier, are ineffective when parasites reach the brain and cause encephalitis. In order to seek alternative treatments, the aim of this study was to test the susceptibility of T. evansi to cordycepin in vitro and in rats experimentally infected. In vitro, a significant decrease (P<0.01) in live trypanosomes in the concentrations of 5.0 and 10 μg/mL was observed 1 hour after the beginning of the study, as well as at 3, 6, 9 and 12 hours in all concentrations compared to control. Although no curative effects were observed in the in vivo assay in the majority of groups, the drug was able to maintain parasitemia at low levels, therefore increasing the longevity of rats when compared to positive control group. Rats that received cordycepin alone or in combination with adenosine deaminase inhibitor (ADA: EHNA hydrochloride), did not show trypomastigote forms of the parasite in the bloodstream 24 hours after the administration. These animals remained negative in blood smears on average for 8 days, but thereafter had a recurrence of parasitemia. Among all the infected animals, only three rats in the group treated with the combination of cordycepin (2 mg/kg) and EHNA hydrochloride (2 mg/kg) remained negative during the experimental period. The curative efficacy of 42.5% was confirmed by PCR using T. evansi-specific primers. Thus, we conclude that cordycepin has biological effect against T. evansi, as previously reported in infections by T. brucei, T. cruzi and Leishmania sp. The treatment with cordycepin, when protected by an inhibitor of ADA, can prolong the survival of T. evansi-infected rats and provide curative efficacy.
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 05/2011; 65(3):220-3. · 2.24 Impact Factor
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Francine C Paim,
Marta M M F Duarte,
Márcio M Costa,
Aleksandro S Da Silva, Patrícia Wolkmer,
Cássia B Silva,
Carlos B V Paim,
Raqueli T França,
Cinthia M A Mazzanti,
Silvia G Monteiro,
Alexandre Krause,
Sonia T A Lopes
[show abstract]
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ABSTRACT: The aim of this study was to measure the levels of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin 1 (IL-1) and interleukin 6 (IL-6) in the serum of rats experimentally infected with Trypanosoma evansi and to correlate these levels with hematological parameters. Initially, 48 rats (group T) were intraperitoneally inoculated with cryopreserved blood containing 1×10(6) trypomastigotes per animal. Twenty-eight animals (group C) were used as negative controls and received 0.2 mL of saline by the same route. The experimental groups were formed according to the time after infection and the degree of parasitemia as follows: four control subgroups (C3, C5, C10 and C20) with seven non-inoculated animals each and four test subgroups (T3, T5, T10 and T20) with 10 animals each inoculated with T. evansi. The blood samples were collected by cardiac puncture at days 3 (C3, T3), 5 (C5, T5), 10 (C10, T10) and 20 (C20, T20) post-infection (PI) to perform the complete blood count and the determination of IFN-γ, TNF-α, IL-1 and IL-6 levels using an ELISA quantitative sandwich. Infected rats showed normocytic normochromic anemia during the experimental period. T. evansi infection in rats caused a serum increase (P<0.01) of IFN-γ, TNF-α, IL-1 and IL-6 levels at days 3, 5, 10 and 20 PI compared to the controls. The multiple linear regressions showed a reduction of 24% in the hematocrit as a consequence of the increased IFN-γ, TNF-α and IL-1. Therefore, we conclude that the infection caused by T. evansi causes an increase in the pro-inflammatory cytokines. These results suggest a synergism among IL-1, TNF-α and IFN-γ contributing to the development of anemia. This increase is associated with the regulation of immune responses against the parasite.
Experimental Parasitology 05/2011; 128(4):365-70. · 2.12 Impact Factor
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Aleksandro S Da Silva,
Victor C Pimentel,
Jeandre A S Jaques, Patrícia Wolkmer,
Kaio C S Tavares,
Cícera R Lazzarotto,
Luiz C Miletti,
Maria Rosa C Schetinger,
Cinthia M Mazzanti,
Sonia T A Lopes,
Silvia G Monteiro
[show abstract]
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ABSTRACT: Biochemical and molecular research on parasites has increased considerably in trypanosomes in the recent years. Many of them have the purpose of identify areas, proteins and structures of the parasite which are vulnerable and could be used in therapy against the protozoan. Based on this hypothesis this study aimed to detect biochemically the enzyme adenosine deaminase (ADA) in Trypanosoma evansi, and to adapt an assay to the measurement of its activity in trypomastigotes. Firstly, the parasites were separated from the blood of mice experimentally infected with a DEAE-cellulose column. The ADA activity in trypomastigotes was evaluated at concentrations of 0.1, 0.2, 0.5, 0.6 and 0.8mg of protein by spectrophotometry. ADA activity was observed in the parasites at all concentrations tested and its activity was proportional to the concentration of protein, ranging between 0.64 and 2.24U/L in the lowest and highest concentration of protein, respectively. Therefore, it is possible to detect biochemically ADA in T. evansi, an enzyme that may be associated with vital functions of the parasite, similar to what occurs in mammals. This knowledge may be useful in the association of the chemotherapic treatment with specific inhibitors of the enzyme, in future studies.
Experimental Parasitology 03/2011; 128(3):298-300. · 2.12 Impact Factor
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Alexandre A Tonin,
Victor C Pimentel,
Aleksandro S da Silva,
Maria Isabel de Azevedo,
Viviane C G Souza, Patrícia Wolkmer,
João F P Rezer,
Manoel R T Badke,
Daniela B R Leal,
Maria Rosa C Schetinger,
Silvia G Monteiro,
Sonia T A Lopes
[show abstract]
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ABSTRACT: Leptospirosis is a systemic disease of humans and domestic animals, mainly dogs, cattle and swine. The course of human leptospirosis varies from mild to severe fatal forms and the most severe form of human leptospirosis is principally caused by Leptospira interrogans serovar icterohaemorrhagiae (L. icterohaemorrhagiae). The enzyme adenosine deaminase (ADA) plays an important role in the production and differentiation of blood cells. The aim of this study was to evaluate the activity of ADA in serum, erythrocytes and lymphocytes of rats infected with L. icterohaemorrhagiae, as compared with non-infected rats. Twenty-four adult rats, divided into two uniform groups (A and B) were used for the enzymatic assays. The animals in Group B were inoculated intraperitoneally with 2×10(8) leptospires/rat, and the rodents in Group A (control) were not-inoculated. Blood collection was performed on days 5 and 15 post-infection (PI) and the blood used to assess the ADA activity. The infection by L.icterohaemorrhagiae altered erythrocyte count, hemoglobin concentration and hematocrit, causing a decrease in all these parameters on day 15 PI. Lymphocytes decreased significantly on day 15 PI, and ADA activity in serum was inhibited in infected rats on days 5 and 15 PI and its activity in erythrocytes were increased on day 5 PI. On day 5 PI, we found an increase in ADA activity in erythrocytes of infected rats. No correlation was observed between hematocrit and erythrocyte ADA activity on days 5 and 15 PI. The ADA activity was inhibited in rats infected on day 15 PI. A positive correlation (r(2)=60) was also observed between the number of lymphocytes and ADA activity in lymphocytes on day 15 PI (P<0.05). In conclusion, our results showed that the ADA activity is altered in serum, lymphocytes and erythrocytes in experimental infection by L.icterohaemorrhagiae in rats, concomitantly with hematological parameters.
Research in Veterinary Science 02/2011; 92(2):197-201. · 1.65 Impact Factor
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ABSTRACT: This study was aimed at evaluating the electrophoretic profile of serum proteins in Trypanosoma evansi-infected cats during different periods of infection. Thirteen adult females non-breeding Felis catus were separated into two groups. Animals from the infected group (n=7) were inoculated intraperitoneally with a strain of T. evansi; whereas, animals from the control group (n=6) received a physiological solution. Blood samples were collected at days 0, 7, 21, and 35 for total protein evaluation and protein fractionation by electrophoresis. Albumin (P<0.01), alpha-2 globulin and gamma globulin (P<0.05) concentrations were statistically different from the seventh day post-inoculation onwards. Beta-globulin levels were increased from day 21 onwards (P<0.05). Alpha-1 globulin fraction did not differ statistically. These results indicate that the infection by T. evansi in cats alters the serum protein electrophoretic profile.
Preventive Veterinary Medicine 05/2010; 95(3-4):301-4. · 2.05 Impact Factor
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ABSTRACT: 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.
Experimental Parasitology 02/2010; 125(3):251-5. · 2.12 Impact Factor
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ABSTRACT: The objective of this study was to evaluate the lipid peroxidation and the susceptibility of erythrocytes to in vitro peroxidation as indicators of oxidative damage in erythrocytes and their roles in the pathogenesis of anemia during experimental Trypanosoma evansi infection in cats. Animals were divided into two groups: control and infected with T. evansi. Seven cats were infected with 10(8) trypomastigotes each, and parasitemia was estimated daily for 49 days by microscopic examination of smears. Hematological and biochemical parameters were evaluated for monitoring of the disease. Plasma lipid peroxidation (Thiobarbituric Acid Reactive Substances (TBARS)) and the susceptibility of erythrocytes to in vitro peroxidation were evaluated. Blood samples for analysis were collected at days 21 and 49 post-inoculation. TBARS level, indicated by MDA concentration, was higher in the infected group than in the control group in both analyzed periods, as well as the in vitro erythrocyte peroxidation (P < 0.001). The infected cats had variable degrees of regenerative anemia, which could be explained by the damage in erythrocyte membrane caused by lipid peroxidation.
Parasitology Research 09/2009; 106(1):157-61. · 2.15 Impact Factor
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ABSTRACT: This study aimed to assess the plasma lipid peroxidation and the susceptibility of erythrocytes to in vitro peroxidation as indicators of oxidative damage in erythrocytes and their roles in the pathogenesis of anemia during the early acute phase of Trypanosoma evansi infection in rats. Fifty male Wistar rats were randomly distributed into seven groups: three trypanosome-infected groups (T(2), T(4) and T(6); n=10 animals per group) and four uninfected controls (C(0), C(2), C(4) and C(6); n=5 animals per group). Animals from trypanosome-infected groups were inoculated intraperitoneally with 10(6) trypanosomes. Blood samples were collected by cardiac puncture before infection (day 0; group C(0)) or on the 2nd (C(2) and T(2)), 4th (C(4) and T(4)) and 6th (C(6) and T(6)) day post-infection (dpi). Samples were analyzed for red blood cell (RBC) count, hemoglobin (Hb) concentration, packed cell volume (PCV), plasma malondialdehyde (MDA) and in vitro peroxidation of erythrocytes. The mean values of the hematological indices gradually decreased in the infected rats compared with the control. MDA was significantly increased (P<0.001) on the 6th dpi in infected versus control animals and was negatively correlated with PCV (P<0.001; R(2)=0.372). The values for erythrocyte in vitro peroxidation were higher for groups T(4) and T(6) than for the control rats (P<0.01). A positive correlation between erythrocyte peroxidation and MDA (P<0.001; R(2)=0.414) was observed. The results of this study indicate that T. evansi infection in rats is associated with oxidative stress, indicated by lipid peroxidation and oxidative damage in erythrocyte membranes, as demonstrated by in vitro peroxidation. This may be one of the causes of anemia in acute trypanosomosis.
Veterinary Parasitology 08/2009; 165(1-2):41-6. · 2.58 Impact Factor
