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Platelet aggregation and adenosine deaminase (ADA) activity were evaluated in pregnant women living with some disease conditions including hypertension, diabetes mellitus and human immunodeficiency virus infection. The subject population is consisted of 15 non-pregnant healthy women [control group (CG)], 15 women with normal pregnancy (NP), 7 women with hypertensive pregnancy (HP), 10 women with gestational diabetes mellitus (GDM) and 12 women with human immunodeficiency virus-infected pregnancy (HIP) groups. The aggregation of platelets was checked using an optical aggregometer, and serum ADA activity was determined using the colorimetric method. After the addition of 5 µM of agonist adenosine diphosphate, the percentage of platelet aggregation was significantly (p < 0·05) increased in NP, HP, GDM and HIP groups when compared with the CG, while the addition of 10 µM of the same agonist caused significant (p < 0·05) elevations in HP, GDM and HIP groups when compared with CG. Furthermore, ADA activity was significantly (p < 0·05) enhanced in NP, HP, GDM and HIP groups when compared with CG. In this study, the increased platelet aggregation and ADA activity in pregnancy and pregnancy-associated diseases suggest that platelet aggregation and ADA activity could serve as peripheral markers for the development of effective therapy in the maintenance of homeostasis and some inflammatory process in these pathophysiological conditions. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Unlabelled: The effect of vitamin D3 in oral solution (VD3 ) and vitamin D3 -loaded nanocapsules (NC-VD3 ) was analysed in animals with complete Freund's adjuvant (CFA) induced arthritis (AR). For this purpose, we evaluated scores for arthritis, thermal hyperalgesia and paw oedema, as well as histological analyses and measurements of the activity of the ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) and ecto-adenosine deaminase (E-ADA) enzymes in rat lymphocytes. Haematological and biochemical parameters were also determined. The doses administered were 120 UI/day of VD3 and 15.84 UI/day of NC-VD3 . Fifteen days after the induction of AR, the groups were treated for 15 days with vitamin D3 . The results demonstrated that VD3 was able to reduce arthritis scores, thermal hyperalgesia and paw oedema in rats with CFA-induced arthritis. However, treatment with NC-VD3 did not reduce arthritis scores. The histological analyses showed that both formulations were able to reduce the inflammatory changes induced by CFA. The activity of E-NTPDase in rat lymphocytes was higher in the AR compared with the control group, while the activity of E-ADA was lower. This effect was reversed after the 15-day treatment. Data from this study indicates that both forms of vitamin D3 seem to contribute to decreasing the inflammatory process induced by CFA, possibly altering the activities of ectoenzymes. Copyright © 2016 John Wiley & Sons, Ltd., Significance of the Study: The effects promoted by both formulations of vitamin D3 , either in oral solution or nanoencapsulated form, strongly suggests the softening of the inflammatory process induced by complete Freund's adjuvant (CFA), possibly altering the E-NTPDase and E-ADA activities. However, it is known that vitamin D has a beneficial effect on the modulation of the immune system components responsible for the inflammatory process. Moreover, the establishment of responses to treatment with vitamin D3 may provide an alternative for inhibiting the proinflammatory response, assisting in our understanding of the immunopathology of this disease and possibly improving the signs and symptoms that hinder the quality of life of patients with rheumatoid arthritis., Highlights: Evaluation of the effects on the E-NTPDase and E-ADA activities in an animal model of induced arthritis. Two formulations of vitamin D3 were used: form oral solution and nanoencapsulated. Vitamin D3 seems to contribute to the inflammatory process induced by CFA. Vitamin D3 possibly alters the E-NTPDase and E-ADA activities. Vitamin D3 may be an alternative supplementary treatment for chronic arthritis., (Copyright © 2016 John Wiley & Sons, Ltd.)

Salmonella Gallinarum is the etiologic agent of fowl typhoid that affects chickens and turkeys causing egg production drops, infertility, lower hatchability, high mortality, and as a consequence severe economic losses to the poultry industry. The alterations in NTPDase and adenosine deaminase (ADA) activities have been demonstrated in several inflammatory conditions; however, there are no data in the literature associated with this infection. Thus, the aim of this study was to evaluate the activities of NTPDase, 5'nucleotidase, and ADA in serum and hepatic tissue of laying hens naturally infected by Salmonella Gallinarum. Liver and serum samples were collected of 27 laying hens (20 S. Gallinarum infected and 7 uninfected). NTPDase and 5'-nucleotidase activities in serum were increased (P < 0.001) in infected animals to hydrolysis of substrate ATP, ADP and AMP. In addition, it was observed decreased (P < 0.001) in ADA activity in serum of laying hens naturally infected by S. Gallinarum; as well as increased (P < 0.001) ADA activity in liver tissue of infected laying hens. Histopathological analyses revealed that S. Gallinarum caused fibrinoid necrosis in liver and spleen associated with infiltrates of heterophils, macrophages, lymphocytes, and plasma cells. Considering that NTPDase and ADA are involved in the cell-mediated immunity, this study suggests that activities of these enzymes could be important biomarkers to determine the severity of inflammatory and immune responses in salmonellosis, contributing to clarify the pathogenesis of the disease., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Sickle cell anemia (SCA) is a hemoglobinopathy characterized by hemolysis and vaso-occlusions caused by rigidly distorted red blood cells. Sickle cell crisis is associated with extracellular release of nucleotides and platelets, which are critical mediators of hemostasis participating actively in purinergic thromboregulatory enzymes system.This study aimed to investigate the activities of purinergic system ecto-enzymes present on the platelet surface as well as CD39 and CD73 expressions on platelets of SCA treated patients. Fifteen SCA treated patients and 30 health subjects (control group) were selected. Ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5'-nucleotidase (E-5'-NT) and ecto-adenosine deaminase (E-ADA) activities were measured in platelets isolated from these individuals. Results demonstrated an increase of 41 % in the E-NTPDase for ATP hydrolysis, 52% for ADP hydrolysis and 60 % in the E-ADA activity in SCA patients (P<0.05); however, a two folds decrease in the CD39 expression in platelets was observed in the same group (P<0.01). The increased E-NTPDase activity could be a compensatory mechanism associated with the low expression of CD39 in platelets. Besides, alteration of these enzymes activities suggests that the purinergic system could be involved in the thromboregulatory process in SCA patients., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Sickle cell anemia (SCA) is characterized by hemoglobin polymerization that results in sickle-shaped red blood cells. The vascular obstruction by sickle erythrocytes is often inflammatory, and purinergic system ecto-enzymes play an important role in modulating the inflammatory and immune response. This study aimed to evaluate the E-NTPDase and E-ADA activities in lymphocytes of SCA treated patients, as well as verify the cytokine profile in this population. Fifteen SCA treated patients and 30 health subjects (control group) were selected. The peripheral lymphocytes were isolated and E-NTPDase and E-ADA activities were determined. Serum was separated from clot formation for the cytokines quantification. E-NTPDase (ATP and ADP as substrate) and E-ADA (adenosine as substrate) activities were increased in lymphocytes from SCA patients (P<0.001). The TNF-α and IL-6 serum cytokines showed decreased on SCA patients comparing to control (P<0.001). The regulation of extracellular nucleotides released in response to hypoxia and inflammation through E-NTPDase and E-ADA enzymes represent an important control of purine-mediated in the SCA disease, avoiding elevated adenosine levels in the extracellular medium and consequent organ injuries in these patients. The pro-inflammatory cytokines decreased levels by use of hydroxyurea occur in attempt to reduce the pro-inflammatory response and prevent vaso-oclusive crisis., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Background and Method: Hypertension is accompanied by inflammatory process and purinergic system has been recognized as having an important role in modulating immune functions. Physical training is being considered one of the major lifestyle changes that contributes to the cardiovascular health as well as has an important role in regulating purinergic system. Thus, the aim of this study was to investigate the effect of chronic swimming training on lymphocytic purinergic system enzymes activities related to inflammatory process, as well as in lipid profile and classic inflammatory markers in rats that developed hypertension in response to the oral administration of N-nitro-L-arginine methyl ester hydrochloride (L-NAME)., Results: After 6 weeks of training, lymphocytes and serum were separated to be analysed. L-NAME-treated group displayed an increase in SBP as well as in ecto-NTPDase and adenosine deaminase (ADA) activities (P < 0.05). Six weeks of swimming training were able to prevent these alterations and keep the blood pressure and enzymes activities in the same levels of control group. Exercise per se was associated with a decrease in the expression of ecto-NTPDase1 in lymphocytes (-23.4%). Exercise was also efficient in preventing the rise in classic inflammatory markers observed in L-NAME group., Conclusion: These findings highlight the link between purinergic signalling and inflammatory process and suggest a novel mechanism in which moderate aerobic exercise possesses the potential to attenuate inflammation caused by hypertension.

Cryptococcus neoformans, the etiological agent of cryptococcosis, is an opportunistic fungal pathogen of immunocompromised individuals. The aim of this study was to evaluate the activities of E-NTPDase and E-ADA in rats experimentally infected by C. neoformans var. grubii. Adult rats (35) were divided in two groups: 18 for the control group (uninfected) (A), and 17 for the infected group (B). Each group was separated into three sub-groups (A1, A2, A3-B1, B2, B3), and samples were collected on 10, 20, and 30 days post-infection (PI). Leukocyte counts, IFN-γ, TNF-α, IgM, IgG levels, and E-NTPDase and E-ADA activities were analyzed. It was possible to observe that IgG and IgM seric levels of infected rats were significantly elevated (P<0.01) on days 10, 20 and 30 PI, as well as the levels of TNF-α and INF-γ when compared to uninfected rodents. Regarding E-NTPDase activity in lymphocytes, it was possible to observe that the ATP hydrolysis was significantly decreased on days 20 (P<0.01) and 30 PI (P<0.05), while ADP hydrolysis was significantly reduced only on day 20 PI (P<0.01) when compared with uninfected group. Seric E-ADA activity had a significant reduction (P<0.01) during all three evaluated periods when compared to the control group, while E-ADA activity in lymphocytes increased significantly (P<0.01) when compared to the group A on day 10 PI; however on days 20 and 30 PI, its activity was considerable reduced in lymphocytes of infected animals (P<0.01). Therefore, it is possible to conclude that the infection caused by C. neoformans in immunocompetent rats leads to changes in the purinergic signaling (NTPDase and E-ADA), concomitantly with an inflammatory response (increased levels of cytokines and immunoglobulins) associated with inflammatory infiltrates and histological lesions in the lung., (Copyright © 2014 Elsevier B.V. All rights reserved.)

This study aimed to verify the effect of 3'-deoxyadenosine and deoxycoformycin on hematologic parameters and adenosine deaminase (ADA) activity in plasma and brain of mice infected with Trypanosoma evansi. Seventy animals were divided into seven groups, which were divided into two subgroups each for sampling on days 4 and 8 post-infection (PI). The groups were composed of three uninfected groups (A-C), namely, not-treated (A), treated with 3'-deoxyadenosine (B), and treated with deoxycoformycin (C) and four infected groups, mice with T. evansi (D-G), namely, not-treated (D), treated with 3'-deoxyadenosine (E), treated with deoxycoformycin (F), and treated with a combination 3'-deoxyadenosine and deoxycoformycin (G). Hematological parameters and ADA activity were evaluated in plasma and brain. Animals in groups B and C exhibited a reduction in the levels of plasma total protein compared group A. Animals in groups D and F showed changes in the hematological parameters. The ADA activity significantly reduced in the animals of groups C, D, F and G. Mice in the group E presented increased ADA activity in plasma. Therefore, we conclude that the treatment interferes significantly in the hematologic parameters in mice infected with T. evansi. On the other hand, when the ADA inhibitor was used we observed a significant decrease in the values of hematocrit, total erythrocytes, and hemoglobin concentration. The deoxycoformycin was able to inhibit the ADA activity of parasite thus it may be one of the mechanisms of efficacy of this treatment., (Copyright © 2013 Elsevier Inc. All rights reserved.)

An investigation of E-NTPDase and E-ADA activities in lymphocytes from rats experimentally infected with Toxoplasma gondii was carried out in this study. For this purpose, twenty four adult male Wistar rats were divided in two groups/four subgroups (A1 and A2; B1 and B2-6 animal/each group), with "A" as uninfected and "B" inoculated with T. gondii (RH strain). Sampling was performed on days 5 and 10 post-infection (p.i.), with evaluation of hemogram, immunoglobulins (IgM and IgG) and activity of E-NTPDase and E-ADA in lymphocytes. Enzymes essays showed ATP hydrolysis increased on days 5 (P<0.05) and 10 (P<0.01) p.i., as well as an increase of ADP hydrolysis on day 10 (P<0.01) p.i. E-ADA activity on lymphocytes was also increased in both evaluated periods (P<0.01). Based on E-NTPDase and E-ADA increased activities observed on lymphocytes, it is possible to suggest their involvement in an anti-inflammatory response, consisting of a modulatory response, preventing excessive tissue damage caused by the infection with Toxoplasma gondii., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Piracetam improves cognitive function in animals and in human beings, but its mechanism of action is still not completely known. In the present study, we investigated whether enzymes involved in extracellular adenine nucleotide metabolism, adenosine triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase and adenosine deaminase (ADA) are affected by piracetam in the hippocampus and cerebral cortex of animals subjected to scopolamine-induced memory impairment. Piracetam (0.02 μmol/5 μL, intracerebroventricular, 60 min pre-training) prevented memory impairment induced by scopolamine (1 mg/kg, intraperitoneal, immediately post-training) in the inhibitory avoidance learning and in the object recognition task. Scopolamine reduced the activity of NTPDase in hippocampus (53 % for ATP and 53 % for ADP hydrolysis) and cerebral cortex (28 % for ATP hydrolysis). Scopolamine also decreased the activity of 5'-nucleotidase (43 %) and ADA (91 %) in hippocampus. The same effect was observed in the cerebral cortex for 5'-nucleotidase (38 %) and ADA (68 %) activities. Piracetam fully prevented scopolamine-induced memory impairment and decrease of NTPDase, 5'-nucleotidase and adenosine deaminase activities in synaptosomes from cerebral cortex and hippocampus. In vitro experiments show that piracetam and scopolamine did not alter enzymatic activity in cerebral cortex synaptosomes. Moreover, piracetam prevented scopolamine-induced increase of TBARS levels in hippocampus and cerebral cortex. These results suggest that piracetam-induced improvement of memory is associated with protection against oxidative stress and maintenance of NTPDase, 5'-nucleotidase and ADA activities, and suggest the purinergic system as a putative target of piracetam.

Pythiosis is a life-threatening disease caused by the oomycete Pythium insidiosum. Some authors have suggested the involvement of a Th2-like immune response in the infected host, which leads to extensive tissue damage. The switch from a Th2 to a Th1 response pattern is one hypothesis to explain the curative properties of immunotherapy. Taking into account the importance of immunotherapy for pythiosis treatment and the contribution of adenine nucleotides in the immunoregulation of the host, we evaluated the ecto-adenosine deaminase (E-ADA; EC 3·5.4·4) activity in lymphocytes from rabbits inoculated with P. insidiosum. Rabbits were inoculated with 1 milliliter of zoospores subcutaneously injected into the lateral thorax; after developing lesions, the rabbits received eight doses of immunotherapy. E-ADA activity was measured in lymphocytes and the adenine nucleotides and adenosine levels were quantitatively determined in serum. Rabbits with characteristic lesions of pythiosis showed a decreased E-ADA activity (82·36%), a decreased adenosine triphosphate concentration (54·04%) and a higher adenosine concentration (2·51 fold), when compared with controls, after 28 days of inoculation. However, after the immunotherapy, the rabbits showed an increase in the E-ADA activity when compared with control (78·62%), contributing for the change in the immune response. Our results reinforce the hypothesis that the change from a Th2 to a Th1 immune response with the participation of the purinergic system could be responsible for the curative properties of immunotherapy., (Copyright © 2012 John Wiley & Sons, Ltd.)

The purpose of this study was to investigate the activities of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase; EC 3.6.1.5; CD39) and adenosine deaminase (E-ADA; EC 3.5.4.4) in lymphocytes from patients with rheumatoid arthritis (RA). Thirty patients diagnosed with RA through American College of Rheumatology criteria as well as 30 healthy patients were selected. Peripheral blood lymphocytes were isolated, and E-NTPDase and E-ADA activities were assayed. The results demonstrated an increased E-NTPDase activity (both ATP and ADP as substrates) and a decreased E-ADA activity in RA patients. These data suggest an organic effort to preserve the adenosine level, which is known to have anti-inflammatory and analgesic properties, working as a potent suppressor of immune response., (Copyright © 2012 John Wiley & Sons, Ltd.)

Trypanosoma cruzi infection triggers a chronic inflammatory process in human host and purinergic system ecto-enzymes play an important role in modulating the inflammatory and immune responses. In this study, it was investigated ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase; EC 3.6.1.5; CD39) and ecto-adenosine deaminase (E-ADA; EC 3.5.4.4) activities in lymphocytes from patients with indeterminate form of Chagas' disease (IFCD). Twenty-five IFCD patients and 25 healthy subjects (control group) were selected. The peripheral lymphocytes were isolated and E-NTPDase and E-ADA activities were determined. Adenine nucleotides and adenosine levels were determined in serum by HPLC and the E-NTPDase1 expression in lymphocytes by Western blot analysis. E-NTPDase (ATP and ADP as substrates) and E-ADA (adenosine as substrate) activities were decreased in lymphocytes from IFCD patients (P<0.05 and P<0.01, respectively), while the E-NTPDase1 expression presented no changes in these patients. Serum ATP levels showed to be decreased (P<0.05) and both AMP (P<0.01) and adenosine (P<0.001) levels were increased in the IFCD group. The enzymatic alterations observed are in agreement with the immune response against T. cruzi infection in IFCD patients, since the decreased extracellular ATP and the increased adenosine levels trigger a Th2 anti-inflammatory response, which it is associated to adaptation of host to parasite, preventing clinical progress of disease., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Chagas disease (CD) is a chronic and endemic illness caused by the parasite Trypanosoma cruzi. Microvascular disturbances play an important role in the progress of the disease. The purinergic signaling system participates in regulatory functions, such as immunomodulation, neuroprotection, and thromboregulation. This study aimed to investigate the activities of purinergic system ecto-enzymes present on the platelet surface and the platelet aggregation profile from patients with indeterminate form of Chagas disease (IFCD). Thirty patients diagnosed with IFCD and 30 healthy subjects were selected. Ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-nucleotide pyrophosphatase/phosphodiesterase (E-NPP), ecto-5'-nucleotidase (E-5'-NT) and ecto-adenosine deaminase (E-ADA) activities were measured in platelets isolated from these individuals as well as the platelet aggregation. Results demonstrated an increase of 21 % in the E-NPP activity and 30 % in the E-5'-NT activity in IFCD group (P < 0.05); however, a decrease of 34 % in the E-ADA activity was determined in the same group (P < 0.001). A significant decrease of 12.7 % and 12.8 % in the platelet aggregation of IFCD group in two different concentrations of ADP (5 and 10 μM) was observed, respectively (P < 0.05). Increased E-NPP and E-5-NT activities as well as decreased E-ADA activity in platelets of patients with IFCD contributed to decrease platelet aggregation, suggesting that the purinergic system is involved in the thromboregulation process in these patients, since adenosine (the final product of ATP hydrolysis) has cardioprotective and vasodilator effects that prevent the clinical progress of the disease.

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., (Copyright © 2012 Elsevier Inc. All rights reserved.)

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., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The aim of the present study was to investigate the effect of curcumin (Cur) on the activity of ectonucleoside triphosphate diphosphohydrolase (CD39), 5'-nucleotidase (CD73) and adenosine deaminase in platelets of cigarette smoke-exposed rats. For that purpose, we subjected male Wistar rats to a treatment with Cur and cigarette smoke, once a day, 5 days each week, for 30 days. The rats were treated by gavage with Cur or corn oil and then exposed to cigarette smoke. The experimental procedures were divided into two sets of experiments. In the first, the animals were divided into four groups: vehicle (corn oil) or Cur 12·5, 25 or 50 mg·kg(-1) . In the second, the animals were divided into five groups: vehicle (corn oil), smoke, or smoke and Cur 12·5, 25 or 50 mg·kg(-1) . The results showed that treatment with Cur significantly prevented the increased adenosine triphosphate (ATP) (121%) and adenosine monophosphate (AMP) (159%) and the decreased adenosine diphosphate (ADP) (51%) hydrolysis observed in the cigarette smoke-exposed rats Our results suggest that those purinergic enzyme alterations observed in the cigarette smoke-exposed rats could be related to an excessive platelet aggregation and point toward the potential of Cur to modulate purinergic signalling and, consequently, regulate the thrombus formation., (Copyright © 2011 John Wiley & Sons, Ltd.)

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.