Trypanosoma evansi infection on levels of copper, iron, and zinc in the plasma of rats

Cattle naturally infected by Eurytrema coelomaticum: Relation between adenosine deaminase activity and zinc levels

The enzyme adenosine deaminase (ADA) is critical for modulating the immune system, and in the presence of zinc, its activity is catalyzed. The aim of this study was to evaluate the ADA activity in pancreas of cattle naturally infected by Eurytrema coelomaticum in relation to the results of zinc levels, pathological findings and parasite load. For this study 51 slaughtered cattle were used. The animals were divided into two groups: Group A consisting of animals naturally infected by E. coelomaticum (n=33) and Group B of uninfected animals (n=18). Blood and pancreas were collected of each animal for analysis of zinc and ADA, respectively. Infected cattle showed a reduction on seric levels of zinc, and decreased ADA activity in the pancreas (P>0.05). A positive correlation between zinc levels and ADA activity was observed. Thus, high parasite load and severity of histopathologic lesions affect the ADA activity in pancreas, as well as the zinc levels in serum of infected animals (negative correlation between these variables). Therefore, we can conclude that cattle infected by E. coelomaticum have low ADA activity in pancreas, which can be directly related to zinc reduction, responsible for ADA activation and catalyzes.

Effect of zinc supplementation on E-ADA activity, seric zinc, and cytokines levels of Trypanosoma evansi infected Wistar rats

The aim of this study was to evaluate the effect of zinc supplementation on the ecto-adenosine deaminase activity (E-ADA), zinc seric levels and cytokines (TNF-α, IL-1, IL-6, and IL -10) on rats experimentally infected by Trypanosoma evansi. Four groups with 10 rats each were used as negative controls (groups A and B), while the animals from the groups C and D were infected intraperitoneally with 0.1 mL of cryopreserved blood containing 1.4 × 10(4) of trypanosomes. Animals of groups B and D received two doses of Zinc (Zn) at 5 mg kg(-1), subcutaneously, on the 2nd and 7th day post-infection (PI). Blood samples were collected on days 5 (n = 5) and 15 PI (n = 5). Zn supplementation was able to increase the rat's longevity and to reduce their parasitemia. It was observed that seric Zn levels were increased on infected animals under Zn supplementation. Animals that were infected and supplemented with Zn showed changes in E-ADA activity and in cytokine levels (P < 0.05). Zn supplementation of healthy animals (Group B), increased the E-ADA activity, as well as reduced the concentration of cytokines. Infected animals from groups C and D showed increased levels of cytokines. Finally, we observed that Zn supplementation led to a modulation on cytokine's level in rats infected by T. evansi, as well as in E-ADA activity.

Iron metabolism and its relationship to anemia and immune system in Trypanosoma evansi infected rats

The aim of this study was to evaluate biochemical parameters of iron metabolism in rats experimentally infected with Trypanosoma 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.