Adenosine Levels in Serum and Adenosine Deaminase Activity in Blood Cells of Dogs Infected byRangelia vitalii

Abstract

Ecto-adenosinedeaminase (E-ADA) plays an important role in the production and differentiation of blood cells as well as in the control of extracellular adenosine levels. Infectious diseases can influence the synthesis of new cells or cause cell destruction, as occurs in canine rangeliosis, which results in anemia, thrombocytopenia, leukocytosis, and/or leukopenia. Thus, this study aimed to evaluate E-ADA activity in sera, erythrocytes, lymphocytes, and adenosine levels in sera samples of dogs infected by Rangelia vitalii. Twelve animals were divided into 2 groups: noninfected (n = 5) and infected by R. vitalii (n = 7). Animals were infected with 2 ml of blood containing the parasite, and parasitemia was estimated daily for 20 days by microscopic examination of peripheral blood smears. Blood collection was performed on days 0, 10, and 20 post-infection (PI) in order to evaluate the evolution of the disease. The blood collected was used to assess the activity of E-ADA. We observed an increase of E-ADA activity in sera (day 20 PI) and erythrocytes (days 10 and 20 PI) in the infected group (P < 0.05). E-ADA activity in lymphocytes was decreased on day 10, when the parasitemia was high, and increased after 20 days, when the number of circulating parasites was low. HPLC measured adenosine levels in the serum and found a reduction on days 10 and 20 PI. In conclusion, our results showed that E-ADA activity was altered in sera, lymphocytes, and erythrocytes of dogs experimentally infected by R. vitalii as well as the serum concentration of adenosine. These alterations may contribute to the pathogenesis of anemia and immune response in infected dogs.

Simultaneous determination of cordycepin and its metabolite 3′‐deoxyinosine in rat whole blood by ultra‐high‐performance liquid chromatography coupled with Q Exactive hybrid quadrupole orbitrap high‐resolution accurate mass spectrometry and its application to accurate pharmacokinetic studies

“…Therefore, the stability of COR in rat matrices followed the order: whole blood ≈ hematocyte > plasma. This finding could be because the activities of ADA in the rat's whole blood, plasma, and hematocyte of rat were different (whole blood ≈ hematocyte > plasma), which is consistent with the results reported in the literature [25]. To inhibit the degradation of COR in collected rat blood samples, ADA inhibitor EHNA was initially selected as the stabilizer of COR.…”

Effects of reduction of adenosine deaminase activity in the serum of dogs naturally infected by Ehrlichia canis and Hepatozoon canis

“…Our results are concordant with the findings reported by other researchers relating to experimental infection of dogs with E. canis (Da Silva et al 2013a) and Rangelia vitalii (Da Silva et al 2013b). Considering the immune response of diseases, it is generally recognized that cell-mediated immunity is important in protection against intracellular parasites.…”

Involvement of cholinergic and adenosinergic systems on the branchial immune response of experimentally infected silver catfish with Streptococcus agalactiae

“…Recently, a study conducted by Da Silva et al. () demonstrated that upregulation of ADA activity contributed to intense inflammatory damage in dogs naturally infected with the protozoan Rangelia vitalii, which contributes directly to disease pathophysiology. In particular, Domínguez Artiga, Holanda Peña, Velasco, Orozco Abril, and Teja Barbero () demonstrated that upregulation of ADA activity may have contributed to disease pathogenesis during bacterial meningitis caused by Streptococcus pneumoniae , in accordance to results observed in the present study.…”