RESUMO
This study aimed to evaluate the adenine nucleotides and nucleoside concentration in serum and cerebral cortex of rats infected with Trypanosma evansi. Each rat was intraperitoneally infected with 1 × 10(6) trypomastigotes suspended in cryopreserved blood (Group A; n = 18). Twelve animals were used as controls (Group B). The infected animals were monitored daily by blood smears. At days 4 and 20 post-infection (PI) it was collected serum and cerebral cortex to measure the levels of ATP, ADP, AMP and adenosine by high performance liquid chromatography (HPLC). In serum there was a significant (P < 0.05) increase in the ATP, AMP and adenosine concentrations at days 4 and 20 PI in infected rats when compared to not-infected. Furthermore, in the cerebral cortex it was observed a significant (P < 0.05) increase in the concentrations of ATP, AMP and decreased adenosine levels at day 4 PI. At day 20 PI it was only observed an increase in the AMP and adenosine concentrations in cerebral cortex of infected rats when compared to not-infected. It was not observed any difference in ADP concentration in serum and brain at days 4 and 20 PI. No change was observed histologically in the cerebral cortex of infected animals. The results allow us to conclude that infection with T. evansi in rats causes an increase in the concentrations of ATP, AMP and adenosine in serum and cerebral cortex the time periods evaluated. These alterations occurred as a result of T. evansi infection which involves neurotransmission, neuromodulation and immune response impairment confirm the importance of the purinergic system in this pathology.