title: Activities of ectonucleotidases and adenosine deaminase in platelets of dogs experimentally infected with Rangelia vitalii.
abstract: 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.
authors.affiliation: Department of Small Animals, Universidade Federal de Santa Maria, Brazil. brenopaim@ufsm.br
authors.forename: Carlos Breno V
authors.initials: CB
authors.lastname: Paim
authors.forename: Aleksandro S
authors.initials: AS
authors.lastname: Da Silva
authors.forename: Francine C
authors.initials: FC
authors.lastname: Paim
authors.forename: Raqueli T
authors.initials: RT
authors.lastname: França
authors.forename: Marcio M
authors.initials: MM
authors.lastname: Costa
authors.forename: Viviane C G
authors.initials: VC
authors.lastname: Souza
authors.forename: Victor C
authors.initials: VC
authors.lastname: Pimentel
authors.forename: Jeandre A
authors.initials: JA
authors.lastname: Jaques
authors.forename: Cinthia M
authors.initials: CM
authors.lastname: Mazzanti
authors.forename: Daniela B R
authors.initials: DB
authors.lastname: Leal
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Monteiro
authors.forename: Maria Rosa C
authors.initials: MR
authors.lastname: Schetinger
authors.forename: Sonia T A
authors.initials: ST
authors.lastname: Lopes
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000243:Adenosine Deaminase / Q000097:blood*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001403:Babesia / Q000502:physiology*; D001404:Babesiosis / Q000097:blood / Q000201:enzymology / Q000662:veterinary*; D001778:Blood Coagulation Disorders / Q000469:parasitology / Q000662:veterinary; D001792:Blood Platelets / Q000201:enzymology*; D001938:Brazil; D003641:Deamination; D004283:Dog Diseases / Q000097:blood* / Q000201:enzymology / Q000469:parasitology; D004285:Dogs; D005260:Female; D006470:Hemorrhage / Q000469:parasitology / Q000662:veterinary; D006868:Hydrolysis; D009708:Nucleotidases / Q000097:blood*; D010976:Platelet Count / Q000662:veterinary
chemical_list: D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009708:Nucleotidases; D000243:Adenosine Deaminase; D000241:Adenosine