RESUMO
Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5´-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection.Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10
Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5´-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection.Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10
RESUMO
Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5´-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection.Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10
Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5´-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection.Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10