Juan Tentoni

Comparative vertebrate fibrinolysis

Fibrinolysis is a feature in the phylogeny of vertebrates. This review analyzes the fibrinolytic mechanism in different species compared to healthy adult humans. Additionally, it introduces the armadillo Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae) whose lytic process remains quite unknown until now. The analysis was conducted in a phylogenetic order: fish, amphibians, reptiles, birds, and mammals. It was designed to assess the fibrinolytic system in its various stages: global, specific, and degradation. The results are represented in tables grouped by test: fibrinogen, whole blood lysis time, whole blood diluted lysis time, euglobulin lysis time, plasminogen, fibrin/fibrinogen degradation products, D dimer, plasminogen activator inhibitor type 1, and alpha 2 antiplasmin activity. Global knowledge of the mechanism of fibrinolysis in vertebrates is a contribution of scientific interest not only in biology, but also for the development of experimental models applicable to the study of thrombotic and thrombolytic agents.

Fibrinolytic system of the armadillo Chaetophractus villosus (Xenarthra, Dasypodidae)

The fibrinolytic mechanism in the armadillo Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae) quite unknown until now was studied. Results were compared with those corresponding to healthy adult human beings. Whole blood lysis time and diluted blood lysis time were not detectable in armadillos. Euglobulin clot lysis time and plasminogen activity (Plg) were lower than in healthy humans. We established the presence of the fibrinolytic system in Ch. villosus through the measurement of fibrin fibrinogen degradation products. The activity of the plasminogen activator inhibitor was two to four times greater than in healthy humans. The activity of the alpha 2 anti-plasmin (α2AP) was similar and displaced toward lower values. The Plg/α2AP relation was lower. The results obtained suggest that Ch. villosus has a hypercoagulable and hypofibrinolytic profile. Our findings are not only the first contribution to elucidate the physiology of the fibrinolytic system in Xenarthra but also contribute to develop an animal model for studies in haemostasis and thrombosis.