Changes in hematological, hemostatic and biochemical parameters induced experimentally in rabbits by Loxosceles gaucho spider venom.
Human accidents caused by Loxosceles spiders may result in local dermal necrosis and, in some cases, severe systemic reactions - such as intravascular hemolysis, disseminated intravascular coagulation (DIC), renal failure and death. Since many aspects of envenomation by Loxosceles spiders remain unclear, we studied the hematological and hemostatic responses induced by the i.d. injection of 10 microg/kg Loxosceles gaucho venom in rabbits. For this purpose, total blood cell count, platelet function, coagulation tests and biochemical parameters were analysed at 3, 24, 48, 72 and 120 hours after venom administration. Thrombocytopenia and leukopenia were noted at 3 and 24 hours. Histopathological analysis of the skin lesion, performed at 24 hours after venom administration, showed a massive presence of leukocytes and platelets, hemorrhage and thrombus formation at the injection site. At 72 and 120 hours, neutrophilic leukocytosis and thrombocytosis were observed. Platelet hyperaggregation was noticeable at 48 and 72 hours. Haptoglobin and fibrinogen levels were elevated early and remained in high levels over time. Significant increases in coagulation factors V, VII, VIII, IX, X and XI were noted at 120 hours. The results showed that neither intravascular hemolysis nor DIC occurred. However, the early onset of thrombocytopenia and leukopenia are important findings that may be related to dermal necrosis formation during loxoscelism.
Tavares
Flávio Luiz
FL
Laboratory of Pathophysiology, Institute Butantan, São Paulo-SP, Brazil. flutavares@butantan.gov.br
Sousa-e-Silva
Maria Cristina Cirillo
MC
Santoro
Marcelo Larami
ML
Barbaro
Kátia Cristina
KC
Rebecchi
Ivanise Marina Moretti
IM
Sano-Martins
Ida Sigueko
IS
D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects* / Q000502:physiology; D019963:Clinical Chemistry Tests; D006403:Hematologic Tests; D007271:Injections, Intradermal; D007970:Leukopenia / Q000097:blood / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000008:administration & dosage / Q000633:toxicity*; D011817:Rabbits / Q000097:blood*; D012697:Serine Endopeptidases / Q000008:administration & dosage / Q000633:toxicity*; D012867:Skin / Q000187:drug effects / Q000473:pathology; D013111:Spider Venoms / Q000008:administration & dosage / Q000633:toxicity*; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced* / Q000473:pathology
D013111:Spider Venoms; C055161:loxosceles venom; D010727:Phosphoric Diester Hydrolases; D012697:Serine Endopeptidases