Hypersplenism--effect on haemostasis. An experimental study in the rat.

Hypersplenism induced by methylcellulose given to rats i.p. was characterized by splenomegaly, anaemia, leucocytopenia and thrombocytopenia. Hb, Hct and WBC count were normalized, and platelet count rose to supernormal values by splenectomy. At a standardized liver resection, the hypersplenic rats had an increased blood loss and prolonged bleeding time in comparison with control rats. Removal of the large spleen normalized these abnormalities. Hypersplenism also shortened APT time and impaired ADP and collagen-induced platelet aggregation, findings not normalized by splenectomy.