Histological changes of intravascular coagulation in mice resulting from intravenous injection of C. parvum.

A histological study was made of liver and other tissues of mice at intervals after injection of C. parvum. As early as 20 min after injection occasional thrombi surrounded by polymorphs were seen in the alveolar capillaries. A general thrombosis rapidly developed in the hepatic vessels with consequent hepatic necrosis. Thrombi also developed in splenic vessels. This intravascular coagulation was prolonged, lasting at least 7 days. There was evidence that fresh thrombi were being formed throughout this time. The thrombosis was mirrored by a fall in platelet counts. The kidney was uninvolved in the reaction. The mechanism of this reaction and its possible relevance to the antitumour action of C. parvum is discussed.