Ehrlich carcinoma and Sarcoma (Pearce and Brown, 1923;Black, 1964) and a few mouse tumors such as the Lewis lung sarcoma (Schatten, 1958; Ketcham et al., 1966).

No abstract

No abstract

Dear Madam, Thilo and Bohm (1973) have recently suggested that the platelet adhesion-aggregation reaction does not play a primary role in the very early phases of haemostasis. Since their experiments have been performed in rat, it seems hazardous to draw general conclusions about the haemostatic mechanism. We have indeed observed (de Gaetano et al., 1974) that rat platelets, in comparison with human and guinea pig platelets, are much less sensitive to collagen, to ristocetin and to some von Willebrand factor preparations. Defective rat platelet aggregation induced by the above mentioned stimuli has been found both in vitro (Born's aggregometer) and in vivo (method of Kobayashi and Didisheim, 1973). Rat platelets were also reported to adhere to tendon suspension (Constantine, 1967) and to glass beads (Nordoy and Odegaard, 1963) less readily than human platelets. In addition the 'thrombogenic activity' of injured rat vessels was lower than that of rabbit vessels (Born and Philp, 1965). As the animals used in all these experiments were not suffering from any haemorrhagic diathesis, it is conceivable that the mechanism of primary haemostasis in rat is quite different from that operating in other animal species, namely in man. The findings reported by Thilo and Bohm (1973) offer perhaps the first direct evidence for a peculiar haemostatic mechanism in rat.

No abstract