a1 Laboratoire des Protéines UA CNRS U88, Université de Paris V, 45 rue des Saints-Pères, F-75270 Paris Cedex 06, France
a2 Hôpital Lariboisière, INSERM U 150 and CNRS LA 334, 6 rue Guy Patin, F-75475 Paris Cedex 10, France
Casein and other milk proteins in maternal colostrum and milk, the earliest food of the newborn, should not only be considered as a nutritional supply but also as a source of biologically active peptides. Some of them isolated from casein and lactotransferrin were active on platelet function. They inhibited both aggregation of ADP-treated platelets and binding of [125I] fibrinogen to ADP-treated platelets. Their behaviour was compared to that of fibrinogen peptides possessing similar effects: once more similarities between the milk and blood-clotting phenomena could be observed.