RESUMO
Plasma membranes of rat platelets produced at normal platelet counts and during early recovery from immune-mediated thrombocytopenia were examined for the contents of carbohydrates, lipids and glycosphingolipids. Glucosylceramide, two monosialo-gangliosides and one disialo-ganglioside were found to be the major glycosphingolipids of platelets. During thrombocytopenia the contents of these glycosphingolipids as well as of ceramides were several fold elevated. Among carbohydrate constituents of platelets and platelet plasma membranes, glycogen content was increased and that of sialic acid decreased. These results are discussed in the light of literature data on relevant biochemical characteristics of megakaryocytes at different stages of maturation and on thrombopoiesis during acute experimental thrombocytopenia.