Métabolisme phospholipidique des hématies nucéées

Incorporation of [32P]orthophosphate into chicken and chick‐erythrocyte and plasma phospholipids in vivo was studied by means of one and two‐dimensional thin‐layer chromatography between 3 and 144 h. Radiophosphate was actively incorporated into plasma phospholipids, more rapidly into chick than chicken (maximum specific activity after 6 and 12 h, respectively) and more slowly into erythrocyte phospholipids. After 12 h, the chicken‐plasma phospholipids were labelled in the order: phosphatidylcholine, phosphatidyléthanolamine, lysophosphatidylcholine, phosphatidylinositol, sphingomyelin and phosphatidylserine; while the chick‐plasma phospholipids, after 6 h, were labelled in the order: phosphatidylethanolamine, phosphatidylcholine, lysophosphatidylcholine and sphingomyelin. In chick‐ and chicken‐erythrocyte phospholipids, higher specific activities, very similar for all the phospholipids studied, were observed at 144 h. These results strongly differ from those observed in in vitro incorporation: phosphatidic acid and phosphatidylglycerol were lowly labeled while phosphatidylserine showed high specific activities in the two experiments. Exchange reactions between plasma and erythrocyte phospholipids are not the same as in mammals; the high specific activities of the different erythrocyte phospholipids were too late for an exchange with plasma phospholipids. De novo biosynthesis was probably effective in the erythrocyte. The turnover of lysophosphatidyllcholine was low and the acylation of plasma phospholipids appeared less active than in mammal erythrocyte.