title: Maturation dependence of the turnover of phosphatidylinositides in rabbit red blood cells.
abstract: "Pulse-chase" experiments with erythrocytes and reticulocytes prelabelled with 32P-Pi revealed a high turnover of the monoester phosphate groups of PIP2 in reticulocytes, which declines strongly during maturation [Maretzki et al., Biomed. Biochim. Acta 45, 1227-1236 (1986)]. The 3H-inositol uptake exhibits a strong maturational loss. A carrier-mediated uptake of inositol in reticulocytes is suggested. In reticulocytes PI, PIP and PIP2 incorporated 3H-inositol in the relative distribution of 86; 5 and 9%, respectively, but only PI to a minor extent in erythrocytes. A small release of 3H-labelled inositol phosphates was found in reticulocytes, which was not stimulated by extracellular calcium during incubation. Determination of the 32P/3H-ratio in double-labelled phosphatidylinositides in reticulocytes demonstrated a very slow turnover of the diester phosphate bonds compared with that of the inositol phosphate ester groups.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D007700:Kinetics; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000097:blood*; D011817:Rabbits; D012156:Reticulocytes / Q000166:cytology / Q000378:metabolism
chemical_list: D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C037178:phosphatidylinositol 4-phosphate