title: Exchange of phosphatidylcholine between rabbit erythrocytes and plasma in vivo.
abstract: Phosphatidylcholine exchange between rabbit erythrocytes and plasma was studied in vivo. The erythrocyte phosphatidylcholine was labeled by exchange in vivo with [32P] phosphatidylcholine and in vitro by acylation with [3H] 16:0 and [14C] 18:2. The erythrocytes were then injected into rabbits and the loss of labeled phosphatidylcholine from the cells by exchange was followed. The rate constants for the exchange of [32P]-, [3H] 16:0-, and [14C] 18:2-phosphatidylcholine were .013 +/- .0010, .0093 +/- .0014 and .0074 +/- .0013 h-1, and the exchange rates of the labels relative to that of [32P] were 1.0, 0.71 +/- .16, and 0.56 +/- .14, respectively. These results confirm our earlier in vitro findings and represent the first in vivo demonstration of the dependency of the exchange rate of erythrocyte phosphatdylcholines on their metabolic prehistory.
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D004912:Erythrocytes / Q000378:metabolism*; D007700:Kinetics; D010713:Phosphatidylcholines / Q000097:blood*; D010761:Phosphorus Radioisotopes; D010949:Plasma / Q000378:metabolism*; D011817:Rabbits; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D010713:Phosphatidylcholines; D010761:Phosphorus Radioisotopes; D014316:Tritium