Studies on the Aging of Human Erythrocytes in vitro

Erythrocyte Membrane Vesiculation and Changes in Membrane Composition during Storage in Citrate-Phosphate-Dextrose-Adenine-1

“…The size, configuration and biochemical composition of the vesicles found in our samples are similar to those described by others whether formed by red cells depleted rapidly of ATP [8,32], more slowly during refrigerated storage [6,7] or in the presence of4MNaCl [38], The relatively low values for lipid losses found by us and the wide ranges of values reported in the literature can be explained by the higher values of ATP maintained in the presence of adenine and the use of plastic versus the glass con tainers by others [4,[6][7][8][9]27,28,39,40]. The recent finding by Estep [personal commun.…”

“…The accumu lation of 1, 2-diacylglycerol formed by the action of a Ca2+-activated phospholipase on phosphatidylcholine (PC) in the outer leaflet of the membrane was suggested as the mech anism of the exocytosis [5], Subsequent workers have questioned the validity of this hypothesis because sheep red cells which contain no PC act similarly [30,31] and because vésiculation can be produced in the presence of EGTA with no added Ca2+ [32]. More recently, evidence has been presented that the diacylglycérol is formed by the ac tion of a Ca2+-activated phosphodiesterase on phosphatidylinositol phosphate and phosphatidylinositol diphosphate [33][34][35], Most recently, the role of Ca2+ in the shape transformation which follows ATP deple tion has also been questioned [36], A num ber of studies using conditions which cause rapid depletion of ATP and simulated blood bank conditions have established the forma tion of 60-200-nm vesicles [6][7][8]37].…”

“…The demonstration by Allan and Micheli [5] that microvesiculation could be induced by treating erythrocytes with Ca2+ and the ionophore A23187 \eà Rumsby &ia\. [6,7] to look for vesicles in the plasma of stored blood. It appeared logical to expect the for mation of exocytic vesicles during storage accompanying ATP depletion and the pre sumed increase in available Ca2+ in the cy tosol.…”

The Lecithin: Cholesterol Acyltransferase Reaction, Lysolecithin and Red Cell Ageing in Blood Stored under Normal Transfusion Service Conditions

“…This will be accompanied by the release of free fatty acids. It is well establish ed that erythrocytes loose phospholipid during storage at 4 °C in ACD [14,20], but under these conditions it has generally been assumed that there is no change in the overall level of total lipid phosphorus in whole blood. Etienne and Polonovski [7] have reported that, when human serum is incubated at 37 °C for 72 h, there is a decrease in the total phospholipid content and that the loss of lipid is associated with the lecithin fraction which was found to decrease by as much as 40%.…”

Storage of Human Red Blood Cells and Platelets

“…During storage intracellular Ca '+ increases and ATP decreases (25,33,37,73,96). The echinocyte formation and vesiculation (budding of the thin spicules) can be induced by treating fresh cells with Ca2+ and ionophore A 23187 (1,Z).…”