OBJECTIVE: The interior of red blood cells (RBCs) contains a variable amount of cholesterol and phospholipids bound to haemoglobin (Hb). This current study was devised to determine if this pool of lipids (termed Hb-Ch) was available for exchange with plasma lipoproteins. DESIGN AND METHODS: We studied the in vitro efflux of lipids from human RBCs into fasting plasma in men with either low (control group) or high Hb-Ch (study group). RESULTS: When plasma was incubated with a two-fold excess of autologous RBCs the plasma cholesterol level increased due to a decrease in the level of cholesterol from the RBC membrane (in the control group) and due to a decrease in the level of cholesterol both from the RBC membrane and the Hb-Ch fraction (in the study group). The loss of Hb-Ch-derived phospholipids during lipid efflux was roughly equal to that of Hb-Ch-derived cholesterol. The loss of RBC cholesterol into plasma high-density lipoproteins (HDL) was more pronounced in our study group and correlated with the loss of cholesterol from Hb-Ch. CONCLUSION: The Hb-Ch adduct significantly contributes to the lipid efflux from RBCs into plasma. The majority of cholesterol released from Hb-Ch appears in the plasma HDL fraction suggesting that Hb-Ch may play a role in reverse cholesterol transport in vivo.
OBJECTIVE: The interior of red blood cells (RBCs) contains a variable amount of cholesterol and phospholipids bound to haemoglobin (Hb). This current study was devised to determine if this pool of lipids (termed Hb-Ch) was available for exchange with plasma lipoproteins. DESIGN AND METHODS: We studied the in vitro efflux of lipids from human RBCs into fasting plasma in men with either low (control group) or high Hb-Ch (study group). RESULTS: When plasma was incubated with a two-fold excess of autologous RBCs the plasma cholesterol level increased due to a decrease in the level of cholesterol from the RBC membrane (in the control group) and due to a decrease in the level of cholesterol both from the RBC membrane and the Hb-Ch fraction (in the study group). The loss of Hb-Ch-derived phospholipids during lipid efflux was roughly equal to that of Hb-Ch-derived cholesterol. The loss of RBC cholesterol into plasma high-density lipoproteins (HDL) was more pronounced in our study group and correlated with the loss of cholesterol from Hb-Ch. CONCLUSION: The Hb-Ch adduct significantly contributes to the lipid efflux from RBCs into plasma. The majority of cholesterol released from Hb-Ch appears in the plasma HDL fraction suggesting that Hb-Ch may play a role in reverse cholesterol transport in vivo.
Authors: Vid Suštar; Apolonija Bedina-Zavec; Roman Stukelj; Mojca Frank; Eva Ogorevc; Rado Janša; Keriya Mam; Peter Veranič; Veronika Kralj-Iglič Journal: Lipids Health Dis Date: 2011-03-21 Impact factor: 3.876
Authors: Solomon O Rotimi; David A Ojo; Olusola A Talabi; Regina N Ugbaja; Elizabeth A Balogun; Oladipo Ademuyiwa Journal: Lipids Health Dis Date: 2015-02-21 Impact factor: 3.876