Cholesterol bound to hemoglobin in normal human erythrocytes: a new form of cholesterol in circulation?
Abstract
Objective: To study lipid fraction that is occasionally observed in red blood cell (RBC) hemolysate (supernatants from which membranes were separated). Study design: Plasma lipid profiles, cholesterol (Ch) and phospholipids (PL) in intact RBCs, RBC membranes and hemolysates were examined in young healthy male population in winter and summer. Results: The RBC Ch and PL content was significantly higher than in membranes, both in winter and summer. The "excess" of cholesterol (associated with phospholipid) was bound to hemoglobin yielding Hb-lipid adduct (Hb-Ch), the pools in the RBC membrane remaining virtually unaltered. Levels of hemoglobin- lipid complex (Hb-Ch), which were significantly higher in winter than in summer (30% and 19% of the total Hb, respectively), positively correlated with plasma HDL cholesterol levels. Conclusion: To our knowledge, this is the first demonstration of cholesterol binding to Hb. The results suggest influence of plasma lipoprotein metabolism on the forma...tion of Hb-Ch. (C) 2003 The Canadian Society of Clinical Chemists. All rights reserved.
Keywords:
cholesterol / HDL cholesterol / hemoglobin / red blood cells / hemoglobin-lipid / seasonal variationSource:
Clinical Biochemistry, 2004, 37, 1, 22-26Publisher:
- Elsevier
DOI: 10.1016/j.clinbiochem.2003
ISSN: 0009-9120
PubMed: 14675558