Erythrocyte contamination of leukocyte populations following density‐gradient centrifugation results in artificially high levels of human leukocyte HMG‐CoA reductase activity

• Published in: Lipids Vol. 23; no. 12; pp. 1154 - 1158
• Main Authors: Harwood, H. James, Bridge, Donna M., Stacpoole, Peter W.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer‐Verlag 01.12.1988; Springer
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Blood Proteins - analysis; Catalysis; Centrifugation, Density Gradient; Enzymes and enzyme inhibitors; Erythrocytes - enzymology; Fundamental and applied biological sciences. Psychology; Humans; Hydroxymethylglutaryl CoA Reductases - blood; Leukocytes - enzymology; Microsomes - enzymology; Oxidoreductases; Reproducibility of Results; Human; Density gradient centrifugation; Enzymatic activity; Radiolabelling; Enzyme; Leukocyte; Red blood cell; Hydroxymethylglutaryl-CoA reductase; Contamination; Blood
• ISSN: 0024-4201; 1558-9307
• DOI: 10.1007/BF02535283

When measuring human leukocyte HMG‐CoA reductase activity, special care must be taken to prevent erythrocyte contamination of the leukocyte layer during isopycnic centrifugation. Contamination during leukocyte isolation and subsequent erythrocyte lysis during NH4Cl treatment results in increased leukocyte microsomal HMG‐CoA reductase activity. Increased enzyme activity is not due to enzyme dephosphorylation, thiol‐disulfide reduction or increased enzyme protein concentration. Leukocyte populations containing granulocytes appear to be most sensitive. Prevention of erythrocyte contamination during isopycnic centrifugation should aid in accurate measurement of human leukocyte HMG‐CoA reductase activity.