LIPID CONTENT OF MITOCHONDRIA FROM TRANSPLANTABLE ANIMAL TUMOURS

1. 1. Ehrlich ascites tumour mitochondria are shown to contain 34% lipid (by wt.), 91% of which is phospholipid. This is about twice the content of liver mitochondria and more than that of heart mitochondria. 2. 2. Measurements of the cytochromes and soluble compartments provide evidence against the observation being an artifact produced by loss of soluble protein from tumour mitochondria during their isolation from the cells. 3. 3. Thin-layer chromatography shows that the same lipids are common to tumour, heart and liver mitochondria and are present in about the same proportions. 4. 4. Several other transplantable tumours (solid and ascitic) were studied and all have a high content of phospholipid, suggesting this is a general characteristic of transplantable tumours. 5. 5. These observations are not explicable in terms of the inner membrane content of the mitochondria. Whether they relate to the size of tumour mitochondria or represent an abnormality in their membrane or matrix composition cannot be determined without measurements of the relevant outer membrane areas in relation to mitochondrial volume. 6. 6. Possible aetiological factors are briefly discussed. © 1969.