[Changes in the phospholipid content and the antioxidant activity of erythrocyte lipids in mammary gland tumors and during radiotherapy].

Changes in the phospholipid content and the antioxidant activity of the lipid fractions of erythrocytes in patients with different mammalian gland tumours, e. g. fibroadenoma, fibrocystic mastopathy and carcinomas, before and after radiotherapy were studied. It was found that the content of individual phospholipid fractions and their physico-chemical properties vary depending on the type of the tumour. Nevertheless in all cases studied the sphingomyelin content in the erythrocytes at early stages of malignancy is increased, with a maximum exceeding ther normal level 2-fold. Changes in the content of other phospholipids depend on the degree of malignancy and are especially well-pronounced in the neoplasm and at early stages of neogenesis. The phosphatidyl ethanolamine and phosphatidyl serine content in the erythrocytes in fibro-cystic mastopathy is decreased, while that of lysophosphatidyl choline is increased (more than 3-fold). The phosphatidyl choline content is considerably increased in fibroadenoma and is decreased in fibro-cystic mastopathy and carcinomas with a diameter of less than 2 cm. The antioxidant activity of the erythrocyte lipids significantly exceeds the normal level in benign tumours of the mammalian gland and at early stages of neogenesis. Further malignancy is accompanied by a decrease of the antioxidant activity of erythrocytes below the normal level and by an appearance of phosphatidyl inositol in the phospholipid fraction.