Author: Julius George Bekesi

Publisher:

Published: 1964

Total Pages: 0

ISBN-13:

The present investigation was undertaken to study the effect of malignant disease on human and on rat plasma glycoproteins. The levels of galactose and mannose in plasma glycoproteins, in the absence of the seromucoid fraction, were determined in 654 human subjects. This group consisted of healthy individuals as well as patients suffering from malignant and non-malignant disease. In 118 representative patients the analysis was extended to include individual determinations of hexoses (galactose-mannose), hexosamines (glucosamine-galactosamine), N-acetylneuraminic acid and fucose in the plasma glycoproteins. Levels of carbohydrate in the plasma glycoproteins of patients with malignant disease showed significant elevation as compared with levels observed in normal individuals and patients with non-malignant disease. The behaviour of the various protein-bound carbohydrates in patients with localized carcinoma of the breast differed from that observed in patients with other types of malignancy or suffering from carcinoma of the breast with metastases. In ten patients with malignant disease, serial quantitative determinations of plasma glycoproteins indicated that these protein- carbohydrate complexes are intimately related to the neoplastic process. In order to determine the relationship between the plasma glycoproteins and tumour growth, adult Sprague-Dawley rats were implanted with Walker-256 carcinoma and serial determinations of the plasma protein-bound carbohydrates carried out. A total of 95 rats formed the test group and the animals were sacrificed at intervals following intramuscular implantation of the tumour. A control group of 32 rats was sacrificed at corresponding intervals following intramuscular injection of an homologous muscle homogenate. Changes in the levels of galactose-mannose, glucosamine- galactosamine, N-acetylneuraminic acid and fucose of the total plasma glycoproteins, as well as the hemoglobin, hematocrit and total plasma protein were determined. It was observed that the growth of Walker-256 carcinoma in the rat following implantation is associated with significant increases in the carbohydrate constituents of the plasma glycoproteins. However, the interval between implantation and the occurrence of a significant increase is different for each carbohydrate, and the magnitude of the increase is likewise not uniform. These observations would suggest that the site or the rate of synthesis of the various carbohydrate moieties of the plasma glycoproteins may not be similar, as is commonly believed.