EFFECT OF SOME DRUGS ON HEXOSAMINE SYNTHESIS IN EHRLICH ASCITES CARCINOMA CELLS AND ON HYALURONIC ACID CONTENT IN THE ASCITIC FLUID

Relationship between the growth of Ehrlich ascites carcinoma and changes in the hyaluronic acid content in the ascitic fluid was investigated. The concentration of hyaluronic acid in ascitic fluid was maintained at about 40mg% during the active development of tumor cells and then increased abruptly in the later stage. When tumor-bearing mice were treated with D-galactosamine, the total amount and concentration of hyaluronic acid in the ascitic fluid on the 12th day after tumor inoculation decreased significantly. All the anticancer agents tested, except Nitromin, caused an increase in the hyaluronic acid concentration. To elucidate these changes further, hexosamine synthesis in tumor cells was examined and the strongest activity was observed in the earlier stage of tumor development. The hexosamine synthesis in tumor cells was not affected either in vitro or in vivo by amino-sugars or anticancer agents other than Nitromin. Morphology and histochemistry of tumor cells were also studied and it was suggested that the elevation of hyaluronic acid concentration in the ascitic fluid might be related to the breakdown of tumor cells.