[Some characteristics of isoenzymic spectrum of hexokinase and glucose levels in hepatomas and liver of the host].

The total activity of hexokinase (HK) and HK isoenzymic spectrum of the normal liver and slowly groming hepatoma 49 did not show any essential differences. However, the HK total activity and the relative and absolute contents of isoenzyme HK-3 were increased in hepatomas 61 and especially in the rapidly growing hepatoma 22-a. The glucokinase activity decreases in the hepatiomas 49 and 61 and disappears in the rapidly growing hepatoma 22-a. The glucose content in hepatoma 49 was slightly lower than in the normal liver, whereas in other hepatoma no traces of glucose could be detected. At low glucose concentration in the medium (0,1 mM), i.e. under conditions simulating those characteristic of tumors in vivo, the predominant form of HK in all hepatomas studied was found to be HK-3. In the liver of hepatoma-bearing mice some shifts in the value of total HK activity and its isoenzymic spectrum, reminding one of those found in hepatomas themselves, were observed. Unequal deviations in the total HK activity and its isoenzymic spectrum in hepatomas with different degrees of malignancy indicate that these characteristics are secondary rather than primary events depending on tumour progression.