Beziehungen zwischen Hexokinaseaktivität und Glykolyse in Rattenleber und Hepatomen

Abstract

Normal and precancerous livers as well as primary and transplanted hepatomas are studied for glycogen content, hexokinase- and glucokinase activity, at the same time measuring glycolysis in the high-speed supernatants of these tissues with different substrates and additives. Experimental results show that: 1) normal and precancerous rat livers have low hexokinase activity and low glycolysis, but high glucokinase activity and high glycogen content; 2) primary DAB hepatomas. on the contrary, have high hexokinase activity and raised glycolysis as well as low glycokinase activity and low glycogen content; 3) transplantable DAB- as well as DENA-hepatomas have high hexokinase activity and high glycolyses. while neither glucokinase activity nor glycogen content have been found; 4) when using glucose as substrate and adding exogenous hexokinase. there is a considerable increase in formation of lactic acid in all tissue supernatants investigated; 5) if glucose-6-phosphate is used instead of glucose, a considerable increase of glycolysis is noted as well. It is concluded from the results obtained that the hexokinase reaction limits the extent of glycolysis in these tissues.