[The effect of fructose on glucose formation and oxydation in healthy subjects and patients with liver cirrhosis].

The effect of fructose infusions (1.0 g/kg/g) on serum glucose, insulin, lactate, free fatty acids, glucose production and glucose oxidation was investigated with 14C-glucose in 10 normals and 11 patients with liver cirrhosis. Elevation of glucose and insulin were small and only slightly higher in cases of cirrhosis. Decrease of free fatty acids and rise of lactate were approximately the same in both groups. During infusion of fructose glucose turnover increased up to 196 +/- 41% in the normals and up to 279 +/- 78% in the patients with cirrhosis. No influence on the specific activity of 14CO2 was observed. It was therefore suggested, that approximately the same amount of glucose leaving the liver in excess during infusion of fructose was taken up by the liver at the same time. This behaviour of glucose supply to the blood stream and removal from it would explain, why high rates of conversion of fructose to glucose were measured with 14C-fructose, while only small amounts of glucose production were estimated from hepatic arteriovenous differences.