A study of the free sugar concentration of the livers of rats absorbing glucose and fructose and its relationship to glycogen synthesis

Abstract

The absorption coefficients of glucose and fructose in 24 hr. fasted rats were approx. 250 and 160 mgm. per 100 gm., respectively; the values for young fasted rats (60 gm.) were 360 and 150. Very small amts. of insulin (1/4 unit) inhibited glycogen synthesis in fructose absorbing rats, but not in glucose absorbing rats. The liver and venous blood of fructose absorbing rats contained only traces of fructose. The ratio liver sugar/blood sugar was the same in fasting and in glucose and fructose absorbing rats was about 1.1. That fructose was a better hepatic glycogen precursor than glucose was confirmed.