Adaptative changes of activity of enzymes involved in fructose metabolism in the liver and jejunal mucosa of rats following fructose feeding.
The adaptative response of a diet containing 60% fructose on the activity of those enzymes which are involved in the metabolism of fructose was measured in the liver and in the jejunal mucosa of rats over a period of 12 days. Control animals received isocaloric amounts of glucose or starch. Under fructose feeding there was a marked increase in the activity of fructose-1-phosphate aldolase (3-fold), ketohexokinase (2--3-fold), and triokinase (3-fold) in the jejunal mucosa. In the liver, however, a significant increase in enzyme activity could only be seen for triokinase (2--3-fold), whereas the activity of the other enzymes measured were only slightly or not at all altered. The activity of the three enzymes mentioned above were elevated to a maximum within 3 days after feeding the fructose diet. In the following time of observation no major further changes occurred. The results show that fructose feeding in comparison to a glucose or starch containing diet leads to a marked adaptative increase in the activity of those enzymes, which are involved in the breakdown of fructose, only in the jejunal mucosa.
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000818:Animals; D004040:Dietary Carbohydrates / Q000378:metabolism*; D002149:Energy Intake; D005260:Female; D005631:Fructokinases / Q000378:metabolism; D005632:Fructose / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007413:Intestinal Mucosa / Q000201:enzymology*; D007583:Jejunum / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D010770:Phosphotransferases / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor); D051381:Rats; D014306:Trioses / Q000378:metabolism
D004040:Dietary Carbohydrates; D014306:Trioses; D005632:Fructose; D000429:Alcohol Oxidoreductases; D010770:Phosphotransferases; D005631:Fructokinases; D017853:Phosphotransferases (Alcohol Group Acceptor); C023190:triokinase; D005634:Fructose-Bisphosphate Aldolase; D005947:Glucose