Negative feedback in the fructose metabolism in liver
The main reaction of fructose in liver is phosphorylation, catalyzed by ketohexokinase (UniProt P50053). In one paper with rats it was shown that fructose load can deplete the liver of nucleotide triphosphates (ATP, GTP) although ADP and GDP are inhibitors of the enzyme. This shows there is no effective regulation.

M. I. Phillips, D. R. Davies: The mechanism of guanosine triphosphate depletion in the liver after a fructose load. The role of fructokinase. In: The Biochemical journal. Vol 228, Nr 3, Jun 1985, p.&nbsp;667–671, {{ISSN|0264-6021}}. PMID 2992452. PMC 1145036.