[Effect of fructose on the hexosamine turnover in the rat crystalline lens]

Rats were given isocaloric rations containing starch (control) and varying amounts of fructose as carbohydrates. Hexosamines were isolated from the lens, glycoproteins--from the blood serum, and their turnover was studied. A drastic deceleration of hexosamine turnover in the lens was observed at high-fructose diets (20 and 40% of fuel value), while glycoprotein turnover in the blood plasma was not changed as compared to the control, glucose-6-phosphate dehydrogenase in red blood cells was decreased, insulin level was lowered, and glucose level in the blood serum rose insignificantly. It has been suggested that fructose may be cataractogenic in animals.