The inhibitory effect of phlorhzin and phloretin on hexose transport in the liver

The inhibitory effect of phlorhzin on renal tubular glucose absorption has been known for a long time now. But its aglycone, phloretin is almost completely devoid of such an action in the kidney although it is more active than phlorhzin on sugar transport mechanism in human erythrocytes. The present investigation was designed to find out the effects of these two chemically related substances on hexose transport in the liver. The effect of 1mM phlorhzin or ImM phloretin on the transport of D-stereoisomers of glucose, galactose and fructose using the first pass extraction technique. It was found that phloretin was a better inhibitor of hexose transport in the liver. The difference between the effect of phlorhizin, and the phloretin was highly significant. The inhibitory pattern of the two chemical substances on the three hexoses indicate a discrimination between galactose transport and glucose or fructose transport in the liver.