Phloretin inhibition of glucose transport by the tapeworm Hymenolepis diminuta: a kinetic analysis.

Phloretin non-competitively inhibits glucose and methionine absorption by Hymenolepis diminuta (Ki = 0.24 and 1.48 mM, respectively). Inhibition of glucose transport by phloretin is reversible. Phloretin and phlorizin binding sites on the surface of H. diminuta are distinct. Phloretin does not inhibit Na+ transport independent of glucose transport in H. diminuta. The data suggest that phloretin inhibits absorptive functions across the surface of H. diminuta via non-specific binding sites associated with the lipid portion of the worm outer membrane.