Hymenolepis diminuta: membrane transport of glucose and beta-methylglucoside

Absorption kinetics of ¹⁴C]glucose and β-methyl-¹⁴C]glucoside in Hymenolepis diminuta are reported. β-Methylglucoside (βMG) is a pure competitive inhibitor of ¹⁴C]glucose transport and has kinetic parameters, V_max and K_t, for transport similar to those reported for glucose. While absorbed ¹⁴C-βMG is not metabolized, transport of this glucose analog retains the general characteristics which have been established for glucose transport including: (1) Na⁺ dependence, (2) inhibition by K⁺, (3) sensitivity to phlorizin and various hexoses, (4) transport against an apparent concentration gradient, and (5) increase in worm water during accumulation. It is concluded that glucose and βMG are transported by the same system. The value of using βMG to study the mechanism of hexose transport and accumulation in H. diminuta is suggested.