Functional redundancy of glucose acquisition mechanisms in the hindgut of Pacific hagfish (Eptatretus stoutii)

摘要: This study examined the mechanisms of glucose acquisition in hindgut Pacific hagfish (Eptatretus stoutii) using vitro gut sac techniques. The intestine was determined to have capacity digest maltose into along entirety tract, including foregut. Glucose uptake biphasic and consisted a high-affinity, low-capacity concentration-dependent component conforming Michaelis-Menten kinetics (Km 0.37mM, Jmax 8.48nmol/cm2/h) as well diffusive component. There no observed difference flux rate length intestine, similar other nutrients investigated intestine. A reduced sodium (<1mM) environment did not result change rates, likely due functional redundancy transporters. effect phloretin, yet glucose-linked transporter (SGLT)-specific inhibitor phlorizin significantly at all concentrations tested (0.0001-1mM). Additionally, (GLUT) cytochalasin b transport rates. effects these pharmacological inhibition experiments suggest presence multiple types proteins. clarifies strategies used by acquire provides insight evolution such systems early-diverging vertebrates.