EFFECT OF ARTERIAL-PORTAL GLUCOSE GRADIENTS AND PHLORHIZIN ON BILE GLUCOSE-LEVELS IN PERFUSED-RAT-LIVER

1. Bivascular perfused rat liver was used to study the effects of hepa tic artery-portal vein glucose gradients and the effects of phloridzin on bile glucose levels. 2. Bile glucose levels were examined when glu cose concentrations in the hepatic artery (HA) and portal vein (PV) in flows were equal. When the concentration of perfusate glucose was 10 m M, bile glucose remained stable at less than 0.075 mM; when perfusate glucose exceeded approximately 16.0 mM, bile glucose increased rapidly ; when 1.6 mu M phloridzin and 10.0 mM glucose were co-infused, phlori dzin entered rapidly into bile and settled at a steady-state concentra tion of 0.45 +/- 0.04 mM, and bile glucose increased to 3.75 +/- 0.14 mM. 3. During perfusion of HA-PV glucose gradients such that HA glucos e was higher than that in the sinusoids, bile glucose levels were incr eased compared with their levels when HA glucose was equivalent to tha t in the sinusoids. The converse was also demonstrated 4. The results regarding phloridzin-sensitive glucose transport in the biliary tree o f the rat were consistent with those documented in vivo. The finding t hat bile glucose levels altered in a manner parallel to that of the HA , although the total inflow remained unchanged, strongly indicated tha t HA,glucose level, rather than that of the PV, performs an important role in control of bile glucose levels.