title: Competitive kinetics in the inhibition of sugar intestinal transport by phlorizin, in vivo.
abstract: Kinetics of sugar transport inhibition by phlorizin in rat intestine has been studied in vivo. Jejunum lumen was perfused during a series of successive 1 minute periods of absorption. Total sugar absorption was assumed to be the sum of a mediated transport component plus a passive one persisting in the presence of 5 X 10(-4) M phlorizin. The values of transport rates, corrected in this way, showed Michaelis-Menten kinetics and proved that inhibition of D-glucose, D-galactose and 6-deoxy-D-glucose transport by low concentrations of phlorizin (5 X 10(-6) M) displays a typical competitive kinetics (apparent Ki = 4-10 X 10(-6) M) as had been long before reported from in vitro experiments.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001693:Biological Transport, Active / Q000187:drug effects; D003847:Deoxyglucose / Q000378:metabolism / Q000031:analogs & derivatives; D005260:Female; D005690:Galactose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects*; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010695:Phlorhizin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D003847:Deoxyglucose; D010695:Phlorhizin; D005947:Glucose; C037904:6-deoxyglucose; D005690:Galactose