Participation of the ring oxygen in sugar interaction with transporters at renal tubular surfaces.
The pulse-injection indicator-dilution technique in vivo has been used to study the interaction of 5-thio-D-glucose and methyl-beta-D-thiogalactopyranoside with renal tubular surfaces in dog kidney. (i) 5-Thio-D-glucose and methyl-beta-D-thiogalactopyranoside have nor antiluminal interaction. (ii) 37 +/- 5% of 5-thio-D-glucose is extracted at the luminal surface relative to simultaneously filtered creatinine. (iii) Luminal extraction of 5-thio-D-glucose is blocked by preloading with D-glucose and phlorizin. (iv) Methyl-beta-D-thiogalactopyranoside in contrast to D-galactose has not luminal interaction. It is concluded that 5-thio-D-glucose shares the glucose transporter at the luminal surface of the proximal tubule. The data also suggest that the ring oxygen participates in the interaction of pyranosides with luminal and antiluminal membrane carriers. At the luminal surface, its absence is quantitatively important while at the antiluminal surface it is apparently essential for the sugar-transporter interaction.
D000818:Animals; D001692:Biological Transport; D001786:Blood Glucose / Q000378:metabolism; D004285:Dogs; D005947:Glucose / Q000031:analogs & derivatives* / Q000378:metabolism; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008756:Methylgalactosides / Q000378:metabolism*; D008759:Methylglycosides / Q000378:metabolism*; D010695:Phlorhizin / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013862:Thiogalactosides / Q000378:metabolism*; D013865:Thioglycosides / Q000378:metabolism*
D001786:Blood Glucose; D008756:Methylgalactosides; D008759:Methylglycosides; D013862:Thiogalactosides; D013865:Thioglycosides; C009468:thiomethylgalactoside; C003002:5-thio-D-glucose; D010695:Phlorhizin; D005947:Glucose