Otogeny of sugar transport in fetal rat kidney.
Concentration of alpha-methyl-D-glucopyranoside (alpha-MG) by kidney slices of rat fetuses increases during the studied period of gestation from day 18 until day 21 (last day of gestation). Glucoside transport is inhibited by phloridzin, D-glucose and D-galactose. Concentration dependence, over a substrate range from 0.01 to 0.2 mM, was studied on day 21: alpha-MG transport obeys a saturation kinetic with a low apparent Km (0.22 mM); D-glucose inhibition is of competitive nature (apparent Ki: 0.47 mM). Sodium dependence is demonstrated on day 21 of gestation: the phloridzine-sensitive transport, entirely inhibited in Na+-free medium, is enhanced when medium Na+ concentration increases from 0 to 143 mEq/l (Krebs-Ringer buffer concentration); further increase of Na+ concentration has no effect.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D005333:Fetus / Q000378:metabolism; D005690:Galactose / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D066298:In Vitro Techniques; D007668:Kidney / Q000502:physiology*; D008757:Methylglucosides / Q000378:metabolism*; D008759:Methylglycosides / Q000378:metabolism*; D010695:Phlorhizin / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000494:pharmacology
D008757:Methylglucosides; D008759:Methylglycosides; D012964:Sodium; D010695:Phlorhizin; D005947:Glucose; D005690:Galactose