Uptake of glycine by human kidney cortex.
The transport of glycine was investigated in histologically normal adult human kidney cortical slices. Uptake occurs against a gradient and shows concentration dependence. Kinetic analysis reveals two systems for transport of glycine with apparent transport Km values of 0.511 and 34.2 mM. Glycine transport on the high-Km system is competitively inhibited by 50 mML-proline. Transport inhibition on the low-Km system could not be directly evaluated, but on theoretic grounds appears not to be inhibited by L-proline or hydroxyproline. Alpha-aminoisobutyric acid, valine, and thioproline are also shown to inhibit glycine uptake. Low medium sodium or anaerobic incubation depress the uptake of glycine. These observations are consistent with previous reports of glycine transport in rat kidney and support the proposals for the mechanism of familial iminoglycinuria based on in vivo investigations.
D000328:Adult; D000621:Aminoisobutyric Acids / Q000494:pharmacology; D000693:Anaerobiosis; D001692:Biological Transport; D005998:Glycine / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D006909:Hydroxyproline / Q000494:pharmacology; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000378:metabolism*; D007700:Kinetics; D011392:Proline / Q000494:pharmacology*; D012964:Sodium / Q000494:pharmacology; D014633:Valine / Q000494:pharmacology
D000621:Aminoisobutyric Acids; D011392:Proline; D012964:Sodium; D014633:Valine; D006909:Hydroxyproline; D005998:Glycine