ausblenden:
Schlagwörter:
Renal Brush Border; D-glucose and Phlorizin Binding; Sodium Dependence; Competitive Inhibition / Renaler Bürstensaum; Membranbindung von Phlorrhizin und D-Glucose; Kompetitive Hemmung; Natriumabhängigkeit
Zusammenfassung:
Glucose binding to the luminal cell membrane was studied in the isolated brush border of rat renal cortex by means of inhibition of phlorizin binding to a specific receptor site. This effect was reversible and stereospecific and fulfilled the criteria of fully competitive inhibition. Thus, the kinetic parameters of D-glucose binding to the same receptor could be derived. The affinity of the receptor to either substrate, phlorizin as well as D-glucose, increased with rising ambient sodium concentration while the number of binding sites remained unchanged. Other cations (K+, Ca++, Mg++) showed no effect on either parameter. The results of this study are in agreement with a model of transmembrane transport of glucose put forward by Crane.
