Glutamine uptake by rat renal basolateral membrane vesicles

Abstract

The presence of a sodium-dependent, saturable uptake process is described in basolateral membranes of rat renal cortex for L-glutamine. Concentration-dependence studies indicate the presence of multiple transport systems with Km1 of 0.032 mM and V1 of 0.028 nmol/mg of protein per min, and Km2 of 17.6 mM and V2 of 17.6 nmol/mg of protein per min. Lysine completely inhibits the high-affinity, low-capacity Km system and partially inhibits the low-affinity, high-capacity system. Cystine and other dibasic amino acids also affect glutamine uptake.