High and low affinity transport of L-arginine in rat brain synaptosomes.
The uptake of L-arginine into purified rat brain synaptosomes was investigated with respect to time and various concentrations of L-[3H]arginine. Specific uptake was found to be linear with time for up to 5 min of incubation at 37 degrees C. Electrolytes, including sodium chloride, potassium chloride, magnesium chloride and calcium chloride, inhibited uptake of 3 microM L-arginine, and the inhibitory effect increased with increased electrolyte concentration under constant osmolarity. It was found that L-arginine was transported into synaptosomes by two uptake components--a high affinity component (3.5 microM) and a low affinity component (100 microM). These two components were similar to the Ly+ system because of their extreme sensitivity to inhibition by L-lysine and L-ornithine but were distinguishable from each other by kinetic analysis of the uptake data and by their relative sensitivity to inhibition by several amino acids.
D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002122:Calcium Chloride / Q000494:pharmacology; D002540:Cerebral Cortex / Q000378:metabolism*; D007700:Kinetics; D015636:Magnesium Chloride / Q000494:pharmacology; D008297:Male; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D000596:Amino Acids; D015636:Magnesium Chloride; D012965:Sodium Chloride; D011189:Potassium Chloride; D001120:Arginine; D002122:Calcium Chloride