The characteristics of arginine transport by rat cerebellar and cortical synaptosomes.
The uptake of L-[3H]arginine into synaptosomes prepared from rat cerebellum and cortex occurred by a high-affinity carrier-mediated process. The uptake of arginine appeared to be potentiated by removal of extracellular Na+, inhibited by high levels of extracellular K+, but not by depolarization with veratridine or 4-amino pyridine. The effect of Na+ removal or K+ elevation did not seem to be due to changes in intracellular Ca2+ or pH. In both brain regions, uptake was significantly inhibited by L-arginine, L-lysine, L-ornithine, and L-homoarginine, but not by D-arginine nor L-citrulline. Uptake was also inhibited by NG-monomethyl-L-arginine acetate, but not by NG-nitro-L-arginine methyl ester nor NG-nitro-L-arginine except in the cortex at a concentration of 1 mM. The results indicate that the carrier system operating in synaptosomes showed many of the characteristics of the ubiquitous y+ system seen in many other tissues, although its apparent sensitivity to variations in extracellular Na+ was unusual.
Aldridge
C R
CR
Physiology Unit, School of Molecular and Medical Biosciences, University of Wales College of Cardiff, UK.
Collard
K J
KJ
D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000494:pharmacology; D019346:Sodium Acetate / Q000494:pharmacology; D013574:Synaptosomes / Q000378:metabolism*; D014316:Tritium
D004791:Enzyme Inhibitors; D000643:Ammonium Chloride; D014316:Tritium; D019346:Sodium Acetate; D001120:Arginine; D012964:Sodium; D019001:Nitric Oxide Synthase; D011188:Potassium; D002118:Calcium