The characteristics of arginine transport by rat cerebellar and cortical synaptosomes

• Published in: Neurochemical research 1996-12, Vol.21 (12), p.1539-1546
• Main Authors: ALDRIDGE, C. R, COLLARD, K. J
• Format: Article
• Language: English
• Subjects: Ammonium Chloride - pharmacology; Animals; Arginine - analogs & derivatives; Arginine - metabolism; Arginine - pharmacology; Biochemistry and metabolism; Biological and medical sciences; Biological Transport; Calcium - metabolism; Central nervous system; Cerebellum - metabolism; Cerebral Cortex - metabolism; Enzyme Inhibitors - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Kinetics; Nitric Oxide Synthase - antagonists & inhibitors; Potassium - pharmacology; Rats; Rats, Wistar; Sodium - pharmacology; Sodium Acetate - pharmacology; Synaptosomes - metabolism; Tritium; Vertebrates: nervous system and sense organs
• ISSN: 0364-3190; 1573-6903
• DOI: 10.1007/bf02533103

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.