Tyrosine transport by membrane vesicles isolated from rat brain.
Tyrosine uptake by membrane vesicles derived from rat brain has been investigated. The uptake is dependent on an Na+ gradient ([Na+]outside greater than [Na+]inside). The uptake is transport into an osmotically active space and not a binding artifact as indicated by the effect of increasing the medium osmolarity. The process is stimulated by a membrane potential (negative inside) as demonstrated by the effect of the ionophores valinomycin and carbonyl cyanide m-chlorophenylhydrazone and anions with different permeabilities. Kinetic data show that tyrosine is accumulated by two systems with different affinities. Tyrosine uptake is inhibited by the presence of phenylalanine and tryptophan.
D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009550:Nigericin / Q000494:pharmacology; D009994:Osmolar Concentration; D051381:Rats; D012964:Sodium / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism*; D014634:Valinomycin / Q000494:pharmacology
D014634:Valinomycin; D014443:Tyrosine; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D012964:Sodium; D009550:Nigericin