title: Enhancement of rat brain catecholamine synthesis by administration of small doses of tyrosine and evidence for substrate inhibition of tyrosine hydroxylase activity by large doses of the amino acid.
abstract: Rat brain catecholamine synthesis is enhanced by small doses of tyrosine, but not by doses of 50mg/kg body wt. and above. It is suggested that these latter doses overcome the above enhancement by causing a substrate inhibition of tyrosine hydroxylase activity.
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D002395:Catecholamines / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014443:Tyrosine / Q000097:blood / Q000494:pharmacology*; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors*
chemical_list: D002395:Catecholamines; D014443:Tyrosine; D014446:Tyrosine 3-Monooxygenase