Effect of tyrosine on brain catecholamine turnover in reserpine-treated rats.
The injection of reserpine [2.5 mg/kg, intraperitoneally (i.p.)] increased brain concentration of tyrosine and of the major catecholamine metabolites, 3-methoxy-4-hydroxy-phenylethylene--glycol-sulfate (MHPG-SO4) in the rat. In reserpine-treated animals, tyrosine administration (200 mg/kg, i.p.) caused further increases in brain tyrosine, DOPAC, and HVA, but not in brain MHPG-SO4. The increases in DOPAC and HVA levels were observed in a dopaminergic brain region (the corpus striatum) and a noradrenergic region (the cerebellum). These results support previous observations that catecholamine synthesis and release in both dopaminergic and noradrenergic neurons can depend in part upon brain tyrosine levels.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism*; D004347:Drug Interactions; D006719:Homovanillic Acid / Q000032:analysis; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000032:analysis; D009638:Norepinephrine / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012110:Reserpine / Q000008:administration & dosage*; D014443:Tyrosine / Q000008:administration & dosage / Q000032:analysis
D002395:Catecholamines; C021208:isohomovanillic acid; C021209:isoMHPG; D014443:Tyrosine; D008734:Methoxyhydroxyphenylglycol; D012110:Reserpine; D009638:Norepinephrine; D006719:Homovanillic Acid