PT  - JOURNAL ARTICLE
AU  - S. Spector
AU  - A. Sjoerdsma
AU  - S. Udenfriend
TI  - BLOCKADE OF ENDOGENOUS NOREPINEPHRINE SYNTHESIS BY α-METHYL-TYROSINE, AN INHIBITOR OF TYROSINE HYDROXYLASE
DP  - 1965 Jan 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 86--95
VI  - 147
IP  - 1
4099  - http://jpet.aspetjournals.org/content/147/1/86.short
4100  - http://jpet.aspetjournals.org/content/147/1/86.full
SO  - J Pharmacol Exp Ther1965 Jan 01; 147
AB  - Repeated administration of the tyrosine hydroxylase inhibitor, α-methyl-tyrosine to guinea pigs decreased catecholamine levels in brain stem, caudate nucleus, heart and spleen to undetectable levels. Serotonin was unaffected. That the catecholamine decrease was a consequence of inhibition of tyrosine hydroxylase was shown by the following: tissue concentrations of norepinephrine failed to rise following monoamine oxidase inhibition and decarboxylase inhibitors failed to block the α-methyl-tyrosine effect; the conversion of tyrosine-C14 to norepinephrine was inhibited whereas that from dopa-H3 was not; and there was a normal uptake of exogenous norepinephrine by heart and spleen in animals pretreated with α-methyl-tyrosine. Preliminary studies of the pharmacologic consequences of blockade of norepinephrine synthesis indicate impairment of motor activity and mild sedation in cats and guinea pigs and a reduction of the tyramine and norepinephrine pressor responses in guinea pigs and rats. The Williams & Wilkins Comapny