Effects of New Endogenous Nonprotein Amino Acids, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic Acid Derivatives, on Behavior of Mice

Several 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acids were synthesized and found to have a transiently increasing effect on the locomotor activity of mice after peripheral injection. Three of the active compounds were detected in the brain after intraperitoneal administration. Two of them, the 7-hydroxy and 7-hydroxy-6-methoxy derivatives, were found as endogenous compounds in untreated rat brain and may play a physiological role. The effects of some of these compounds on the level of various endogenous amines, amino acids and metabolites were examined.