Norepinephrine and 3,4-Dihydroxy-Phenethylamine Turnover in Guinea Pig Brain in vivo

Science  18 Oct 1963:
Vol. 142, Issue 3590, pp. 394-396
DOI: 10.1126/science.142.3590.394


By administering C14-la-beled tyrosine or H3-labeled 3,4-dihy-droxyphenylalanine to guinea pigs it has been possible to achieve sufficient labeling of the norepinephrine and dopamine in the brain to permit measurement of their turnover rates. The half-life of brain dopamine was about 2.5 hours. The half-life of norepinephrine was about 4 hours, suggesting a rate of synthesis of at least 0.03 to 0.04, µg/g per hr or 2.4 µg/day for the whole guinea pig brain.