Norepinephrine Synthesis from Tyrosine-C14 in Isolated Perfused Guinea Pig Heart

Science  29 Mar 1963:
Vol. 139, Issue 3561, pp. 1299-1301
DOI: 10.1126/science.139.3561.1299


The isolated, perfused guinea pig heart contains all the catalysts required to form norepinephrine from the dietary precursor, tyrosine. The conversion of tyrosine-C 14 to norepinephrine in the perfused heart occurred at a rate comparable to that estimated for this conversion in vivo. To account for the maintenance of norepinephrine stores in the normal heart, it is not necessary to postulate that the hormone is extracted from the blood.