Changes in the concentrations of tetrahydrobiopterin, the cofactor of tyrosine hydroxylase, in blood under physical stress and in depression.

ABSTRACT

This paper studies changes in the concentrations of tetrahydrobiopterin (BH4), the cofactor of tyrosine hydroxylase, in blood under physical stress and in depression. BH4 was found to be transiently released from the sympathetic nerves under severe physical stress but continuously released in depression with an increased oxidation rate of BH4 to B.