Tyrosine-derived catecholamines, including 3,4-dihydroxyphenylalanine (DOPA), dopamine and norepinephrine are important stress hormones. Stress increases tyrosine hydroxylase (TH) activity and biosynthesis, which is known to affect the adrenergic nervous system. TH has a large molecular diversity, resulting from differential splicing of its mRNA, which is tissue specific and can end in long-term changes in the enzyme activity. Morever, it affects the availability of neuro transmitter matters at some synapses. DOPA, dopamine, norepinephrine and epinephrine are synthesized in the catecholamine pathway. Chromaffin cells in the adrenal medulla release catecholamines. Both synthesis and release of catecholamines rise in chromaffin cells as the end of the increase in TH activity and TH mRNA
Author(s): Zeliha Selamoglu