Quantification of Tyrosine Hydroxylase mRNA

The main biochemical characteristic of Parkinson’s disease (PD) is reduction of the neurotransmitter dopamine and the dopamine-synthesizing enzyme system, including tyrosine hydroxylase (TH, tyrosine 3-monooxygenase, EC 1.14.16.2) and tetrahydrobiopterin (BH₄ co-factor, in nigrostriatal neurons (1 ). The deficiency in dopamine-synthesizing enzymes is accompanied by cell loss, which is thought to be caused by unknown exogenous environmental factors as well as endogenous genetic factors.