Tyrosine Hydroxylase Deficiency and Brain Disorders

Mon, 03/18/2013 - 11:12

 Tyrosine hydroxylase catalyzes the rate-limiting step in the biosynthesis of the catecholamines dopamine, norepinephrine, and epinephrine. A hallmark of Parkinson's disease is the loss of dopaminergic neurons in the substantia nigra. Mutations in cases of autosomal recessive dopa-responsive dystonia and infantile Parkinsonism have also been identified recently. TH deficiency is also known to be associated with a broad phenotypic spectrum ranging from TH-deficient dopa-responsive dystonia at the mild end to a levodopa-unresponsive infantile Parkinsonism or progressive infantile encephalopathy phenotype. These infants are more difficult to treat and unusually prone to side effects (dyskinesias and gastrointestinal side effects) of levodopa therapy (1).

IF analysis of Tyrosine Hydroxylase in retina tissue. IF analysis of Tyrosine Hydroxylase in retina tissue.

Human TH deficiency has been documented to lead towards neurological disorders, apparently leaving other organs unaffected. An explanation for this observation might be that the brain is the most vulnerable organ, already severely affected by relatively minor changes in the TH levels. TH deficiency is a severe but often very treatable neurometabolic disorder resulting from cerebral catecholamine deficiency. The diagnosis of THD relies on clinical suspicion and the analysis of CSF metabolites (2). In Vitro studies using dopamergenic cell line and manganese (Mn) exposure causes manganism, a neurological disorder similar to Parkinson’s disease. Results from this study demonstrated that low dose Mn exposure impairs TH activity in dopaminergic cells through activation of PKCδ and PP2A activity as determined using anti-TH antibodies and phosphorylated anti-TH antibodies suggesting the importance of TH in neurological disorders (3).

  1. PMID: 20301610
  2. PMID: 20430833
  3. PMID: 21310168


Novus Biologicals offers many Tyrosine Hydroxylase reagents for your research needs including:


Blog Topics