Dopamine plays a crucial role in various physiological processes, especially in the context of movement disorders like Parkinson’s disease and Parkinsonian Multiple System Atrophy (MSA). Understanding dopamine’s role within the broader category of catecholamines is essential for comprehending its impact on the body. Catecholamines are a group of chemicals that include dopamine, norepinephrine, and epinephrine, all of which are derived from the amino acid tyrosine. Tyrosine serves as a precursor not only for catecholamines but also for thyroid hormones, establishing a connection between thyroid function and dopamine production.
In an ideal scenario, the body would evenly distribute tyrosine for both thyroid hormone production and dopamine synthesis. However, under conditions of high stress, the body prioritizes survival by diverting more tyrosine toward producing norepinephrine and epinephrine, the neurotransmitters involved in the stress response of the sympathetic nervous system. This shift can reduce the availability of tyrosine for dopamine production, potentially leading to movement disorders. The conventional understanding is that damage to the substantia nigra in the brain results in reduced dopamine production, leading to Parkinson’s and similar conditions. Consequently, patients are often treated with L-dopa to increase dopamine levels.
However, another factor could be the body’s response to stress, which might be driving the conversion of L-dopa directly to norepinephrine and epinephrine, bypassing dopamine production. This response is not an error but rather the body’s way of ensuring survival during high stress. By reducing stress and the body’s allostatic load, it may be possible to allow more tyrosine to contribute to dopamine production, potentially alleviating symptoms of movement disorders. Therefore, managing stress is not only crucial for overall health but also for improving outcomes in patients with movement disorders.
