What is the Difference Between L Dopa and Dopamine

The key difference between L Dopa and dopamine is that L Dopa is a precursor to neurotransmitters such as dopamine, norepinephrine, and epinephrine, while dopamine is a neuromodulatory molecule or neurotransmitter that plays several important roles in the brain cells.

Neuromodulators in the brain are substances that do not directly activate ion-channel receptors but that act together with neurotransmitters. They are a subset of neurotransmitters. These neuromodulators increase the excitatory or inhibitory responses of the receptors. The major neuromodulators present in the brain are dopamine, serotonin, acetylcholine, histamine, norepinephrine, nitric oxide, and several neuropeptides. These neuromodulators enhance the quality of life in individuals who suffer from severe chronic illnesses. L Dopa and dopamine are two associated molecules. L Dopa is a precursor to the neurotransmitter dopamine. Dopamine plays important roles, including memory, movement, motivation, mood, attention, and many other functions. In a disease like Parkinson’s, dopamine level substantially decreases. Therefore, L Dopa can be used to enhance the dopamine level in the human body.

CONTENTS

1. Overview and Key Difference
2. What is L Dopa 
3. What is Dopamine
4. Similarities – L Dopa and Dopamine
5. L Dopa vs Dopamine in Tabular Form
6. Summary – L Dopa vs Dopamine

What is L Dopa?

L Dopa is a precursor to neurotransmitters such as dopamine, norepinephrine, and epinephrine. It is also called levodopa. L Dopa is an amino acid. It is made and used as part of the normal biology of some plants and animals. Humans and other animals make it via biosynthesis from the amino acid L tyrosine. Moreover, L Dopa itself mediates neurotrophic factors released by the brain and central nervous system. Neurotrophic factors are bi-molecules that support the growth, survival, and differentiation of both developing and mature neurons.

L Dopa can be manufactured for several pharmaceutical purposes. In its pure form, it is a psychoactive drug with INN levodopa. L Dopa is marketed under the trade names Sinemet, Pharmacopa, Atamet, and Stalevo. Furthermore, as a drug, it is used in clinical setups to treat Parkinson’s disease and dopamine-responsive dystonia. In fact, L Dopa is the best treatment for Parkinson’s disease. The side effects of using L Dopa are nausea, dizziness, headache, and sleepiness. L Dopa can also cause serious side effects such as confusion, hallucinations, delusions, agitation, and psychosis. In addition, L Dopa has a counterpart molecule that has opposite chirality known as D Dopa. However, the human body produces only one of these isomers, which is L Dopa. The enantiomeric purity of L Dopa can be analyzed by the determination of optical rotation or by chiral thin layer chromatography.

What is Dopamine?

Dopamine is a neuromodulatory molecule or neurotransmitter that plays several important roles in the brain cells. Dopamine is a type of catecholamine. Therefore, it is an organic chemical and a member of the catecholamine and phenethylamine families. Dopamine is normally an amine that is produced by removing a carboxyl group from a molecule of its precursor chemical known as L Dopa. L Dopa is generally synthesized by the brain and kidneys in humans. Dopamine is also synthesized in plants and most animals.

In the brain, dopamine works as a neurotransmitter. A neurotransmitter is an organic chemical released by neurons to send signals to other neurons. Normally, neurotransmitters are synthesized in specific regions of the brain but affect many other regions. Furthermore, dopamine plays a vital role in many important functions of the body, including movement, memory, pleasurable rewards, and motivation. The indication symptoms of low dopamine levels are memory loss, unhappiness, sleep problems, and concentration problems. The indication symptoms of high dopamine levels are poor impulse control, euphoria, aggression, and temper.

High or low levels of dopamine are associated with several mental health conditions. The diseases associated with low levels of dopamine include Parkinson’s disease, Attention deficit hyperactivity disorder (ADHD), and Restless legs syndrome. Mania, obesity, and addiction are the disease conditions associated with high levels of dopamine. Side effects of dopamine drugs are anxiety, shortness of breath, irregular heartbeats, headaches, chills, and conditions such as Parkinson’s disease, ADHD, addiction, and schizophrenia.

What are the Similarities Between L Dopa and Dopamine?

• L Dopa and dopamine are two associated molecules.
• L Dopa is a precursor to the neurotransmitter dopamine.
• Both are organic molecules.
• Both molecules can be found in plants, other animals, and humans.
• Decreased levels of these molecules can cause particular diseases in humans.
• High levels of L dopa and dopamine lead to different disorders.
• Both are utilized as treatments for Parkinson’s disease.

What is the Difference Between L Dopa and Dopamine?

L Dopa is a precursor to neurotransmitters such as dopamine, norepinephrine, and epinephrine, while dopamine is a neuromodulatory molecule or neurotransmitter that plays several important roles in the brain cells. Thus, this is the key difference between L Dopa and dopamine. Furthermore, L Dopa is an amino acid, while dopamine is an amine.

The below infographic presents the differences between L Dopa and dopamine in tabular form for side-by-side comparison.

Summary – L Dopa vs Dopamine

L Dopa and dopamine are two associated molecules. Both molecules can be identified in plants, other animals, and humans. Together they play vital roles in nerve communication. L Dopa is a precursor to neurotransmitters such as dopamine, norepinephrine, and epinephrine, while dopamine is a neuromodulatory molecule or neurotransmitter that plays several important roles in the brain cells. So, this summarizes the difference between L Dopa and dopamine.

Reference:

1. “L-DOPA.” An Overview | ScienceDirect Topics.
2. “Dopamine: What It Is, Function & Symptoms.” Cleveland Clinic.

Image Courtesy:

1. “L-DOPA-to-dopamine” By Mys 721tx – Own work (CC0) via Commons Wikimedia
2. “Dopamine function before and after antipsychotics” By Mark v1.0 – Own work (CC BY-SA 4.0) via Commons Wikimedia