The key difference between histidine and histamine is that histidine is an α amino acid used in the biosynthesis process of proteins while histamine is an amine that acts as a neurotransmitter for the brain, spinal cord, and uterus.
Histidine is an essential amino acid in humans. It is needed for growth and tissue repair. It is also needed for the maintenance of myelin sheaths that protect nerve cells. Histidine is required for blood cell manufacture, and it protects tissue against damages caused by radiation and heavy metals. Due to the action of the histidine decarboxylase enzyme, histidine metabolizes into histamine. Histamine is a neurotransmitter. It plays many roles in immunity, gastric secretion, and sexual function.
CONTENTS
1. Overview and Key Difference
2. What is Histidine
3. What is Histamine
4. Similarities – Histidine and Histamine
5. Histidine vs Histamine in Tabular Form
6. Summary – Histidine vs Histamine
What is Histidine?
Histidine is an α amino acid used in the biosynthesis of proteins. People use histidine as a medicine. It is essential for both infants and adults. It is encoded by the genetic codons CAU and CAC. Histidine contains an α amino group, a carboxylic group, and an imidazole side chain. In the physiological pH, histidine is classified as a positively charged amino acid. This amino acid was first isolated by the German physician Albrecht Kossel and Swedish chemist Sven Gustaf Hedin in 1896.
Figure 01: L-Histidine
L-histidine is an essential amino that is not synthesized in humans. Humans and other animals must ingest histidine by consuming histidine-containing proteins. Scientists have widely studied the biosynthesis of histidine in prokaryotes such as E. coli. Usually, histidine synthesis in E .coli involves eight gene products, and the process occurs in ten steps. The primary function of histidine in the body is to regulate and help metabolize trace elements such as copper, iron, zinc, manganese, and molybdenum. Moreover, it is used by the body to make specific hormones and metabolites that impact kidney function, the transmission of nerves, stomach secretions, and the immune system. It also impacts the repair and growth of tissue, production of blood cells, and protects nerves cells. Furthermore, histidine helps to form different enzymes and compounds such as metallothionein. Metallothionein protects the brain cells.
What is Histamine?
Histamine is an amine that acts as a neurotransmitter for the brain, spinal cord, and uterus. It is an organic nitrogenous compound involved in local immune responses, regulating physiological functions in the gut. Histamine was first discovered by English pharmacologist and physiologist Henry Dale in 1910. Since its discovery, histamine has been considered a local hormone. This is because it lacks a classic endocrine gland to secrete it. Moreover, histamine consists of an imidazole ring attached to an ethylamine chain.
Figure 02: Histamine
Histamine is normally involved in the inflammatory responses. Histamine has a central role as a mediator of itching. It also plays an important role in the immune response to foreign pathogens. Histamine is produced by basophils and mast cells that are found in connective tissues. It increases the permeability of the capillaries to white blood cells and some proteins. This allows them to engage with pathogens in the infected tissue.
What are the Similarities Between Histidine and Histamine?
- Histidine and histamine are organic compounds.
- Both compounds contain an imidazole group in the structure.
- They are very important for the nervous system and immune system of the body.
- Both compounds play important physiological functions.
What is the Difference Between Histidine and Histamine?
Histidine is an α amino acid that is used in the biosynthesis process of proteins, while histamine is an amine that acts as a neurotransmitter for the brain, spinal cord, and uterus. Thus, this is the key difference between histidine and histamine. Furthermore, the molecular formula of histidine is C6H9N3O2 while the molecular formula of histamine is C5H9N3.
The below infographic presents the differences between histidine and histamine in tabular form for side by side comparison.
Summary – Histidine vs Histamine
Histidine and histamine are organic compounds that are vital for the physiological functions of the body. Histidine is an α amino acid that is used in the biosynthesis process of proteins, while histamine is an amine that acts as a neurotransmitter for the brain, spinal cord, and uterus. So, this is the key difference between histidine and histamine.
Reference:
1. Fowler, Paige. “Histamines: What They Do, and How They Can Overreact.” WebMD.
2. Brosnan, Margaret E, and John T Brosnan. “Histidine Metabolism and Function.” The Journal of Nutrition, vol. 150, no. Supplement_1, 2020, https://doi.org/10.1093/jn/nxaa079.
Image Courtesy:
1. “L-Histidine physiological” By Vaccinationist – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Histamine 3D ball” By Jynto (talk) – Own work This image was created with Discovery Studio Visualizer. (CC0) via Commons Wikimedia