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What do You Mean by Histamine and Its Functions?

There are many biochemical compounds synthesized and stored in different cells of our physiology. One such naturally produced compound is histamine. This is a biochemical substance produced by the local cells in different tissues regarding an immune response. The production of this compound shows the presence and signifies the outcome of inflammation in an affected part of our body. In this section, we will learn about the definition of histamine meaning and its action. We will also discuss the function of histamine elaborately.

What is Histamine?

Every living organism has an immunological system that protects it from the different foreign particles or parasitic invasions. One such function of the immunological system is to produce histamine. Let us learn what this biochemical compound is.

The word ‘histamine’ means a biochemical compound secreted by the mast cells and basophils as a local response to an invasion of parasites or to protect cells from any foreign body. If we concentrate on the spit meaning of this word, we will find that it is an ‘amine’ generated in the cells or tissues or ‘histo’.

As the histamine meaning suggests, it is an amine compound that is formed due to the decarboxylation of histidine, an amino acid. In the animal kingdom, you will find myriads of compounds that match the prototypical formula of histamine. In fact, its presence has been noticed in insect venoms and plants. The name ‘amine’ comes from the derivation of ammonia (NH3).

How Histamine was Discovered?

In the year 1907, the histamine structure was recognized and synthetically manufactured in the laboratories. Its functions in human physiology were then established. This compound was found in the tissues when there is an immune response occurring due to the presence of a foreign body or microbe. This is the natural way of our body reacting against something unnatural entered in the tissues.

The function of histamine is to trigger the immune response actions and to make our body prepared for such incidents. Due to its formation, many cytological actions are initiated that help our body to cope with an immunological action and fight to eliminate the foreign body present in our system. This is why you can find histamine in different forms in almost all animals. Now that we have understood the histamine meaning, let us find out what its functions are.

Functions of Histamine

As we all know that histamine produced by an immune response in the local cells due to the presence of an unwanted particle or microbial invasion, let us find out what this biochemical compound does after secretion.

  • Vasodilatation

The primary histamine function is to dilate the blood capillaries and cause an escalation of blood flow. The blood pressure eventually reduces due to the enhanced lumen size of the blood vessels and vascular hyper-permeability. The endothelial cells of the capillaries bind with histamine to become dilated and become more permeable to the blood cells. In fact, the smooth muscles present in the blood vessels start to relax and cause a fall in blood pressure in the localized area.

  • Nasal Mucosal Effect

Due to the secretion of histamine, the nasal mucosal blood vessels become more permeable. It causes the excess passage of fluid escaping in the nasal passage. This happens when an allergic reaction triggers due to the occurrence of foreign bodies in the nasal mucosa. The role of histamine is to provide protection to the eyes and nose by secreting fluid produced due to the localized neural stimulation in this region.

  • Regulation of Sleep-Wake Cycle

Histamine is also responsible for the regulation of the sleep-wake cycle of a human being. It acts as a neurotransmitter connecting with the hypothalamus of a mammalian brain. When the neurological system of a human is asked what is the function of histamine, you will find that it is a part of the histamine system of a brain that controls the sleep and wake cycles of a human being. During wakefulness, this neurotransmitter is fired rapidly. When you are lethargic, the transmission reduces.

  • Gastric Acid Production and Release

The production and presence of histamine also cause the formation of gastric acid in the stomach. This biochemical stimulator escalates the absorption rate of water and carbon dioxide in the blood circulation system for the production of carbonic acid. This acid is then released into the stomach causing hyperacidity in the digestive system. This histamine action causes the escalation of acidity. Ranitidine is one of the prime antagonists that doctors prescribe to stop this uptake cycle.

  • Protection

The prime histamine function is to protect our body from foreign bodies, venom, or any kind of microbial invasion. It also protects us from convulsion, denervation super sensitivity, stress, and ischemic lesions. In fact, it also controls the learning and forgetting of memories.


Study the histamine structure and find out the meaning of the name first. Proceed to learn the basic functions of histamine in our body. It will become clearer to understand how this biochemical compound functions in our body.

FAQ (Frequently Asked Questions)

1.  What are the Histamine Effects on the Blood Circulation System?

Ans: The prime effect of histamine is the dilation of the blood vessels causing redness and swelling in an inflamed area. This happens when a particular area is under stress or shock due to injury or the presence of foreign bodies. Histamine acts as a local immune response stimulator thus helping our immune system to localize and eradicate the problems.

2.  How can You Summarize the Histamine Effects?

Ans: The best way to summarize the effects of histamine is to segregate its functions by considering the different body parts and organ systems. It will become a lot easier to understand how and where it functions and what happens due to its presence.

3.  Where Do You Find Histamine?

Ans: Histamine is found in almost all animals. In fact, you can also find it in a few plants and bacteria. Its simplistic chemical structure has immense use in different organ systems of complex animal physiology.