Histamines are a type of protein stored in the body that are responsible for the identification and elimination of allergens and other foreign bodies. Usually, histamine effects work in three ways. First, histamine affects the rate of inflammation in the body, through both an increase in permeability of surrounding blood vessels, as well as through a release of cytokin cells. Histamine also commonly affects the amount and type of mucus production in the body. In addition, research has also found that histamine affects the smooth muscles in the body, which is one of the primary contributors to asthma attacks; tightening of the smooth muscles of the airway and a decrease in airflow to the lungs can be very serious, and even possibly life threatening.
One of the most common histamine effects on the body is inflammation. When histamines are released in a particular part of the body, they produce an increase in permeability in the surrounding blood vessels. This results in an increase in blood flow and immune cells, which leads to swelling. In addition, histamine exposure triggers the release of cytokin cells, which travel to the surrounding leukocytes and trigger an increase in swelling and inflammation in the affected body part.
Another common histamine effects include an increase in mucus production. In the body, there are two separate types of histamine receptors, commonly known as H1 and H2 receptors. During H1 receptor activation, an increase in mucus production occurs in an attempt to trap the allergen that is causing the histamine release. In contrast, during H2 activation, an increase in the thickness of the mucus produced by the body occurs. The body is trying to make it easier for foreign bodies and allergens to get trapped in the mucus and excreted.
Histamine can also serious effect the ability of smooth muscles in the body to function normally. Research has found that histamine's effect on these muscles is closely linked to asthmatic attacks. In most cases, when an allergen enters the body and a subsequent histamine release occurs, the surrounding smooth muscles contract in an attempt to allow histamines to function properly and aid in the excretion of the foreign particle from the body. When a foreign body enters the airway and the histamine effect begins to occur, the surrounding smooth muscles contract. This limits airflow to the lungs, and can result in an asthma attack.