Mouse Histamine (HIS) ELISA Kit

• Microplate reader with 450 nm wavelength filter
• Multichannel Pipette, Pipette, microcentrifuge tubes and disposable pipette tips
• Incubator
• Deionized or distilled water
• Absorbent paper
• Buffer resevoir

When carrying out an ELISA assay it is important to prepare your samples in order to achieve the best possible results. Below we have a list of procedures for the preparation of samples for different sample types.

Histamine is a biogenic amine that serves as a vital neurotransmitter and signaling molecule in the human body. It is involved in various physiological processes and plays a crucial role in the immune response. Histamine is synthesized and stored in mast cells and basophils, which are types of white blood cells found in tissues throughout the body. When histamine is released, it can trigger a range of effects, including vasodilation, increased vascular permeability, smooth muscle contraction, and stimulation of gastric acid secretion.

Histamine performs a wide range of functions in the body. It acts as a neurotransmitter in the central nervous system, playing a role in regulating sleep-wake cycles, appetite, and cognitive functions. In peripheral tissues, histamine functions as a potent mediator of allergic and inflammatory responses. It is involved in the immediate hypersensitivity reaction, contributing to the symptoms of allergies, such as itching, sneezing, and nasal congestion. Histamine also plays a crucial role in gastric acid secretion, regulating stomach acid levels and aiding in the digestion process.

Histamine is synthesized in the body through a two-step enzymatic process. The first step involves the decarboxylation of the amino acid histidine by the enzyme histidine decarboxylase (HDC), which removes a carboxyl group and forms histamine. This reaction takes place primarily in mast cells and basophils. The second step involves the enzymatic methylation of histamine by histamine N-methyltransferase (HNMT) in various tissues, including the liver, kidneys, and central nervous system, to form N-methylhistamine. These enzymes play a crucial role in regulating histamine levels and its subsequent physiological effects.

There are four known types of histamine receptors: H1, H2, H3, and H4. Each receptor subtype is associated with different physiological functions and is found in different locations within the body. When histamine binds to its respective receptor, it triggers a series of intracellular signaling pathways that lead to specific cellular responses. For example, activation of H1 receptors can cause smooth muscle contraction, increased vascular permeability, and allergic symptoms, while activation of H2 receptors stimulates gastric acid secretion. H3 and H4 receptors are mainly found in the central nervous system and immune cells, respectively, and are involved in regulating neurotransmitter release and modulating immune and inflammatory responses.

Once histamine is synthesized, it is stored in vesicles within mast cells and basophils. Upon activation by various triggers like allergens, physical trauma, or immune responses, these cells release histamine into the surrounding tissues. Histamine can then bind to its specific receptors (H1, H2, H3, and H4) located on various cells and tissues throughout the body, initiating specific physiological responses. After exerting its effects, histamine undergoes enzymatic degradation. The primary enzyme involved in histamine metabolism is diamine oxidase (DAO), which breaks down histamine into imidazole acetic acid, reducing its biological activity. Another enzyme, histamine N-methyltransferase (HNMT), also plays a role in metabolizing histamine by methylating it to form N-methylhistamine. These enzymatic processes help regulate histamine levels and prevent excessive histamine accumulation in the body.

Histamine's clinical significance is vast, with both therapeutic and pathological implications. Excessive histamine release or impaired histamine metabolism can lead to various allergic disorders, including allergic rhinitis, asthma, and urticaria (hives). Antihistamines are commonly used to alleviate these symptoms by blocking histamine receptors. Additionally, histamine is involved in gastric acid secretion, and abnormalities in histamine signaling can contribute to gastrointestinal disorders like peptic ulcers. Understanding the role of histamine and its receptors has led to the development of medications targeting specific receptor subtypes, providing effective treatments for conditions like gastric acid-related diseases and allergic reactions.

Histamine intolerance is a condition characterized by the body's inability to properly metabolize histamine. It occurs due to a deficiency or dysfunction of enzymes responsible for histamine breakdown. When histamine accumulates, it can cause symptoms similar to allergies, such as headaches, itching, digestive issues, and nasal congestion. Diagnosis involves evaluating symptoms and dietary elimination trials. Treatment focuses on reducing histamine levels by following a low-histamine diet and, in some cases, using supplements. Histamine intolerance is different from a true allergy, as it involves impaired histamine processing rather than an immune response.