Leukotrienes

Definition

Leukotrienes are lipid compounds that are produced by immune cells and play a critical role in inflammatory responses, particularly in the context of allergic reactions and asthma. These mediators are derived from arachidonic acid and function by promoting bronchoconstriction, increasing vascular permeability, and attracting immune cells to sites of inflammation, thus influencing both innate immunity and allergic responses.

5 Must Know Facts For Your Next Test

1. Leukotrienes are primarily produced by immune cells such as mast cells, eosinophils, and basophils during the inflammatory process.
2. They are important mediators in asthma, where they can cause airway inflammation and hyperresponsiveness, leading to difficulty breathing.
3. Leukotriene receptor antagonists are used therapeutically to manage asthma symptoms by blocking the effects of leukotrienes on their receptors.
4. In addition to their role in asthma, leukotrienes are involved in various allergic conditions, including allergic rhinitis and anaphylaxis.
5. Leukotrienes can also influence the recruitment and activation of other immune cells, enhancing the overall inflammatory response during an immune reaction.

Review Questions

• How do leukotrienes contribute to the inflammatory response in innate immunity?
  • Leukotrienes play a significant role in the inflammatory response by promoting vasodilation and increasing vascular permeability, which allows immune cells to access tissues more effectively. They attract additional immune cells like eosinophils and neutrophils to the site of inflammation. This recruitment amplifies the innate immune response, facilitating the elimination of pathogens or allergens.
• Discuss the role of leukotrienes in asthma and how they impact airway function.
  • In asthma, leukotrienes contribute to airway inflammation by causing bronchoconstriction and increasing mucus production. This leads to narrowing of the airways, making it difficult for air to flow freely during breathing. The release of leukotrienes from activated mast cells exacerbates these symptoms, highlighting their importance in the pathophysiology of asthma and driving the need for treatments targeting these mediators.
• Evaluate the implications of targeting leukotriene pathways in managing allergic responses and asthma treatment strategies.
  • Targeting leukotriene pathways has significant implications for managing allergic responses and asthma. By using leukotriene receptor antagonists or inhibitors of their synthesis, healthcare providers can reduce inflammation and improve airway function in patients with asthma. This strategy not only alleviates acute symptoms but also addresses underlying chronic inflammation associated with allergies. As research continues, understanding these pathways may lead to more effective therapies that better control allergic conditions and improve patients' quality of life.

Related terms

Arachidonic Acid: A polyunsaturated fatty acid that is a key component of cell membrane phospholipids, serving as a precursor for the synthesis of leukotrienes and other eicosanoids.

Mast Cells: A type of immune cell that plays a crucial role in allergic reactions, releasing histamine and leukotrienes upon activation.

Cysteinyl Leukotrienes: A subgroup of leukotrienes, including LTC4, LTD4, and LTE4, that are particularly potent in inducing bronchoconstriction and promoting inflammation in asthma.