Related Experiment Video
Updated: May 5, 2026
Absorption of Nasal and Bronchial Fluids: Precision Sampling of the Human Respiratory Mucosa and Laboratory Processing of Samples
Published on: January 21, 2018
Effect of nedocromil sodium on platelet-activating factor-induced airway responses
1Department of Thoracic Medicine, National Heart and Lung Institute, London, United Kingdom.
Abstract:
Platelet-activating factor (PAF) is one of the chemical mediators that may participate in the inflammatory process underlying asthma. It has been shown to produce a prolonged increase in airway responsiveness in several species, including humans. In humans the increase in bronchial reactivity peaks 3 days after inhalation and can last as long as several weeks. PAF may induce this response by recruiting eosinophils into the airways and activating them in the airway walls, with the subsequent release of basic proteins. This process causes eosinophils, which are rich sources of PAF, to release their contents and sets up a self-perpetuating cycle. Nedocromil sodium reduces the increased bronchial responsiveness of asthma and can prevent the development of increased responsiveness after inhaled PAF. The precise mechanism by which this result occurs is not known and requires further investigation.
Related Concept Videos
01:28Nitric Oxide Signaling Pathway
01:23Drugs Acting on Autonomic Ganglia: Stimulants
Ganglionic stimulants activate NM nicotinic receptors in autonomic ganglia, falling into two categories: nicotine mimetics [e.g., lobeline, dimethylpiperazine, tetramethylammonium] and muscarinic receptor agonists [e.g., muscarine, methacholine]. The first category's action is rapid and blocked by nicotinic receptor antagonists, while the second category's action is delayed and blocked by atropine-like agents. Nicotine, an alkaloid, affects the heart rate by stimulating...
01:26Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors...
01:28Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...
01:20Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
01:25Antiasthma Drugs: Mast Cell Stabilizers and Anti-IgE Drugs
Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without...