Related Experiment Video
Updated: Aug 11, 2026
10:20
In vitro Measurements of Tracheal Constriction Using Mice
Published on: June 25, 2012
An expectorant, stepronin, reduces airway secretion in vitro
1First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Respiration; International Review of Thoracic Diseases
|January 1, 1994
Summary
Stepronin (SPN) and its metabolite thenoic acid (TA) inhibit airway secretion. They reduce chloride secretion from epithelial cells and mucus glycoprotein release from submucosal glands in vitro.
Area of Science:
- Pharmacology
- Respiratory Physiology
Background:
- Stepronin (SPN) is an expectorant, with thenoic acid (TA) as its metabolite.
- Airway secretion involves epithelial ion transport and mucus glycoprotein release.
Purpose of the Study:
- To investigate the effects of SPN and TA on canine tracheal bioelectric parameters.
- To assess the impact of SPN and TA on feline tracheal mucus glycoprotein secretion.
Main Methods:
- Ussing chamber technique to measure potential difference (PD), short circuit current (SCC), and conductance (G) in tracheal epithelium.
- Measurement of [3H]-glycoconjugates to quantify mucus glycoprotein secretion from isolated glands.
Main Results:
- SPN and TA inhibited isoproterenol-evoked PD and SCC in tracheal epithelium without altering conductance.
- Both SPN and TA significantly reduced mucus glycoprotein secretion from isolated glands, even when stimulated by methacholine.
Conclusions:
- SPN exerts its expectorant effect by inhibiting airway secretion.
- The mechanism involves reducing both epithelial chloride secretion and submucosal gland mucus glycoprotein release.
Related Concept Videos
01:11Direct-Acting Cholinergic Agonists: Therapeutic Uses
Direct-acting cholinergic agonists have many therapeutic uses in various medical fields. Choline esters, including acetylcholine, have limited clinical utility due to their non-selectivity and short duration of action. Still, acetylcholine and carbachol are applied topically during ophthalmologic surgery to induce miosis. Pilocarpine, a muscarinic and ganglionic stimulator, effectively treats open-angle glaucoma and alleviates xerostomia and dry mouth caused by radiotherapy or Sjögren syndrome.
01:16Drugs Used in Upper Respiratory Disorders: Overview
Upper respiratory tract disorders, including viral infections and allergic rhinitis, cause significant discomfort and disrupt daily life. Managing these conditions involves a variety of drugs, such as antihistamines, intranasal steroids, decongestants, antitussives, expectorants, and mucolytics. Specific examples of drugs in each category are provided.
Antihistamines (e.g., Benadryl) block histamines from binding. Histamines are chemicals released during an allergic reaction in the body. As a...
Antihistamines (e.g., Benadryl) block histamines from binding. Histamines are chemicals released during an allergic reaction in the body. As a...
01:23Upper Respiratory Drugs: Antitussives, Expectorants, and Mucolytics
Respiratory symptoms, such as congestion and cough, commonly accompany respiratory tract conditions. Various medications, such as antitussives, expectorants, and mucolytics, play crucial roles in providing relief.
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by anesthetizing...
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by anesthetizing...
01:26Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Sputum studies are a critical part of diagnosing and treating numerous respiratory conditions. These studies involve obtaining sputum samples for analysis to identify pathogenic organisms and assess the presence of abnormal cells indicative of malignant conditions. This lesson will delve into three fundamental sputum studies: Gram Stain, Cytology, and Acid-fast Smear and Culture.
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
01:20Sputum Studies II: Culture and Sensitivity
Description
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...