[Elastase-induced hyperfunction of submucous glands develops independent of elastase-induced emphysema]

Area of Science:

• Pulmonary Medicine
• Histology
• Biochemistry

Background:

• Pancreatic elastase is implicated in lung tissue degradation.
• Submucosal glands and goblet cells play crucial roles in airway mucus secretion and clearance.

Purpose of the Study:

• To investigate the effects of pancreatic elastase on tracheal submucosal glands and goblet cells in ferrets.
• To determine if elastase induces structural and functional changes in the airways independent of emphysema.

Main Methods:

• Male ferrets received intratracheal and intrapulmonary instillations of pancreatic elastase or control solutions over 15 days.
• Chest x-rays were taken periodically.
• Lung explants were analyzed for mean linear intercept (emphysema assessment).
• Tracheal sections were examined for goblet cell density, glandular structure, and function using quantitative histology and autoradiography.

Main Results:

• No emphysema was observed up to day 39.
• Significant structural changes in submucosal glands: decreased serous glands (S), increased mucous glands (M), and a reduced S/M ratio (p=0.05).
• Increased mucus synthesis (radioactive sulfur turnover, p=0.001) and goblet cell hyperplasia (p=0.05) were observed.

Conclusions:

• Pancreatic elastase induces significant structural and functional changes in tracheal submucosal glands.
• Elastase causes goblet cell hyperplasia, indicating increased mucus production.
• These airway changes occur independently of emphysema development.