"Healed" experimental gastric ulcers remain histologically and ultrastructurally abnormal

Area of Science:

• Gastroenterology
• Histopathology
• Ultrastructural Biology

Background:

• Gastric ulcers are common, and their healing process is crucial for gastrointestinal health.
• Understanding the long-term structural integrity of healed gastric ulcer sites is essential for preventing recurrence.

Purpose of the Study:

• To evaluate the histologic and ultrastructural characteristics of gastric mucosa in healed acetic acid-induced gastric ulcers in rats.
• To determine if the gastric mucosa structure and cellular composition are fully restored after gross ulcer healing.

Main Methods:

• Acetic acid-induced gastric ulcers were created in Sprague-Dawley rats.
• Gastric wall specimens from healed ulcer areas were analyzed using light and transmission electron microscopy at various time points (2 weeks to 4 months).

Main Results:

• All healed ulcers showed re-epithelialization, but underlying mucosa had significant histologic and ultrastructural abnormalities.
• Two scar patterns were observed: thinner mucosa with increased connective tissue and poor glandular cell differentiation, or gastric gland ballooning with reduced vascular networks and poor glandular cell differentiation.
• These abnormalities persisted throughout the study period.

Conclusions:

• The subepithelial mucosa in healed gastric ulcers exhibits disorganized glandular and vascular structures, remaining histologically and ultrastructurally abnormal.
• These persistent abnormalities may compromise mucosal oxygenation, nutrient supply, and defense mechanisms.
• The observed structural deficits in healed gastric ulcer sites could be a contributing factor to ulcer recurrence.