Small intestinal absorption during endotoxemia in swine

Area of Science:

• Gastroenterology
• Physiology
• Pathology

Background:

• Systemic endotoxemia, often caused by Gram-negative bacterial infections, can lead to multi-organ dysfunction.
• The small intestine plays a crucial role in nutrient and water absorption, making it vulnerable to systemic inflammatory insults.

Purpose of the Study:

• To investigate the impact of endotoxemia on the absorptive function of the distal ileum in a swine model.
• To correlate functional changes in intestinal absorption with histological alterations following lipopolysaccharide (LPS) administration.

Main Methods:

• Adolescent Yorkshire swine with Thiry-Vella fistulae in the distal ileum were used.
• Absorption of water, electrolytes (Na+, Cl-), and glucose was measured using radiolabeled polyethylene glycol (14C-PEG) under basal, acute LPS, and chronic LPS conditions.
• Ileal tissue was examined histologically at various time points post-LPS.

Main Results:

• Acute LPS administration transiently reduced water, Na+, and Cl- absorption, with recovery within hours.
• Glucose absorption showed a similar trend but lacked the early transient recovery.
• Twenty-four hours post-LPS, water, Na+, and Cl- absorption were significantly decreased below baseline, accompanied by ileal epithelial inflammation and villous atrophy.

Conclusions:

• Endotoxemia adversely affects small intestinal absorption of water, electrolytes, and glucose in the immediate and early post-insult periods.
• Histological evidence of epithelial injury, including inflammation and villous atrophy, occurs secondary to endotoxemia.
• The observed histological damage to the ileum demonstrates reversibility, suggesting potential for recovery of intestinal function.