FK506 increases permeability in rat intestine by inhibiting mitochondrial function

Area of Science:

• Gastroenterology
• Pharmacology
• Cellular Metabolism

Background:

• The intestinal barrier, regulated by adenosine triphosphate (ATP), is crucial for normal physiological function.
• Compromised cellular metabolism can disrupt intestinal barrier integrity.
• FK506 is an immunosuppressant with potential effects on cellular energy pathways.

Purpose of the Study:

• To investigate the impact of FK506 on intestinal permeability in rats.
• To assess the effects of FK506 on enterocyte metabolic function.
• To determine the relationship between FK506, intestinal barrier function, and cellular energy metabolism.

Main Methods:

• Lewis rats were treated with varying doses of FK506 for 6 weeks.
• Intestinal permeability was measured using radiotracer excretion and Ussing chamber conductance.
• Enterocyte metabolic function was evaluated by measuring ATP levels and CO2 release from glucose and pyruvate.

Main Results:

• FK506 administration resulted in a dose-dependent decrease in weight gain and increased intestinal permeability.
• Impaired mitochondrial function led to reduced ATP levels and CO2 release in enterocytes.
• No significant changes were observed in plasma creatinine or urinary output.

Conclusions:

• FK506 treatment dose-dependently increases intestinal permeability in rats.
• FK506 diminishes the small intestine's capacity to utilize glucose for energy production.
• These findings highlight FK506's adverse effects on intestinal barrier integrity and metabolic function.