Biliary obstruction exacerbates the hepatic microvascular inflammatory response to endotoxin

Area of Science:

• Hepatology
• Microcirculation Physiology
• Sepsis Pathophysiology

Background:

• Gram-negative sepsis poses a significant risk for patients with obstructive jaundice.
• Hepatic microcirculation plays a critical role in liver function and sepsis response.

Purpose of the Study:

• To investigate the impact of chronic biliary obstruction on the hepatic microvascular response to endotoxin (lipopolysaccharide, LPS).
• To elucidate the mechanisms underlying liver injury in jaundiced sepsis patients.

Main Methods:

• Rats underwent bile duct ligation (BDL) or sham-operation.
• Two weeks post-operation, rats received varying doses of LPS (1, 10, 100 microg/kg).
• Hepatic microvasculature was assessed using in vivo microscopy, analyzing leukocyte adhesion, sinusoidal endothelial cell swelling, macrophage activity, and perfused sinusoid counts.

Main Results:

• BDL alone increased leukocyte adhesion, sinusoidal endothelial cell swelling, macrophage activity, and decreased perfused sinusoids.
• LPS administration exacerbated leukocyte adhesion and reduced perfused sinusoids in a dose-dependent manner in BDL rats.
• The hepatic microvascular response to low-dose LPS was significantly enhanced in BDL rats compared to sham-operated controls, though high-dose LPS suppressed macrophage activity.

Conclusions:

• Chronic biliary obstruction potentiates the hepatic microvascular inflammatory response to endotoxin.
• This exaggerated microcirculatory dysfunction likely contributes to liver injury and increased mortality in jaundiced sepsis patients.
• Targeting microcirculatory derangements may offer therapeutic strategies for sepsis in obstructive jaundice.