Biliary obstruction dissipates bioelectric sinusoidal-canalicular barrier without altering taurocholate uptake

Area of Science:

• Hepatology
• Physiology
• Molecular Biology

Background:

• Extrahepatic cholestasis involves impaired bile flow.
• Understanding immediate barrier changes is crucial for treatment.
• The sinusoidal-canalicular barrier's role in cholestasis is not fully understood.

Purpose of the Study:

• To investigate the immediate effects of short-term biliary obstruction on the rat liver's bioelectrical sinusoidal-canalicular barrier.
• To assess changes in barrier permeability and function during obstruction.
• To determine the impact on hepatic drug and bile acid transport.

Main Methods:

• Utilized molecular weight-matched uncharged and negatively charged inert solute pairs to measure bioelectrical barrier function.
• Induced short-term biliary obstruction in rats.
• Measured inert solute clearances and hepatic drug extraction in vivo and in situ.
• Assessed glycocholate transport and return in hepatic venous effluent.

Main Results:

• Biliary obstruction rapidly decreased the bioelectrical barrier potential.
• Inert solute clearances increased, indicating altered permeability influenced by molecular size and charge.
• Hepatic extraction of actively transported glycocholate significantly decreased, while passive transport of D-propranolol remained unaffected.
• Regurgitation of bile into the blood was observed.

Conclusions:

• Short-term biliary obstruction causes immediate loss of the sinusoidal-canalicular bioelectrical barrier.
• Altered barrier function and bile regurgitation occur rapidly.
• These changes impact the transport of bile acids, contributing to cholestasis pathophysiology.