Bile acid conjugates present in tissues during extrahepatic cholestasis

Area of Science:

• Hepatology and Gastroenterology
• Biochemistry
• Clinical Medicine

Background:

• Extrahepatic cholestasis leads to impaired bile flow.
• Bile acids are crucial for digestion but can be toxic at high concentrations.
• Tissue accumulation of bile acids in cholestasis is not fully understood.

Purpose of the Study:

• To quantify bile acid concentrations in various tissues of patients with extrahepatic cholestasis.
• To compare tissue bile acid levels with serum concentrations.
• To investigate the storage and distribution of bile acids in cholestatic conditions.

Main Methods:

• Analysis of bile acid concentrations in muscle, subcutaneous fat, and skin samples.
• Comparison of tissue bile acid levels with concurrent serum concentrations.
• Use of radiolabeled [24-14C]chenodeoxycholic acid to assess bile acid metabolism and storage.

Main Results:

• Elevated bile acid concentrations were detected in most muscle, fat, and skin samples.
• Specific activity of [24-14C]chenodeoxycholic acid was lower in tissues than serum, indicating tissue storage.
• Some patients exhibited higher tissue bile acid concentrations than serum, primarily due to increased cholic acid levels.

Conclusions:

• Patients with extrahepatic cholestasis show significant accumulation of bile acids in peripheral tissues.
• Tissue storage of bile acids, particularly cholic acid, is a key feature of this condition.
• No evidence of covalently bound bile acids in the examined tissues was found.