The TGR5 receptor mediates bile acid-induced itch and analgesia

The liver secretes bile acids to aid in the digestion of fats. Cholestasis is a condition in which the bile flow from the liver to the duodenum is impeded. Patients with the disease exhibit itchiness (pruritis) and cannot sense pain (analgesia). The molecular mechanisms mediating these effects are unknown. Carlos Corvera of UCSF and Nigel Bunnett of Monash University discuss their study demonstrating that bile acids cause itch and analgesia by activating the TGR5 receptor in neurons.

• TGR5 is expressed in neurons in mouse dorsal root ganglia and spinal cord, which transmit itch and pain signals.
• Stimulation of TGR5 induced the release of itch and analgesia transmitting molecules, including gastrin-releasing peptide and leucine-enkephalin.
• Intradermal injection of bile acids stimulated scratching behavior that was TGR5 dependent.
• Bile acids activate TGR5 on sensory nerves to transmit itch and analgesia, suggesting that these mechanisms contribute to pruritus and analgesia during cholestatic liver diseases.

[MartinNyberg]

You’re singing my song. I searched on YouTube for how to relieve the itching associated with jaundice, and you’re addressing exactly my situation. I just had my gallbladder removed but somehow the jaundice is not going away. The itching is debilitating nearly. I’m looking for specific answers of course, how to relieve the itching, what to changing my diet, and of course how to relieve the problem with the liver in the first place. My doctors are examining it but no one has mentioned this condition specifically.