Cirrhosis of the liver usually develops as a long-term consequence of chronic alcoholism or viral hepatitis.
It is associated with damage to liver tissue and loss of liver function. Other complications include fluid accumulation in the abdomen (ascites), and increased pressure in the blood vessels (portal hypertension). Vasodilation of the systemic circulation, resulting in low blood pressure, may also occur.
Vasodilated peripheral blood vessels result in a marked increase in mortality. However, conventional medications that counter vessel dilation do not work on cirrhotic vessels.
Now, a team of scientists from the US National Institute on Alcohol Abuse and Alcoholism has discovered that vasodilation in cirrhosis is mediated through receptors for endogenous cannabinoids (specifically CB1).
Using a rat model, they also found that the vasodilation could be reduced, using a compound that blocked the receptors - SR141716A.
Additionally, they have discovered that cirrhotic human livers contain increased numbers of cannabinoid receptors.
|Cannabinoid receptors mediate cirrhotic vasodilation.
The findings point to endogenous cannabinoids, such as anadamide, as being responsible for the cirrhotic vasodilation.
The authors write that, if this proves to be true in humans, antagonists of these receptors might offer a therapeutic approach to the management of patients with advanced liver cirrhosis.