Endogenous opioids and liver disease

Endogenous opioids modulate hepatocyte apoptosis in a rat model of chronic cholestasis: the role of oxidative stress

“…Several clinical and experimental studies have revealed the elevation of opioidergic neuromodulation during cholestatic liver diseases (11). Increased total plasma opioid activity in addition to high levels of endogenous opioids has been well described in cholestatic rats in several key studies by Swain and colleagues (12–15).…”

“…There is also downregulation of opioid receptors in cholestatic rats, secondary to increased availability of endogenous opioid agonists (16). Enhanced opioidergic tone appears to be responsible for general pruritus and some of the cardiovascular abnormalities associated with cholestasis (11, 17). Increment of opioidergic neuromodulation is also well described in patients having primary biliary cirrhosis (18, 19).…”

New insights into the role of endogenous opioids in the pathogenesis of gastrointestinal and liver disease

“…Studies from the 1980s in patients with primary biliary cirrhosis represent the earliest evidence of a correlation between the plasma levels of endogenous opioids and liver disease 14. This concept led to the observation that opioid receptor antagonists ameliorate pruritus in patients with cholestasis 8 14.…”

“…This concept led to the observation that opioid receptor antagonists ameliorate pruritus in patients with cholestasis 8 14. Although opioid antagonist therapy has since been used therapeutically for the treatment of pruritus in cholestatic liver disease, the physiological basis of its actions has not completely been understood.…”

“…Most of the reported effects of opioids on the liver are mediated by modulation of the central nervous regulation of hepatic function 14. For instance, Roberts et al showed that activation of opioid receptors can decrease hepatic glutathione levels via a central nervous system mechanism 18.…”